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Talk about Newsnight

Ethical Man - Justin Rowlatt

Are domestic wind turbines an eco-con?

  • Newsnight
  • 30 Nov 06, 02:40 PM

turbine203caption.jpgIt is time to talk turbines. Very uncharacteristically I’ve been biting my tongue on the subject as I waited until I got my own windmill. Then last week, just three days before the thing was due to be installed, a representative of Windsave rang to say the company had decided that my property isn’t suitable and that their installers would not be coming round.

Windsave, as regular viewers will know, offered me a turbine back in March when the Ethical Man experiment first began. It is also the company which, with much fanfare, sells its turbines through B&Q. Windsave has promised to come round to my house next Thursday to explain its decision.

But if Windsave isn’t going to put a turbine up then I should put my cards on the table: I am now persuaded – unless someone can convince me otherwise – that domestic wind turbines are little more than an eco-con.

Why do I believe this? Well, it is a question of physics.

I know this is rightfully a subject for my colleague Steve Smith but let me do my best to explain (and I would be very grateful if you could write in if you can improve upon or add to my explanation).

As I understand it (with a little help from the web) you can calculate how much power the wind can deliver with this equation:

Power in watts = (collection area in square feet) x (wind speed)3 x (0.0054)

The problem with domestic turbines lies in that little cube function on the wind speed. Consider what it means: because power is related to the cube of the wind speed, when the wind is blowing hard you get a lot of power but when it drops the output falls disproportionately. Indeed, it rapidly becomes almost non-existent.

The cartoonist, artist and engineer Tim Hunkin explains it very well on his website. Conveniently for me he takes the example of Windsave, the company that had promised me a turbine.

Windsave boasts that its 1.75 metre turbine will generate 1kW of power at speeds of 12.5 metres per second, a pretty strong breeze. Not bad. But what happens when the wind falls? By the cube law, halve the wind speed to six metres per second (a moderate breeze) and you now get 120 Watts – that’s one non-energy saving bulb. Hum, not so good.

My house is on the flanks of the highest hill in London and is relatively exposed but I’m told that average wind speeds are likely to be between 4 and 5 metres per second.

What would that do to the output from my Windsave turbine? At those speeds I’d be lucky to get 25 Watts. That is barely enough for two energy saving light bulbs and nowhere near enough to live up to the company’s promise of reducing my electricity bills by “up to 30% a year”.

So does that mean that wind power is a dead end? Once again that is answered by that equation.

Windsave's website.jpgThe problem with Windsave’s wind turbines (and those of its rivals) is that they are too small. Just as power falls disproportionately when wind speed drops the collection area increases disproportionately as you increase the length of the turbine blades. So a big turbine can generate reasonable amounts of power even in a relatively low wind.

So what is the upshot of all of this? Well, unless these calculations are very wrong my advice to you if you are considering buying a domestic wind turbine is don’t do it. It will probably take more carbon to make the thing than it will ever generate in usable power.

But there is a wider implication too. Micro wind power is one of the ways the government suggests that this country will achieve the sixty per cent cut in emissions that is due to be enshrined in the new climate change bill. The Energy Saving Trust estimates that domestic turbines could supply up 4% of all the UK’s electricity needs and could cut carbon dioxide emissions by 6%.

If my argument is right then those figures are nonsense and the government will need to look elsewhere for the carbon cuts it needs.

This is a pessimistic conclusion. Please prove me wrong if you can.

Comments  Post your comment

  • 1.
  • At 03:03 PM on 30 Nov 2006,
  • James wrote:

Unfortunately, I think you are quite right.

  • 2.
  • At 05:07 PM on 30 Nov 2006,
  • Jeff wrote:

I have a 1 metre wind turbine on my boat to keep the batteries topped-up. I doubt that it will ever produce enough energy to compensate for that used in its manufacture, so it's not really "environmentally friendly", but can be considered to be a reasonable tool for the job only in that there is no other alternative... Unlike domestic mains.

Wind and solar are never going to be an adequate substitute for fossil fuel and/or nuclear in the UK, the obvious question is what do we do on a very cold, still, winter's night?

  • 3.
  • At 05:11 PM on 30 Nov 2006,
  • John C wrote:

I think perhaps intalling windmills on politicians homes and indeed the houses of parliament would be sensible and produce significant amounts of energy. Given the amounts of hot air produced in and around those areas.... also how about on management gurus???

You are absolutely right. As a consulting engineer involved on a daily basis with providing low-energy building design I am continually comparing renewable technologies to see if the numbers stack up. Renewable technologies that are promising in terms of significantly reducing CO2 emissions are certainly available, but micro wind-turbines are not among them. Putting spin on those renewables with marginal impact only serves to damage the ones with real potential to make a difference. In my view, companies that promote such products should be forced to explain in laymans terms exactly what level of contribution they actually make to CO2 emissions compared with business-as-usual annual figures. The last thing that wind turbines need is spin!

  • 5.
  • At 05:15 PM on 30 Nov 2006,
  • Chris wrote:

I think miniature turbines have been oversold, and are too expensive. But your calculations are potentially misleading too.

Given that the power is proportional to the wind-speed cubed, "average wind speed" is not a particularly useful consideration. If the wind blows constantly at 5 metres/second, the power output will be tiny, as you point out - say 20W. If the wind blows at 10 m/s half the time, and 0 m/s for the other half, the average wind speed will still be 5 m/s, but the average power output will be four times as great (80W in this example). If it blows for 20 m/s a quarter of the time, otherwise not at all, the average output will be greater still (320W).

Conclusion? If the turbine can handle gusts, and use the power sensibly, it might be worth it. If it's going to fly off the roof in a gale, it's not worth it!

  • 6.
  • At 05:17 PM on 30 Nov 2006,
  • Al wrote:

You are using an average wind speed to justify that the energy generated is not worthwhile. However, as you stated; your argument relies on the assumption that energy produced is proportional to the cube root of the wind speed. The average wind speed for example might be 4 m/s but, (to simplify) if this is made up of gusts of 12.5 m/s for one minute every 3.125 mins (and still for the rest) then the average output of your wind turbine would be 1KW/3.125 = 320 watts. This is 10 times what your estimate stated.

Just a thought.

a

  • 7.
  • At 05:21 PM on 30 Nov 2006,
  • Gordon wrote:

The reason the government is mad about "micro-generation" is;

A) They're not responsible for it - and can't be help accountable if it fails.

B) It will fail, so there will be no fall in tax revenues from energy production.

They can take Kudos for the policy, then shift blame when it doesn't work.

  • 8.
  • At 05:21 PM on 30 Nov 2006,
  • Stewart Goudie wrote:

Another company that offers a 1.5kW wind turbine, Renewable Devices in Penicuik, states that it produces 2000 to 3000kWh per year. This is worth around £160 to £240. I think their cost is similar to Windsave, around £1500. So payback is around 10 years, or less. Seems a reasonable deal to me.

  • 9.
  • At 05:21 PM on 30 Nov 2006,
  • David wrote:

Do you mean - shock horror! - that perhaps David "Dave" Cameron's turbine may look sincere and as if he's making a statement, but in fact will have very little substantive impact?

  • 10.
  • At 05:25 PM on 30 Nov 2006,
  • Stefan Masters wrote:

If the average wind speed is between 4 and 5 metres per second, then it is incorrect to conclude that the average power output is 25W, as you imply.

For example, suppose the wind blows at 8 metres per second for 12 hours in a day and not at all for the other 12 hours. The average wind speed is 4 metres per second but the average power output is much higher than 25W.

This is because the turbine produces disproportionately more power at higher wind speeds, as you point out.

Having said that, the power output is still not huge.

  • 11.
  • At 05:25 PM on 30 Nov 2006,
  • Chris Davis wrote:

Not quite as simple. You need to think about the average of the cube of the wind speed which is not the same as the cube of the average wind speed. e.g. if over a period of three hours you get three wind speeds of an hour each in length and your speeds are 1, 3 & 5 mph this gives an average speed of (1+3+5)/3 = 3mph and therefore a cubed average of 9. If we average the cubes however we get (1+9+25)/3 = 11.67
That's a very simplistic scenario as the true calculations will need diferential equations and more data but the average of the cubed instananeous wind speed will usually be higher than the cube of the average as long as the wind speed is greater than 1mph (I don't know what units the power calculation is in, I've assumed mph).
I still don't think it will be enough mind.

Yeap

I installed a wind turbine £300 when I moved to a boat in 1985 with my small family.

The unit was much smaller and produced less than 5% of the small amount of electricity we used.

I then invested in photovoltaic cells.
2 x £300 about 1 sq.metre.

The difference was staggering they provided more than 80%
No moving, dangerous blades. Work fair in dull weather. lasted 20 years so far.

Don't bother with wind grab the sun
:)

I now use 3 x photovoltaics and my wind turbine is under cover. hardly worth the effort of mounting it.

  • 13.
  • At 05:27 PM on 30 Nov 2006,
  • Steven wrote:

I do not have the article to hand but I also believe that there questions as to whether large wind turbines actually save any carbon. So I cannot prove you wrong!

  • 14.
  • At 05:30 PM on 30 Nov 2006,
  • David wrote:

A much better bet for reducing carbon emissions is solar heating. I have solar panels which provide hot water - at times scalding water - from mid-May to mid-September. For the rest of the year there is always some contribution from the installation. The benefit is no need for oil or electricity during the summer months.

One of the benefits of the hotter summers we have been promised is even more hot water!!

Justin, had Windsave previously said that your house was suitable? Or was this the first time they considered it.

I know B&Q say they will survey a site first and tell you if it is suitable. If it isn't there is a refund.

But of course they are at risk of losing the sale, so I would be suspicious of quite how unsuitable a site would normally have to be before they cancelled the sale.

If it turns out that based on the advertised returns on a Windsave turbine, 99% of houses are unsuitable, they are going to be doing a lot of fruitless surveys!

  • 16.
  • At 05:37 PM on 30 Nov 2006,
  • Edward Byard wrote:

Micro-generation is a misnomer for the majority of the population. "Medium-generation" (not an official term) by large turbines feeding a local area are the way forward, as many other European nations have realised and already implemented. We need a big change in planning laws and public attitudes to realise this. The UK is windy enough to generate sufficient power for the whole of Europe (in theory) so we have ample opportunity to generate enough for ourselves. Nuclear etc are a waste of time and money. Time for a wind of change.

  • 17.
  • At 05:39 PM on 30 Nov 2006,
  • Simon wrote:

I would be interested to know more about solar panels especially the water heating variety. Perhaps ethical man could install those instead. I never really imagined a small wind turbine would generate much electricity. A larger turbine on top of say council offices would be more practical. Huge turbines on local industrial estates could be used to generate hydrogen for local buses to re-fuel. I think we need to be practical so people take micro generation seriously.

  • 18.
  • At 05:40 PM on 30 Nov 2006,
  • Vince Tartrazine wrote:

Watts (!) your average power consumption? Chris has explained your average output could be higher and this could well be on track for 4% of your domestic needs - or more, so EST is kind of in line...

  • 19.
  • At 05:52 PM on 30 Nov 2006,
  • Aruna Seneviratne wrote:

As kid I used to think, why don't they build big towers to catch all the electricity in lightning? Now, as an engineer working in renewable energy, I realised that building machines to capitalise on very rare occurances doesn't pay off.

By relying on gusts, you have to design a turbine to be strong enough to withstand very high forces that it encounters very infrequently, ending with an expensive machine, that doesn't end up converting much more energy.

By designing for the average wind power, and shedding wind above that you may halve the cost of the turbine while still capturing the majority of the energy in the wind. And that makes both technical and economic sense.

How much electricity do you use?
25 watts, 24 hours a day turning the meeter backwards, would be about 10% of our use.
Not 30%, but a home which was a bit more exposed than yours and a bit more efficient than ours would look to be in with a chance.

  • 21.
  • At 05:59 PM on 30 Nov 2006,
  • Mike wrote:

I am looking at a 5.4m 6Kw turbine. It will need a 12m pole! So at 5.1m/s what will the power output be? If it's not 6Kw, then all of the turbine sales companies are mis-selling their equipment. Or have I missed something?

  • 22.
  • At 06:28 PM on 30 Nov 2006,
  • Patrick Calthrop wrote:

Very interested in this as have just applied for planning permission to install a Windsave turbine (awaiting this before getting the survey).

One point worth mentioning is that the turbine starts to cut out automatically once windspeed exceeds 14-5m/s and you need 3.5-5m/s to turn it at all.

However, Windsave's website confirms your 1 kW @ 12.5m/s figure but estimates 800-1200 kWh/year should be generated nontheless; this equates to only 2.2-3.3 hours per day at the 12.5 m/s. Or, 17-26 hours per day at 6.25 m/s.

As a previous blogger semi-pointed out, this may be explained by the fact that the cube thing works for you in the sense that you only need a few windy hours to bump up your average power a lot, far more than it bumps up your average wind speed.

So I reckon both you and Windsave could be right. Anyone else ?

  • 23.
  • At 09:12 PM on 30 Nov 2006,
  • Spartacus wrote:

Justin, you need to consider the average cube ... oh, I see we've covered that.

While I agree with others that you've probably underestimated the output, my suspicion is that micro turbines don't make much sense in many urban areas, where other options are usually more sensible. In windy rural areas they could be worthwhile, but then bigger turbines would be even better.

(Having said that, it's currently blowing a hoolie past my flat in Edinburgh, so there might be exceptions.)

I think we can only settle this argument by finding out some real data from wind turbines installed in various locations. Anyone?

  • 24.
  • At 09:44 PM on 30 Nov 2006,
  • Jonathan Albery wrote:

It is also worth considering that the energy produced by the turbine will be used at the point of generation. Whilst this wont affect you electricity bill, or the financial ‘payback in x years’ exercise, it will influence the total carbon-cost equation.

When you switch on a light, you are using the energy generated by an event such as the burning of coal. This often occurs many miles from the point of use. In the course of travelling this distance, and going through various different transformer sub-stations etc. much energy is lost. I forget the exact percentage, but I know it is large enough to be considered. Therefore the energy required to power a 60W light bulb is substantially more than 60W if supplied by a power plant. Locally generated power clearly does not have this problem of energy loss, and presumably there is a corresponding (albeit tiny on an individual basis) reduction in construction and maintenance (and therefore associated carbon) on the power-supply infrastructure. If adopted on mass this could well be significant.

  • 25.
  • At 11:01 PM on 30 Nov 2006,
  • Jon Blacklock wrote:

I think the key here and as has been mentioned here is a portfolio of generation mechanisms. I look out on the largest offshore wind farm currently with another array being built. There are also turbines at Seaforth docks. In both cases it is rare that the turbines are stationary. Combine this with conditions that cause calm weather...high pressure...this normally means "clear" skies (relatively speaking in a maritime climate). These conditions mean PV and Solar Water heating are more efficient. Combine this with ground source and Combined Heat and Power and emerging technologies such as biomass etc then we get a range of possibilities. The key to this is all is the "economics" and "carbon cost" of the technology...oh and a govt with courage and foresight to put some real investment into renewables.

  • 26.
  • At 11:18 PM on 30 Nov 2006,
  • Physics literate wrote:

One important point to consider is that the average wind speed is different in urban and rural areas.

The average speed of the wind is much higher in the countryside due to the 'flatness' of the terrain, this is the reason why wind turbines in Chelsea will be forever useless.

This is also why turbines nearly always have to be built in 'picturesque' towns where they're not wanted.

  • 27.
  • At 11:34 PM on 30 Nov 2006,
  • Mike Whitecross wrote:

I am an engineer and believe you to be absolutely right.Please press on with this campaign.
Also, please now turn your attention to the marketing of solar panels which I believe to be similarly non cost-effective in the UK.

Mike

  • 28.
  • At 11:35 PM on 30 Nov 2006,
  • Glen wrote:

Jonathan A., locally generated electricity will suffer from power loss over distance, albeit shorter distances than the national power network.

Over long distances it is cost effective to use large diameter cables and high voltages to minimise losses, over short distances these won't be used, so losses will be in a similar region.

  • 29.
  • At 11:35 PM on 30 Nov 2006,
  • Trout wrote:

I'm not an expert on solar power, but I thought one of the problems with it is that the chemicals used in the cells are quite toxic. So if solar power was to be used on a large scale you could have problems with pollution if solar cells were to get broken leaking the chemicals, as well as disposal issues. Anyone know anymore about this? I suppose though if solar panels last decades its not such of a big issue.

  • 30.
  • At 12:02 AM on 01 Dec 2006,
  • Rick Rogers wrote:

I installed a small windmill at my cabin on an island in lake Michigan about 30 years ago. It was always needing maintenance and didn't product much. I took it down and installed PV panels. They are still working great and I've barely touched them.

  • 31.
  • At 12:06 AM on 01 Dec 2006,
  • Chris Linthwaite wrote:

I always thought that the Green energy lobby for producing micro amounts of energy using wind power is a con, because of the amount of energy that would be required to produce wind turbines for every single home in the country.

Another factor is that most houses are built in a linear fashion along a road. As most houses on most roads are of the same design the anchor point for the wind turbine would be placed in the same spot.

Wind power is not finite in the fact that wind turbines take energy from the wind. So if you have wind turbines set in a line the amount of energy from the first wind turbine compared to the second wind turbine reduces as various factors eddys etc take effect. This continues down the line.

If you want to produce your own energy much better to use photovoltaic cells.

Anyone thinking of buying a wind turbine don't bother, unless you have a farm and you can put a really big one nearby.

  • 32.
  • At 12:24 AM on 01 Dec 2006,
  • Dominic wrote:

Don't worry about cubic equations and wind power distributions, we have a much simpler tool that enables us to understand if a micro power windmill is beneficial - money.

A windsave turbine costs £1500 installed. Assuming it generates 0.2Kw average, lasts 10 years (as advertised), electricity costs 7p per Kwh from the grid, then the total "saved" is 0.2Kw * 8760h * £0.07/Kwh * 10 years = £1226. So, ignoring the cost of capital deployed over the 10 years (which is nearly £1000 on its own), the total loss from installing a micro turbine is only £274!


  • 33.
  • At 12:25 AM on 01 Dec 2006,
  • Mitch wrote:

A good source of general information on the subject of Wind Power is
http://www.otherpower.com/otherpower_wind.html
Looking around on their site, it looks like they recommend putting the wind turbine as high as possible in order to avoid ground turbulence. I suspect sticking a turbine on a chimney stack on a house in a housing estate is going to suffer from major turbulence problems and be pretty ineffective. Where I see micro-turbines being a possibility are on the tops/sides of tall structures or large structures that collect and funnel wind (like some office blocks or shopping centres I have been to). Another possibilty is to put a larger (say 10kW) Wind Turbine in school playing fields. Unfortunately, for the vast majority of urbanites, micro-generators look like a red-herring, which will take well in excess of 15 years (if ever) to save the carbon that they cost to produce and fit.

  • 34.
  • At 12:47 AM on 01 Dec 2006,
  • Fred wrote:

The efficiency of wind turbines – particularly horizontal axis turbines such as these - is greatly reduced by turbulence.

The wind flows around buildings are extremely turbulent.

For that reason alone these small turbines will go down in history as an expensive con and just publicity stunt by politicians.

Even in rural areas a turbine should be installed on a high mast to place it in a laminar air flow - and at height where the wind speeds are faster.

An expert on this subject is Paul Gipe http://www.wind-works.org/
It is worth reading some of his articles at
http://www.wind-works.org/articles/small_turbines.html
before wasting money.

  • 35.
  • At 12:58 AM on 01 Dec 2006,
  • Craig Allen wrote:

A friend of mine living on the Southern Victorian (Australian) plains has a wind turbine. Most of the time it produces little electricity. During our windy gusty Autumn the thing spins so fast it howls and at these times contributes significantly to their household electricity budget. Unfortunately a falcon recently flew into it during a gust and ended up very mangled. Those things should have safety cages fitted as standard.

  • 36.
  • At 01:04 AM on 01 Dec 2006,
  • Spartacus wrote:

By the way Justin, the Energywatch website tells me that average household electricity usage is 3300 kWh. There are 24*365 = 8760 hours in a year, so average household demand is 3300*1000/8760 = 377 watts.

So a mean output of 120 watts (assuming the turbine could achieve this) could indeed reduce the average bill by about 30%.

I don't want to get into an argument about the potential output of micro turbines. I'm just pointing out that the 120 watt figure you quote is more significant than it might at first appear.

  • 37.
  • At 01:48 AM on 01 Dec 2006,
  • Bill wrote:

I think what happened here was that the company made promises before checking out your location, and after your plans were made public, they had to be cancelled. I would have been emotionally scarred (by the way, I never use my real name).

it's true there's a lot of urban legends, that don't do service to domestic windpower. But to compare the output to large commercial machines is unfair unless you have the same "windscape". Wind farms are located where wind is financially predictable. Anyone who wants to support the idea without fear of being scammed, can buy shares in wind farms and take the proceeds off your electric bill. (true, anything's scammable, so study their prospectus & get 2nd opinions). So far as the cost of carbon, there's plans online for low tech wind generators that use recycled and non carbon consuming materials, like used auto parts and wood. The long view in any case will be to reduce consumption, so we don't need 20kw/hr.

  • 38.
  • At 01:56 AM on 01 Dec 2006,
  • Jenny wrote:

Edward Byard wrote: "...The UK is windy enough to generate sufficient power for the whole of Europe (in theory) so we have ample opportunity to generate enough for ourselves. Nuclear etc are a waste of time and money. Time for a wind of change."

I would be interested to see official figures on how climate change is affecting winds over the UK. My own impression, near the coast, where wind was always blowing my hair and now there rarely seems even a breath to provide ventilation in the ever longer summer heat, checked with friends in Ireland to the west, is that we're having much more almost windless weather at ground level. Sales of electric fans have certainly soared.

I notice, incidentally, that there have still been no new nuclear power plants ordered, but a new gas one has been.

  • 39.
  • At 01:56 AM on 01 Dec 2006,
  • Richard Hagen wrote:

Hi, I am a wind energy enthusiest from the U.S. I make CNC wooden wind turbine blades in a variety of sizes and designs, some of which have been used in teaching airodynamics courses here in the U.S. I have also written a short article on power in the wind previously, and it is available at: http://www.otherpower.com/images/scimages/742/02_power_in_the_wind.htm This article explains how the kinetic energy in the wind can be calculated, and relates this to the swept area, and hence the blade diameter of the turbine, along with charts for various diameter machines. You have my permission to utilize and edit this material as you wish should that be of use to you. Wind is better matched for rural areas because of the size of the machine needed to contribute a meaningful percentage of the dwellings energy usage. Where I am at most areas have average wind speeds of about 11 miles per hour, or a little less than 5 meters per second. One can still utilize wind power in such areas, if one can install a machine with a diameter greater than at least 3 meters diameter. Comparing U.S. economic costs against grid power, an even larger diameter would still be needed to become cost competitive. Therefore, from an economics stand point, smaller wind turbines only make sense for remote power applications, where grid power is not available, or for experimenters such as myself. This will likely only change if other sources of power become much more expensive. For the economics of wind power, bigger truly is better. Rich Hagen

  • 40.
  • At 02:16 AM on 01 Dec 2006,
  • Shelby Rogers wrote:

As a scientist who worked for the US Dept of Energy for 30 years, I find many of the comments made to be very good and interesting. However, in a much broader view, I find many of the comments to be irrelevant. Most investigators only look at their particular area of interest and not at the big picture. They don't appreciate the horrendous amount of fossil energy consumed in the world or even the amount of nuclear energy consumed. Wind and solar energy will and should grow as much as is reasonably possible. However such growth will be a relatively small drop in the bucket for the next several decades. And maybe for the next 100 years.

  • 41.
  • At 02:22 AM on 01 Dec 2006,
  • Fred wrote:

Simon wrote:
"I would be interested to know more about solar panels especially the water heating variety. "

Take a look at these very efficient water heaters:

http://www.apricus.com/

Also, solar electric (Photo Voltaic hence PV) panels have been very expensive due to the high demand for the silicone wafers with which they are made, but there is a lot of manufacturing capacity being built and over the next few years the price should come down to a level that will make them cost effective to use in the UK. There are also some innovative manufacturing techniques being developed that will bring the price down to the point where whole roofs and / or walls can be covered with PV arrays.

  • 42.
  • At 02:25 AM on 01 Dec 2006,
  • bilal mansoor wrote:

a few years ago, i was working in a small coastal rural area in pakistan carrying out some basic surveys. the village that i was staying in was off the beaten path so to speak. the only way to get to it was by an unmetalled, unpaved road and by either walking, biking or taking an off-road vehicle. anyways, that small village had no electricity provided by the government. the 20 or so households there pooled resources together and bought a wind turbine. they were able to generate enough electricity to provide all the houses with at least a light bulb for a few hours during the day and at times a fan.
so, the point of this entire long statement was that when traditional electricity mechanisms are unavailable or not cost effective for providers, wind turbines might just make sense. PV cell were i believe too expensive for that community. of course, we're talking about a small isolated village in a third world country. not quite the same context as that of the UK.

  • 43.
  • At 04:32 AM on 01 Dec 2006,
  • Andy Pix wrote:

A couple of people were asking/talking about solar water heating. Here in Australia a very popular system is Solahart. You see them on roofs all over. I've had two installed (on different houses that I've lived in). Not plugging the specific brand, but they are excellent. If you can't get them in Blighty then start importing them folks !

  • 44.
  • At 07:01 AM on 01 Dec 2006,
  • Keith Chadwick wrote:

Has anyone ever calculated the recovery time for the power required to manufacture/install a small-scale wind turbine?

  • 45.
  • At 07:33 AM on 01 Dec 2006,
  • phil wrote:

You are correct yuo would be better fitting a heat pump inverter airconditioiner to your house for heating it is expensive but it is claimed to be three yes three times more efficient than the latest gas boiler. there is also technology on the market to provide domestic hot water from a heat pump system.

  • 46.
  • At 07:36 AM on 01 Dec 2006,
  • Ivan Grey wrote:

I have been living in Athens, Greece for two years now. On a roof top you see solar water heats. These heaters however are only used for heating bath water. During the summer when we have plenty of sun we don't need hot water and during the winter with the reduced sun they are not sufficient for heating a house and are not configured to anyway. Using the solar water heater more efficiently during the summer to make electricity when the hot water is not required would be an obvious step. Fossil fuels are running out and nuclear fission reactors are dangerous and due to the cost of decommision are unpracticle (not to speak of their waste). Any form of renewable energy is going in the right direction.

  • 47.
  • At 08:17 AM on 01 Dec 2006,
  • Steven Walker wrote:

Absolutely spot on !

Don't doubt the maths; it is absolutely true

We have forgotten the "good old days" of windmills, and we have lost the lifestyle that went with it.

When the wind blew, the miller would work round the clock, grinding corn.

When it didn't blow, he packed up and went fishing. Simple as that.

We have forgotten that lifestyle, and we'd waste more carbon building these toys than they would ever save in electricity

  • 48.
  • At 08:18 AM on 01 Dec 2006,
  • Les Upchurch wrote:

Another point which has not been covered in this discussion is that the wind quite often comes in gusts. The turbine is connected into the mains electrical system and when the turbine starts to generate electricity there is a significant time lag before the output can be synchronised to the mains and produce useful electricity. By this time the wind may have died down again. Also, below a certain level the output is shut off completely, thus reducing useable output even more.

  • 49.
  • At 08:19 AM on 01 Dec 2006,
  • michael walsh wrote:

want cheap electricity? The motionless electric generator, or over unity electric motors,(as developed by Hitachi). See tom beardons' web site .
Mike

  • 50.
  • At 08:23 AM on 01 Dec 2006,
  • M. Thompson wrote:

The general consensus seems to be that there will be more violent and more frequent storms in the future, so maybe these wind turbines will become a more attractive proposition when climate change has progressed to a point where strong winds are much more frequent.

  • 51.
  • At 08:33 AM on 01 Dec 2006,
  • Laurie wrote:

Of course the argument has to be about the alternative to wind, solar or just plain energy saving schemes; that is the government's (or at least its leader's) apparent conversion back to the nuclear option.

If the alternative to slighly higher fuel bills is poisoning the planet with nuclear waste for the next 100,000 years with fission waste; then I say let's spend the money the goverment wants to use building these potential terrorist targets with a long history of accidents Windscale 1957, Three Mile Island 1979, Chernobyl 1986 on grants to safe small home energy production.

  • 52.
  • At 08:49 AM on 01 Dec 2006,
  • George Baxter wrote:

You are absolutely right. It is a con and I have been saying the same on other forums. There was a Channel 4 programme earlier this year called "it isn't easy being green". A lot of people were "persuaded" that wind and solar are viable. They are not in the UK. You may just get something down in Cornwall, as that has the most sunshine and lots of wind. Otherwise, you are better off spending the money on better insulation.

Would you also be prepared to look at solar energy? There is a newish innovation called a vacuum tube solar panel. It does sound more promising than the flat plate collector. But it will still only produce hot water in the summer, when the need is the least. Go for nuclear fusion power as the only clean long term solution!

  • 53.
  • At 09:08 AM on 01 Dec 2006,
  • Ian wrote:

Now this type of blog drives me absolutely crazy. While I appreciate the warning on micro generation wind turbines this with so many other views leaves me perplexed as to what type of micro generation I should invest in.

Having implemented all of the energy saving solutions I know of I now want to change my supply but there are so many conflicting stories.

I suggest this article is half finished and needs to be completed with 'dont go for wind turbines go for...' with an order of prioritiy based on the carbon footprint of the solution.

Don't talk about what we should not do help us understand what we should do.

  • 54.
  • At 09:12 AM on 01 Dec 2006,
  • Andy wrote:

I too would like to see Ethical Man explore solar options rather than wind power. In many foreign countries I have travelled to I have often seen solar panels for domestic water on the roofs of homes. Surely these would work fine during the British summer, and contribute at least something in the winter? Also, how easy is it to install solar electric panels? How expensive and/or inconvenient might it be?

  • 55.
  • At 09:13 AM on 01 Dec 2006,
  • Ian wrote:

Surely Newsnight can do a simple experiment over a year or more, by getting people to install turbines on Windsave-approved houses? Obviously without Windsave knowing that they are doing it for Newsnight when they apply.

I don't know how many would be needed to make a statistically useable answer, but a selection of locations across the UK would be intresting.

  • 56.
  • At 09:29 AM on 01 Dec 2006,
  • Dave wrote:

I built my own solar heater out of scrap copper tanks, bit of wood, some unwanted double glazing, and loft insulation. It raises the temperature of mains water before it goes for futher heating (if required) in my combi boiler. It works really well, it doesn't have to be a warm day just needs good light. I can imagine the manufactured units are even more efficient.

  • 57.
  • At 09:34 AM on 01 Dec 2006,
  • Mike Fortescue wrote:

What is wrong with Hydro power which would alleviate the water storage problem together with supplying power?

  • 58.
  • At 09:44 AM on 01 Dec 2006,
  • Danel wrote:

I live in trusthorpe, nr mablethorpe and there are 16 full sized wind turbines. I have to say that they do not create a huge amount of noise and i would rather see any wind turbine up in the countryside whether it be big or small rather than a massive powerstation. People who i speak also share the same view as me.

  • 59.
  • At 09:51 AM on 01 Dec 2006,
  • Les Upchurch wrote:

I think the way forward for the average UK household will be electrical solar energy generation. At the moment it is ludicrously expensive, but then so were flat screen LCD TV's. In only 5 years the price of these TVs has dropped from over £5000 to under £1000. If only the same drive and energy could be put into something more useful like solar power generation.

  • 60.
  • At 09:56 AM on 01 Dec 2006,
  • Debbie Wilson wrote:

I have a wind turbine in Spain, providing all power for the house and stables, it generates so much power that I have to put my security lights on and even turn the turbine off. it is not connected to any grid. The UK is years behind in its thinking, every house should have one even if it is small, this would make a considerable difference to the grid, pensioners who cannot afford and the future of the world.

  • 61.
  • At 10:15 AM on 01 Dec 2006,
  • john wrote:

I looked at this too and calculated that it was not worthwhile. I also wondered what happened to the electric meter when a gale blowing in the middle of the night was producing more power than being consumed. I assume that the power goes into th grid, but does the meter go backwards???

  • 62.
  • At 10:20 AM on 01 Dec 2006,
  • Prab wrote:

I do think wind generators can offer a clean and cheap alternative to carbon fuel generated electricity. I agree with your conclusion with regard the small home windmills but bearing in mind where you live it is not worth your while installing such a generator. But there are coastal areas that are nearly always windy and there would be a clear gains from using private windmills. I believe the way forward is a combination of solar panels and windmills plus the carbon fuel generated power. Working in harmony they can combine to provide all our power needs whilst reducing carbon emisions.

  • 63.
  • At 10:22 AM on 01 Dec 2006,
  • kevw wrote:

"Dave wrote:
I built my own solar heater out of scrap copper tanks, bit of wood, some unwanted double glazing, and loft insulation."

I found a link which may be useful - explore the site as there are various ideas
http://www.thesietch.org/projects/solarthermalpanel2/index.htm
...they mention a heat inverter which would improve efficiency but don't give any clues on building one of those for yourself...

  • 64.
  • At 10:28 AM on 01 Dec 2006,
  • Robin Almond wrote:

I suspect that a similar argument could be used for the large ones as well. Here in the fens of Cambridgeshire we're seeing dozens of 'wind turbines' being errected, and I've watched tens, possibly hundreds of tonnes of concrete and steel going into their foundations, never mind the turbine itself.

Nobody will give me any idea of how long it'll take for the turbine to generate enough 'clean' electricty to pay for the carbon emissions produced by manufacture of the 'dirty' steel and concrete. I can't help wondering if that's because it's (a) embarassingly long or (b) it never actually does, and we'd all have been better off using the coal in a power station and not cement and steel works.

I'd like someone to prove that I'm a pessimist with Luddite tendancies, but I fear they can't.

  • 65.
  • At 10:33 AM on 01 Dec 2006,
  • Bill Watts wrote:

I understand the sense of helplessness of what is the right thing to do. Having saved energy ( it may be better to buy a new efficent fridge than some microgenration) what to do? Solar energy is predictable but wind energy, particularly in an urban environment is not. Commercial wind farms do site surveys of wind. The capital cost of a commercial wind turbine in a windy site is around 25p to deliver 1 kWh a year. A solar PV panel will cost £4 to £6 to deliver the same. The equivalent for a domestic turbine may be 60p per kWh a year for a croft in the Orkneys or £100's per kWh/year for a house in Chealsea. Cheapest is to invest in large turbines on windy sites. For stuff on your house is depends how windy it is. However in all cases storing the energy is going to become the issue when we move towards more renewables.

  • 66.
  • At 10:34 AM on 01 Dec 2006,
  • clive, wrote:

Having read a stack of stuff on micro-generation over the last year or so (and I would recommend everything that Greenpeace has pubished on de-centralised energy generation) it's clear that a wind turbine in any context has to be one part of multiple sources. Wind turbines are most effective when the blades are at least 6 metres above ground and have clear space around them, so any urban configuration is going to be grossly inefficient, particularly if it is retro-fitted. This does not mean we should not promote them but we should do so recognising their limitations. The big picture is that all building codes will have to be revised for the future, and that's a big problem for our government, who are patently schizophrenic in their approach. On the one hand promoting population growth and on the other hand accepting that the classic 3/4 bedroom semi with garage, parking space and a patch of garden space front and back is the way forward. Quite simply, the 2 are mutually exclusive. The future lies in much more densely populated urban areas with PV, local CHP, ground heat, heat stores and wind turbines built into the codes for new bulidings. Sorry to all aspiring sub-urbanites, but that's the way forward that we will have to get our heads around.

  • 67.
  • At 10:37 AM on 01 Dec 2006,
  • Carl wrote:

The cost recovery time for any of these technologies (also heat pumps and insulation) depends on the cost of mains electricity and gas. If prices continue to rise dramatically, alternative energy will soon be a lot more viable. Maybe this will be the impetus we need to take real action on climate change; neither individuals nor governments seem to have made much progess so far.

Well said. I have been waiting for someone to catch on to the current crazy renewable thing. Our companies studies show that typically 54% of energy in buildings is used when there is no one on the property. That surely points to a potential saving of at least 40%. Also if this energy is wasted at least half of any renewable energy created at the same location will also be wasted. Cure energy waste first, get the big reductions in emissions then look to renewables.

I have a 6kwh turbine on my property and it does generate significant amounts of energy. As i left for work this morning it had already produced 20kwhs from midnight to 7.00am.

The problem seems to be this country's (and it is only this country - take a trip round europe or even the carbon monster USA and see) absolute horror at the idea of having industrial sized wind farms as it might "ruin the landscape" or some such.

I think those self same people should have a nuclear power plant built in their locality, and then see if they'd prefer the wind turbine.

  • 71.
  • At 10:49 AM on 01 Dec 2006,
  • Kieran wrote:

Your calculation are most likely right but as with most things in life the only way to be sure is to build it.

It does seem to me that we as a nation expect things to just work: turn key, hit the ground running, etc. If it is not economic this minute, this day, this year then it is not worth doing. Tilting trains, jet turbine even computers are but a few examples. Often technology takes many years if not decades to perfect. So in answer to post no 40, I believe we have got to start somewhere and if not here then were? Yes the task may be massive but if we don't take the fist steps we will never get there.

And yes I agree PV cells look promising and there are many other technologies including: carbon capture, biomass, fission (of lighter elements), fusion, zero point and technologies and to improve efficiency: heat pumps, hybrid cars, electric cars, hydrogen fuel cells. Some are more speculative than others but I can almost guarantee none will just work from day one. Each will take years minimum to perfect.

Sometimes economics does not serve us well.
To be always looking at the present from the point of view of the past tends to lead to stagnation.

In answer to the environmentalists who say we should go back to the old ways. For most of the population the old ways were not some utopia of knights ladies and castles or ladies in country houses waiting for their prince charming. No it was starvation, hypothermia, black death. When disease did not kill of the surplice population a European war would. More than any other thing energy removes want and conflict from the world. Lack of energy does the opposite.

In essence in ten years time wind turbines will most likely be better and as such need to be supported now, as all technologies do.

  • 72.
  • At 11:02 AM on 01 Dec 2006,
  • sean wrote:

Yes, I think you are correct. But suggestions I have heard lead me to believe that in future when the wind speed is high,it may be possible to sell any excess energy back into the grid. Therefore it is an energy harnessing system, which could successfully harness energy when it is available, managed in a way which could make it very cost effective for the owner.

The undoubted worldwide expert on these things is Hugh Piggot at Scoraigwind. He has had lots of information on his web site about the false claims for years.

I have 400watts of solar panels and a 300watt windmill in an urban location. These charge a 1000aH battery bank and I run all the house lighting of this system. My personal experience confirms that the current generation of micro turbines are dramatically over hyped.

Huw Edwards

  • 74.
  • At 11:14 AM on 01 Dec 2006,
  • PAT LAVELLE wrote:

Someone said you can save £160 pounds per year,so in ten years time you start to save,after paying out £1500 to start with,,does the turbine last 10years? how long is the guarntee?would it be a never payment of £1500 per 10 years? no saving at all then.

  • 75.
  • At 11:26 AM on 01 Dec 2006,
  • Dave Moss wrote:

Small wept area, three bladed propeller type wind turbines mounted to the roof of the average three bed cemi in the UK is a not worth while.
These manufacturers use wind tunnel results and pure theory to justify the sales of their products and produce unrealistic return on investment scenarios.
Average wind speeds can be misleading, as has been mentioned by others. 10 days a 5m/s produces considerably less than 5 days at 10m/s added to 5 days of 0 m/s even though the average in both cases is the same.
The real killer to propellers in urban environments is turbulence. Turbulent wind in urban environments is what you get in the real world. If the useable power generated from a large representative survey were monitored over a period of one year and this figure was divided by the total swept area of the units involved, then there might be some furrowed brows. Such a survey of 95 of the worlds larger class of turbines, manufactured by the most well known names in the industry, located in prime coastal and marine sites somewhere in Northern Europe reveals that, for every metre squared of swept area they generate an average of 860kWh/year.
The question is this, if the largest most efficient turbines in the best locations available only average 860kWh/year/metre squared of swept area then, how can a turbine of less than 2.5 metres squared of swept area hope to produce 10,000 kWh/year in the middle of a housing estate?
My suggestion is if you want a weather vane stick to the traditional cock or Old Father Time or if you want a windmill in your garden, stick it with Gnomes where it belongs. As for David Cameron, where does he think he lives, Trumpton?

  • 76.
  • At 11:35 AM on 01 Dec 2006,
  • Stephen Spain wrote:

I looked into wind turbines last year and my head is still spinning. Sales blubs make huge claims, sceptics are out to discredit anything eco-friendly and even the experts disagree.
I eventually concluded the WindSave turbine was too small, but that the Swift turbine from Renewable Devices could be worthwhile. The 'cube rule' means that even though it's just a little bigger it can generate quite a bit more power. It's generation capacity may not be huge, but until you can get significant solar pv installed for £1500 there could be an honest market for it.
The only real test for these devices is to install them and measure the output. So, Justin, please, please, please, pursue this topic further.

I still think my idea of combating both global warming and the obesity crisis at the same time by disconnecting houses from the national grid and installing human-sized hamster wheels linked to storage batteries is still the best bet.

  • 78.
  • At 12:00 PM on 01 Dec 2006,
  • Dave wrote:

Have a look at http://forum.downsizer.net/about15968-0-asc-15.html for a technical disussion. One of the problems is that Windsave are claiming an output very very close to the theoretical possible one

  • 79.
  • At 12:13 PM on 01 Dec 2006,
  • Peter wrote:

Power in watts = (collection area in square feet) x (wind speed NO UNITS)3 x (0.0054 NO UNITS)


Assuming the websites you gathered this from mean wind speed in mph, and dry air then they seem to be assuming ~50% efficiency of the ENTIRE process - i.e. bringing the the air to a complete halt and capturing half of that energy as useful electricity. I reckon that's optimistic.

Someone earlier mentioned "medium generation" rather than micro generation. The Wind Turbine at the Green Park business park near the Madjeski Stadium in Reading is a great example providing power for the equivilent of 1500 homes. The turbine has produced almost 2.5million kilowatts of power in the last 12 months, apparently.

It's certainly less of an eyesore than Didcot powerstation the other source of power in the local area, and for those who worry about ruining the landscape...I think mass migration, resource wars and flooding caused by climate change will radically alter the landscape of this country and many others.

  • 81.
  • At 12:17 PM on 01 Dec 2006,
  • Adrian Bright wrote:

It is going to be most energy efficient/cost effective to encourage large numbers of individuals and households to do their best to reduce energy useage before wasting money on installing tiny and infefficient alternative energy supplies.
It's not rocket science to reduce energy useage in the most energy efficient way:
If just 50% of the population
>turned down their central heating and hot water by a couple of degrees
>made sure all their TV,s videos, computers and hi-fi's were switched off when not in use
>replaced their standard light bulbs with low energy (BTW that isn't the same as "low voltage" which are often "high" energy) versions when they die
>used continental style low temperature washing detergents
Those four would probably reduce national energy consumption by about 10%, and save consumers money very painlessly.

  • 82.
  • At 12:18 PM on 01 Dec 2006,
  • Alan Brown wrote:


As many have said, the small turbines are not worth their while - every calculation I've seen indicates that the minimum economically viable size for a house turbine is 3 metres and ideally 5 metres - which the neighbours WILL complain about.


For small wind turbines, a propeller-based turbine is overcomplex anyway, far better to use designs resembling spinning clotheslines or maypoles that can be several meters high, are self reulating in terms of overspeed and are far less visually unobtrusive than a classic windmill design.

The same applies to home solar photovoltiac - it's still not economic.... YET - but may be in 4-5 years if several recent nanotechnology breakthroughs prove viable in manufacturing.

  • 83.
  • At 12:21 PM on 01 Dec 2006,
  • Gareth wrote:

There's another issue that I'm not sure has been mentioned yet and that is that the equation that was featured in the article assumes (presumably?) that the windmill is 100% efficient at transferring wind energy into electricity. Unless this has already been taken into account? Either way the windmill, friction in the gearing mechanism, it's connection to a DC motor or whatever, all the wiring and even the energy storage setup will all contribute towards energy loss from the system before we get the electricity we want out of the other end.

Great post Justin, and also really useful comments above too.

We're trying to sort the wood from the chaff to find micro generation products that make good sense for householders to get into.

Our website profiles several of the small wind turbines around at the moment.
http://www.bettergeneration.co.uk/generate-energy/home-wind-turbines.html

We also have a page that compares the published power outputs of the turbines -difficult to do because of different units used etc. Just a quick glance at this graph shows that there are really big differences in the performances of the rival turbines.
http://www.bettergeneration.co.uk/generate-energy/comparing-the-performance-of-small-wind-turbines.html

Any comments appreciated!

Cheers

Toby

  • 85.
  • At 12:26 PM on 01 Dec 2006,
  • Spartacus wrote:

Dave#75: At last - some data! Where can I find this survey of which you speak?

By the way, I don't agree with the numbers at the end of your post.

Energywatch puts average UK domestic electricity demand at 3,300 kWh/year, so a 2.5 m2 turbine generating 860 kWh/year/m2 would produce 2,150 kWh/year, or approximately 65% of average demand.

Where does your 10,000 kWh/year figure come from?

  • 86.
  • At 12:27 PM on 01 Dec 2006,
  • Jenny Swainston wrote:

I think your article misses the point of wind entirely, and does not take into account the differences of wind available across the country.

Wind a a major feature of life in the West of the UK - not so in the East as the prevailing winds have died by then. So if you live West of Swindon you will probably have higher averages than in London.

Also, I agree that 1 Kw is a little small, I'd prefer to see 3 Kw being sold in B&Q. Then if you do have the required wind it will prvide a significant proportion of your supply. And it is regular and its free.

For me if there was a major disaster wind would provide me (I live out West) with most of my requirement most of the time from a 3 Kw turbine. I'd have to watch TV useage, but fridges and freezers would be OK as would be ligting. - What more do we really need if push comes to it?

So stop being London and S E Centric, we are not all interested in 24 video stream to every new type of device which has far more effect in manufacturing terms than a few highly specialised wind turbines, especially if the are produced in the EU and not in China or India or somewhere where the pay is poor and the environmental legilation hasn't been even thought about yet!

  • 87.
  • At 12:28 PM on 01 Dec 2006,
  • Tamsin wrote:

Roger Lovejoy - where did you find PV cells at this price?

"2 x £300 about 1 sq.metre."

I'd love to know as I thought the minimum spend was about £2000 (including grants).

  • 88.
  • At 12:30 PM on 01 Dec 2006,
  • John H wrote:

A number of things are important about this:
- They are now readily available, which will promote competition and hence efficieny/improvement, so costs to install should fall, while power output will increase
- Some people are happy to install one just to help the environment - its not just about the cost. Although small, every little can help
- A combined approach will benefit the country, ie, if all houses had wind and solar mixes to support power consumption, we would probably be able to switch off quite a few power stations

All points need to be weighed up, not just £/power and my house isn't windy enough.

John H

  • 89.
  • At 12:31 PM on 01 Dec 2006,
  • Andrew Lucas wrote:

There was also an article in the magazine 'Building for a Future' which cast doubt on both the Windsave and and Swift products.

However, there is another issue that, as far as I can tell, has not been touched on in this blog. The Windsave turbine does not allow you to sell your surplus back to the grid. I've asked them about this, and have confirmed that this is the case. The result is that if you generate large amounts of energy on a windy night, chances are most of it will dribble away into the local grid unused. This will have a significant impact on payback times.

Personally, I'm still interested in the general concept, but am waiting for domestic turbines to be exempt from planning permission, as may happen in Wales next year. I'm also looking at a much smaller model, the Stealthgen D400, originally designed for yachts. It won't generate as much, but is silent, works at low wind speeds and won't pull the wall off my house.

However, there are quicker and easier ways to do your bit for the planet. Eighteen months ago, we started monitoring our electricity use daily (it's a hobby. I have two small children and don't get out much!!!). Anyway, we found that simply replacing our old fridge and freezers with a single large model, as energy efficient as we could afford, has knocked more than 10% off our energy usage. If you're considering microgeneration, ask yourself if you've cut down on your energy usage as much as possible by less glamorous methods first. For the energy you do use, why not sign up for a green tariff: we use RSPB energy.

  • 90.
  • At 12:36 PM on 01 Dec 2006,
  • Paul Mursell wrote:

Not only are you correct but most of the wind farms are only marginal at best. I am a professional electrical engineer and have a keen interest in all things 'green' related to electricity.I have often looked at the published data for both wind turbines and wind farms as well as apparently learned papers from proponents of wind power and it is worrying just how much disinformation is published under credible banners. When you consider how much power and influence the various green organisations hold over government we should all be very concerned.

  • 91.
  • At 12:52 PM on 01 Dec 2006,
  • Paul Mursell wrote:

In response to Edward Byard and some other comments about nuclear, gas generation etc. The vast majority of commercial wind farms in the world use what are called asynchronous generators. These are induction machines driven above synchronous speed and derive their magnetising energy from the embedded nuclear, gas etc generation. What this means is that; if you turn off all the conventional power stations you get no electricity from your wind farms. I have seen this magnetising energy referred to as free energy in a lot of papers by proponents of wind energy but this is not true. In order for the generators to turn they have to burn fuel and while they are producing magnetising current they are not producing any real power for the likes of you and I to use. If you then look at the part load performance of a typical cogeneration plant or normal coal plant it quickly becomes obvious that a system using mixed wind and conventional produces more CO2 than conventional only (if the supply and demand are properly matched). If on the other hand you size your conventional plant to only produce the magnetising energy you have insufficient capacity when the wind stops blowing. Wind started out as a good idea and got hijacked by commercial and business interests who needed their returns in 3 to 5 years. It is a sad thing that the environmental lobby are to ignorant or to morally corrupt to recognise this and stop supporting it in its current guise.

  • 92.
  • At 01:07 PM on 01 Dec 2006,
  • Sanjay Patel wrote:

Congratulations. You've hit the point with your calculations which is: How much energy does this things take to make vs. how much energy is it likely to save and also cost to dispose. This would be a fundamental shift in thinking if we can achieve it.

This shift needs to understand that buying more and more stuff eco-friendly or not isn't the answer.

The first step is reduce reduce reduce your use. There is a phenomenal amount of energy to be saved by doing this. More than by buying a turbine.

And when society is actively doing this we'll know just how much energy we need to produce using whatever eco-friendly means are in fashion.

  • 93.
  • At 01:22 PM on 01 Dec 2006,
  • Colin Greenall wrote:

Small wind turbines are good for topping up batteries. That's all. Buy a lot of heavy duty batteries and run your house from low volt systems and a solid state inverter for 240 volt needs. You can get these inverters for cars from 100 watt upwards. Convert one of those to run your minor electrical systems, lights, pump and electrics for gas boilers. Biggest need is the fridge and freezer. Trouble is, there's always a balance between carbon output and manufacturing, i,e. large batteries. The only real heavy duty free energy available is water driven generators, but look at the work in a dam! Where does it stop?

  • 94.
  • At 01:29 PM on 01 Dec 2006,
  • John Bone wrote:

Well, since 1986 I have never had any non-low energy bulbs in any of the houses that I have lived in.

In the first house, (1986) this meant that I purchased 15 "philips" 25watt blubs, and removed 11 x 100 watt incandesent lamps, and 4 x 120 watt blubs. This reduced the lighting load from 1.58Kw to 375 watts (0.375Kw).
When I sold that house in 2004 I still had six of the orginal phillips lamps working! I have replaced the others as they died a flickring death.

Over the 18 years, the energy saved (assuming a average 4 hours of use per day, allowing for summer/winder daylight variations) is a woping 31,668 KWh. Phew!

Reduce demand first as that automattically reduces the carbon production of your household.

JSB, MBEng, BSc Hons

What a fantastic response. Clearly I am not the only person to be interested in the physics of wind turbines. But I have to agree with Chris (#5) that I have been a little too harsh on small turbines.

Just as the cube rule says that energy output falls disproportionately as the wind drops, it also says that as the wind speed increases power output will rise disproportionately. The average wind speed at my house may be 4-5m/s but to calculate the actual power output you need to know the profile of the wind.

If - and this is not my experience - most days the wind is very low but when it blows it blows hard then I may generate significant power even from a small turbine.

There are two problems with this. The first is that turbines don't cope well with gusty wind as Les Upchurch (#48) points out.

A few months ago I spoke to one Londoner (there aren't many out there) who's actually had a small turbine installed. He'd had no usable power whatsoever in the first months and reckoned this was because the inverter couldn't handle the turbulent winds around his home.

The second point is that most small turbines are not designed to handle high winds. Patrick Calthorp (#22)cites Windsave's figures which show that the turbine cuts out above 14.5m/s (and will only begin to turn between speeds of 3.5-5m/s).

I am sorry to say that, like most of you, I'll need a lot of persuading to change my mind that small turbines are simply not appropriate for most homes.

  • 96.
  • At 01:37 PM on 01 Dec 2006,
  • Guy Bryan-Brown wrote:

I was recently going to go ahead with a turbine but got cold feet and bought a PC interfaced anemometer instead. So far my logged data suggests that a 1kW turbine would generate only 30 pence electricity per week despite my house being at the top of a southerley facing hill. I have looked at the 'Betz law' used to design current turbines and am unhappy with it. The dangerous assumption in this derivation is the swept area of the turbine, which becomes inaccurate at low speeds due to the low fill factor of the blades. As a keen sailor, I know that you can still get loads of energy out of low wind speeds simply put putting up a larger sail area and also adding extra shape (curve) to the sails to generate maximum lift. I think that turbine designers and the scientists who advise the government need to get out more.
ps. I am a professional physisist with 20 years experience and I sail to a semi-professional standard.

  • 97.
  • At 01:39 PM on 01 Dec 2006,
  • Andy wrote:

Andrew#89, In replacing your fridge/freezer to make a 10% energy saving, was this at the end of the existing appliances life? Otherwise you need to factor in the energy cost of manufacturing (&transporting) your new white goods

  • 98.
  • At 01:44 PM on 01 Dec 2006,
  • Darren wrote:

From reading the postings above, I have the feeling that the majority of people don't want to give up their use-use-use policy when it comes to energy. I'm building a low speed high output (high output for me) wind-turbine at the moment, and looking for existing ways to increase it's output, as well as other forms of energy collection such as solar heating and solar power to run in conjunction with the turbine. If you buy an off-the shelf system, it will never provide you with what the manufacturer claims unless your in the ideal place (i.e. on top of a mountain etc). Unless we start using less energy, and start looking at providing energy ourselves on a location by location basis, all we'll end up with is ever increasing energy bills, and a climate that would see my kids never being to take a two week holiday anywhere outside of the country. Maybe it's time for us to start looking at what we want and how we want to get it, and then doing something about it rather than standing around saying 'well it's not viable because the wind only blows from the east in the morning'. Sorry for being cynical, but after building a small test turbine (thanks to Hugh Piggott and OtherPower.com) it does look (during its initial testing period) a very viable alternative providing it's coupled up with other devices such as solar to cut the amount of power I and my family use in our home that is produced from coal/gas etc. And if it means that if one of our kids leaves a light on over night (like they all do at times) and the next morning they have to get up in the dark, then after a while they will learn to conserve energy just like the rest of us. If you’re really looking at alternative energy then don’t take sales-men’s words, investigate it properly, and check, check and check again before making an investment. Before I go, I’m not counting the costs of the manufacturing process for my turbine, as it’s for the best part being built from sustainable materials, or recycled / reclaimed parts – I.E. the washing machine that just gave up the ghost after 10 years of service as I’m looking for an alternative to buying one which would cost around £1400 before being fitted.

  • 99.
  • At 01:58 PM on 01 Dec 2006,
  • John wrote:

Come on folks lets get real here.
All I have seen is how much it cost, money money money how greedy we are! If your microwave goes out what do you do, chunk it out the window and go buy another, what about you computer, chunk it to, what about your car same thing CHUNK IT. We have no problems spending our money on material things to make us more Cozy in our lifestyle. WHY cant we as a people make a choice now that we want clean water and air for the future of mankind, my kids, your kids, our grandkids. You have a choice to make is it just about ME or can I think about the future of this planet for a change (remember we dont have any other place to go as of yet) Have you switched your old incandescant bulbs for energy efficent bulbs yet? Probably not because it doesnt fit in with your DECOR, but look at how much energy you will be saving. You may not see you bill drop that much but if everyone did it look at how much savings the power company could make, how much smog wouldnt be going into the air,and how cleaner the air would be. Granted what you yourself do probably want make much of a difference but what if we all did it then we could make a difference. Every wind turbine every solar cell everything we do to reduce the power companys grip on us will make a difference, maybe not stop them all together but get them down to where they dont make a difference. The same thing with cars, we can send spacecraft to the outer reaches of the universe, but we cant get a car that doesnt pollute,come on lets get real. They have the know how but why should they do it, they own stock in the oil companies so why should they want to cut back, (oh yeah we come back to the MONEY thing again) and if they invent something that we are not dependent on them for, I know they lose again (see how greedy this world has become) we cant have clean air and water because of the greed. The very thing that allows US to be who we are (HUMANS) we are destroying because of greed.
Come on folks lets all make a difference in our lives, lets forget about the cost involved or pretty soon it want make a difference, lets all do what little we can in even the smallest way, switch to more energy efficent bulbs, turn off lights when not in use, turn everything off when not in use, so it takes a minute more for your computer to come on. SO what we are in to much of a hurry as it is, slow down and enjoy your life, even if you cant get a good breath of air or a clean glass of water to cool off with.
I know you all are going to be talking about the crazy story you read, do me a favor tell other people about it and maybe someone will go out and buy a new light bulb and do a little part to help all of us live a little longer on this wonderful mother earth we have.
Thanks
JOHN

  • 100.
  • At 02:26 PM on 01 Dec 2006,
  • Dustin wrote:

john wrote:
I also wondered what happened to the electric meter when a gale blowing in the middle of the night was producing more power than being consumed. I assume that the power goes into th grid, but does the meter go backwards???


you can have installed an extra meter to sell back to the grid your over production, This I believe a lower rate than you would buy fromt he grid.

I myself have been looking at renewable techs, but have decided for my needs solar and windpower are not fully fit for the purpose, I have instead been looking at CHP units (combined heat and power) these unit would provide hot water and heating for my property and at the same time generate power. The suplus power beign sold back to the grid and would most likely be at peak times. The CHP unit I am looking at I am hoping to run on bio gas if i can find a supplier of it.

  • 101.
  • At 02:50 PM on 01 Dec 2006,
  • Alex wrote:

Your maths are spot on. The future for wind-generated electricity is large-scale wind farms, distributed across the existing national grid. This is the only way the figures stack up. By the way, like several other commentators on this list, I am a graduate engineer, so I am properly qualified to comment on your calculation.

The REAL answer is to reduce our power consumption. We are barely starting to do this, and our government is relying on economics to drive people to do this. My worry is whether this approach alone will make a big enough difference fast enough. I would prefer to see more lead from government in this.

Also see post nbr 6.
Supposing your average power output is as low as 25W, then your yearly available power is still 219KWh (25W times 24 hours in a day times 365 days in a year). Not bad, if you could store this energy for later use. According to post nr 6 this available power is probably more.
Now suppose that you use this energy to break up water into O2 and H2 by electrolyses. Then you could store the H2 and burn it when you need energy and/or warmth. Any other means of storing energy will do also.

  • 103.
  • At 03:32 PM on 01 Dec 2006,
  • mike becker wrote:

I think you have correctly identifed the major limitation of a wind turbine. Wind speed is unreliable and the cost of storing or exporting any energy generated is also significant. A solar photovoltaic panel is also very inefficient - typically 15%.
Anyone wanting to capture free energy in an efficient, clean, and trouble-free manner should consider solar water heating. You can capture several hundred watts per m2 which will noticeably reduce your energy consumption. The installation will work with most hot-water systems including combi boilers and will give many years of trouble free service

  • 104.
  • At 03:47 PM on 01 Dec 2006,
  • themosthandsomemanever1 wrote:

windgenerator plus battery charger plus diode lighting = success...
windgenerator plus battery charger plus compressed air powered car = success... i think some people dont want design for the REAL world. Namely those with financial interests in maintaining pollution levels and oil prices... How big is the lobby against design for the real world in terms of money and actual workforce lobbying members of parliament?

  • 105.
  • At 04:22 PM on 01 Dec 2006,
  • mole wrote:

Just for information, both the Scottish Executive and DCLG have commissioned work on micro generation and revisions to planning rules (specifically the GPDO). I have seen both reports, which are likely to be made public sometime early in 2007.

There is a clear political imperative to make it easier for people to install micro generation technologies if they so desire. Removing the need for planning permission in *some* cases would help improve the economics. Most people seem to forget that applying for planning permission also adds to the cost of installing a micro generation technology.

I have heard wind industry people say that *most* houses will not be suitable for a turbine, either because it isnt windy enough or because the structure of the building isnt suitable. There appear to be fewer eligibility difficulties with solar (hot water or PV), CHP, heat pumps (air, water, ground) or biomass.

Given that a significant proportion of the energy we consume is used for heating (water, cooking and/or space) then it seems clear that focussing simply on things which generate electricity (whether micro turbines or nuclear power stations) only addresses part of the problem.

  • 106.
  • At 04:36 PM on 01 Dec 2006,
  • greengal wrote:

mind you, at least windsave have stopped you from installing something that they dont think is worthwhile. it might make you feel stupid, but wouldnt you be more cross if you/they had gone ahead and you hadnt generated any power.

perhaps you should ask david cameron how much energy he's generating from his.

btw, chimneys are - i'm told - NOT very good structures for wind turbines. chimneys are good at transmitting vibrations (bad) and sound (also bad)...

another small point, solar PV arrays in the UK work on diffuse light rather than direct sun, so they generate power even on cloudy days (and even in Scotland). admittedly more light = more power, but i dont think it's only cornwall where they are worthwhile (depends on your criteria I guess).

  • 107.
  • At 05:12 PM on 01 Dec 2006,
  • Matthew wrote:

Reply to Greengal.

It is true that solar PV works anywhere, but due to sunlight maps etc it is obvious that there is a far greater potential resource for solar PV in Cornwall than anywhere else. Also with Cornwall being further south the sun is stronger=more potential power.

  • 108.
  • At 05:17 PM on 01 Dec 2006,
  • R Mills wrote:

Good point - wind turbines are becoming a buzz word at the moment which is a bit of a worry. They can work very well when designed correctly and positioned well (ie wind farms that are on high ground or costal fronts), but dismally otherwise.

Perhaps more emphasis should be placed on cutting heating costs with the use of solar collectors. Heating a house requires only 'low grade' energy if it is efficiently designed, which these collectors are ideally suited for. The base heating load can often be met, leaving only small volumes of water (for domestic activities - showers...) to be heated using gas etc.

It strikes me that low grade energy is always going to be easier and cheaper to install and extract for local (ie single house) applications, whilst higher grade energy is best performed on a larger scale at specific sites which are designed to maximise efficiency (e.g. wind farms). Individual turbines are probably not the way forward, particularly if the financial outlay prevents the owner from taking other (potentially more effective) measures to reduce their 'carbon footprint'.

  • 109.
  • At 05:22 PM on 01 Dec 2006,
  • Peter wrote:

What if you had more than one turbine on your roof? Would that help? Would the equation be: Power in watts = (collection area in square feet) x (wind speed)^3 x (0.0054) x (number of turbines on your roof)?

  • 110.
  • At 06:58 PM on 01 Dec 2006,
  • Martyn wrote:

I don't argue with the maths, that has been well covered, and I accept their limts. But I do have two worries that caution against completely rejecting these turbines.

First is the experience that when householders start generating electricity, it has an impact on their energy use. Energy stops being meaningless stuff that comes from a wire or a pipe and instead is something you can "see" being generated. It would be great if we could encourage people to stop wasting energy while investing in more efficient generation (like shares in an offshore windfarm or something). But people like to have something to show for their money...we are all flawed.

Second, I think it is reasonable to make a decision to spend more on a less efficient way of saving energy if it avoids something else we don;t like. So if domestic wind turbines are less effective than big windfarms, but less visually intrusive and don't spoil beauty spots, I'm not too hung up about doing the less efficient thing. The extra money required is actually being spent to preserve views - not on climate change and we shouldn;t confuse the two.

Finally, maybe the main benefit of these devices is that people spend money on them instead of the latest plasma screen, extra holiday, or other energy guzzling status symbol. They might not generate as much as hoped - but they may stop the using of extra energy. I'm worried that fashionable consumption is probably not the long-term way to tackle climate change - but if gives us a short term boost then great!

  • 111.
  • At 07:13 PM on 01 Dec 2006,
  • Nigel wrote:

If the objective is to making us all aware then is being achieved. For the answer to global warming etc, take one of the (few) free tours around the Culham Laboratory in Oxfordshire. I visited recently to see what was happening on safe fusion power expecting to hear lots of ifs, buts, maybes and breakthroughs needed etc. But no, a group of international ordinary looking people are designing the first commercial fusion power station. Estimated on line in 30 to 40 years. They have solved the 100 million degrees bit and are getting down to detailed design. The fuel is Sea Water. The waste products are minimal. The CO2 produced is zero. The radioactive risk minimal as the raw material is not radioactive.

The future is fusion, the present, well lets do everything we can to get to there still alive.

  • 112.
  • At 07:18 PM on 01 Dec 2006,
  • Charles Castle wrote:

The main issue surely is that apart from a vastly overdue need to dramatically reduce consumption we need to actively build larger turbines which actually dont make much noise - i ve stopped to listen -and stop complaining about them in our back yard

  • 113.
  • At 07:47 PM on 01 Dec 2006,
  • peter cropper wrote:

I don't think anyone has mentioned that planning permission
may well be required for these installations.Also I wonder if building regulation approval will
be needed?
You will need to pay £120 for planning permission+a lot more
for building regs approval.
This would push the cost up towards
£2000 and so you would never recover the installation cost over the 10 year product life span unless the cost of
electricity shoots up.
Another point to watch for is that when B+Q installed a new gas fire
for me they charged a £40 survey fee
upfront which was recoverable only if you went ahead with the purchase.
What is the arrangement with the
wind turbine survey?

  • 114.
  • At 07:50 PM on 01 Dec 2006,
  • chris isles wrote:

with regard to windsave's BnQ deal and cost recovery times, the information leaflet states that the life expectancy of these turbines is tenyears and less in "hostile" conditions e.g salty

  • 115.
  • At 08:05 PM on 01 Dec 2006,
  • Sam Kleeman wrote:

Nuclear is the future. Forget about these stupid wind turbines and solar power. There is no way whatsoever that these small insignificant power generation systems are going provide even a nothingth of our power. I do not think these people at the Energy Savings Coucil realise how much energy we use and that with our increasing population more energy will be used. So we need more power that does'nt rely on something we can't control.

  • 116.
  • At 08:05 PM on 01 Dec 2006,
  • peter cropper wrote:

Hello again,
Another point I didn't mention is
does the equipment need maintainence and servicing ?
As they will be on the gable
end on top of your roof it won't be easy.
I doubt that they will last for ten years with no attention to the
moving parts especially up on your roof+so do we also have to add maintainence costs into the equation?
peter

  • 117.
  • At 08:30 PM on 01 Dec 2006,
  • Tim wrote:

I work in a turbomachinery lab. We worked out that because of the fundamental laws of power conversion that you describe, a domestic wind turbine would struggle to generate more than 8 watts on average. Which is an irrelevantly small amount of power.

Worse than this, it represents a dis-benefit to society because of the waste of materials in construction.

There is nothing wrong with distributed power generation. However, it's strength seems likely to be when groups of people do something large together, rather than everyone 'doing their little bit' and in the process actually doing nothing useful.

  • 118.
  • At 08:38 PM on 01 Dec 2006,
  • Jim wrote:

Only real data from real tests will resolve this. Try this site, but you may have to wait awhile for the results.

http://www.warwickwindtrials.org.uk/index.html

  • 119.
  • At 08:39 PM on 01 Dec 2006,
  • Nayan Ashra wrote:

Hmm, your figures look good, and I think many people already knew that wind turbines are incredibly useless, unless of course you live on top of a mountain.

The real question is why the party is promoting wind turbines over solar power, new solar panels can reach efficiency of nearly 40%, it's true they do not come cheap, but recent activity by Google and the like should have propelled solar power to the front of the debate, of course, there would be no practical way to tax the usage of solar panels, and it is proven that if the roof of your house is more than half covered with solar panels, your power consumption will reduce to nil or near enough.

  • 120.
  • At 08:42 PM on 01 Dec 2006,
  • Andy wrote:

We are living in a world where energy is cheap and so are all goods and products (China) because of that. Even if it does not make financial sense to gear up for local energy production now it will soon when the price of energy rises fast and the numbers add up but the products which can make a difference have doubled and trebled in price. We should be sorting this out now while we are rich enough to.

  • 121.
  • At 09:28 PM on 01 Dec 2006,
  • John Wilkins wrote:

obviously Windsave have put him in a spot, but I think for the sake of the show he should still get a windmill, or at least visit houses that have them installed.

They are one of the things that have caught the public imagination, and if they do work then it would be negligent to not have them as part of the experiment.

He has already been wrongly told he couldn't have cavity insulation ; a basic error. Numbered valves on radiators do save money. The 'co2' expert has a ridiculous way of judging peoples' co2 emissions (he includes all the indirect forms of co2 that he can't do much about. instead of saving 30% emission, I would put him at 80%), and as people have said, most of the electricity companies are misleading the public when they switch to a green tariff (regards carbon trading rules). Is this programme a serious attempt at checking out green energy or is a programme for the basic British tradition of negative naysayers putting people off even trying ?

It's sad that windsave (B&Q suppliers) have pulled out, probably due to fear of bad publicity, but I still feel it's important for viewers to see how a windmill goes for him. It does seem like his area might be not windy enough, but we don't know until he tries.

Brian Wilson (former energy minister ?) has a windmill on his house.

  • 122.
  • At 11:29 PM on 01 Dec 2006,
  • chris isles wrote:

i agree, ethical man should get some sort of wind generated power. I am looking at various ways of reducing my energy consumption, and living atop a very big hill in cumbria wind turbines seem a possible solution. however i do remain very sceptical and would be interested to know one way or t'other the savings or not of domestic wind power.

Hmm... Average power output?

Assuming that the windspeed is normally distributed (a normal distribution probably isn't very good, but: it's got a peak in the middle, it tails off at either end, and it's (relatively) easily integrable)...

You'll need a spreadsheet to work this out (actually, you don't, but it's easier)... This was written in Excel... Google have a free one at docs.google.com, but it *appears* to lack the error function (erf), which you need to integrate the normal function...

Type this into cell B2:
=($C$1*SQRT($C$2)*($C$1^2 + 3*$C$2)*SQRT(2*PI()))/ 2

Type this into cell B3:
=(-2*$C$2*($C$1^2 + 2*$C$2)*EXP(-($C$1^2)/(2*$C$2)) - $C$1*SQRT($C$2)*($C$1^2 + 3*$C$2)*SQRT(2*PI())* ERF(($C$1)/(SQRT(2)*SQRT($C$2))))/ 2

Type this into cell B4:
=(B2-B3)*$C$3*0.0054

In cell C1 type the average wind speed

In cell C2 type the variance of the wind speed (the variance of the wind speed is the square of the standard-deviation---or expected variation about the mean---of the wind speed)

In cell C3 type the collection area of the turbine in square feet

In cell B4 you should now have the expected (mean) power output of the turbine... I think.

As an example, an estimated mean windspeed of 8 (whatever units they are), and a variance in the windspeed of 16 (again, whatever units they are) gives an expected power output of 430 W.

PS.
What is the windspeed measured in? And what is the significance of 0.0054?

Sorry, this is completely irrelevant, but I was bored.

  • 124.
  • At 08:11 AM on 02 Dec 2006,
  • Andrew Lucas wrote:

Just in reply to post 97, and the comment on my post 89, the fridges weren't at the end of their life, but they were pretty old. We didn't want to wait until they failed totally before replacing them. The point I'm trying to make is that if you keep carbon in mind when your making purchases for your house, you can start to make a difference.

But Andy, you're so right. Not only should I have considered the energy cost of making and transporting the new fridge; but there's the cost of building and lighting the store in which I bought it; the cost of travelling to the store; the travel costs of the nice man who sold it to me: the energy cost of the industrial estate on which the store stands; the energy I used surfing the net to find the best model in my price range; the energy I'm wasting now replying to you about it; the list goes on.

I get so annoyed by comments like this, because they are so disingenuous. What they say is, "Look, I really can't be bothered to change my lifestyle, so I'm going to hide behind all this guff and look as if I'm a really deep, holistic thinker into the bargain. In the meantime, I'll carry on consuming."

When it comes to the environment, I'm a great beliver in saying that 'it is better to light a candle than to curse the darkness'. For that reason, I've got a lot of time for the sentiment behind posting 99.

  • 125.
  • At 08:28 AM on 02 Dec 2006,
  • michael denton wrote:

It is probably true that the CO2 input to make a small wind turbine will never be recouped in savings during its expected lifetime. However, my view is, do you want electricity or not? When the juice is no longer available because gas, oil & coal has run out where do you get your electricity from??...wind, PV or hydro!

  • 126.
  • At 08:56 AM on 02 Dec 2006,
  • Norman wrote:

There is a lot of very sensible discussion here about how to properly estimate average energy generation and typical savings over a year or the lifetime of the generator, but none of these seem to take into account the fact that for much of the time, that energy is being generated when there will be no actual demand for it. For example, one assumes the wind turbine is turning at night, when domestic power requirements are at a minimum.

Are these domestic generators supplied with some type of power storage mechanism such as batteries and an inverter, so that none of the power generated is wasted, or am I missing something? If there is no storage system, then presumably most of these annualised power calculations are way out.

If one did produce such a generator, with batteries for example, has anyone thought to factor in the cost of manufacturing these, from an energy perspective and from also the point of view of the material pollution produced both during manufacture and at end of life. Also most rechargeable battery systems that I know of have a limited lifespan and lose energy storage efficiency progressively through their life. I don’t think they would last over the 10 year period used by many of the calculations here.

Perhaps some of these “domestic” turbines are supplied with mini-hydroelectric storage systems, where the excess energy is used to pump water up to a large tank at the top of a pole and there is another water-driven turbine which can recover this stored energy.

Someone please tell me I’ve got this wrong.

At the end of it all, I’m sorry to say that I think that whatever we do from a renewable energy perspective these are only short term fixes, as none of these appear to have the ability to generate the vast amounts of energy that the ever increasing population of this planet is likely to require in the future and that’s something that never seems to get talked about. Just how many windmills would it take if (even at current population levels) the entire global population used energy at the rate of a “typical” western household…and that’s without considering how many people there will be in 50 years…100 years and so on. Even assuming that a “typical” western household becomes much more energy efficient, the figures do not make pleasant reading.

We need to look to other higher energy-density power generation solutions. Let’s hope that ITER, the new thermonuclear fusion research project, finally gets its act together, proves that thermonuclear fusion power generation is physically practical, commercially feasible and environmentally sound and that in 50 years time we will be running a world hydrogen economy underpinned by that.

Frankly if we don’t, our children and our children’s children are in for a very grim time of it.

it's a total "use it or lose it" system - if you get that windy night when you've switched everything off, any electricity generated will toddle off into the grid - unpaid for!
I'd suggest that they are preying on the public's widespread ignorance on how wind works, a quick visit to http://www.windpower.org/en/tour/wres/index.htm
will help! - have a good read about turbine siting, turbulence and roughness.
Our company sells wind turbines, and we have been driven bonkers by a procession of people who want roof-mounted ones - we have carefully explained the many reasons why they CAN'T work, especially in an urban area.(There is not enough wind have the power removed from it). Our stock answer to anyone wanting wind generation in a town is "If you can get consent for a minimum 30 metre tower, fine, otherwise, forget it!" - and we wouldn't touch a roof or gable mount installation with the proverbial ten-foot bargepole - to my knowledge, neither would any reputable company!

  • 128.
  • At 02:46 PM on 02 Dec 2006,
  • Steve wrote:

If you don't live in a windy place the is no point in having a turbine. You might do better with solar, if you live in a shady place you wont do well with that, the principle is the same. If however you live in a windy spot(open country is best, go for a walk on the hills and see what wind is about) you can easily get 100 watts which over 24 hours is 2400 watts for an hour, enough for a two bar electric fire for an hour or a tank full of hot water and run your house lights as well. The only thing that a small turbine will do for most people is show them how much power they use/waste and hopefully get them to cut down.

  • 129.
  • At 05:11 PM on 02 Dec 2006,
  • Glenn wrote:

This debate is nothing new, just the BBC getting interested for the first time....

I have wind turbines and some solar PV at my house. One turbine is a DIY homebrew machine made from scrap, ok, it's not elegant, though it looks OK, made from a motor from here and some aluminium from somewhere else, in the light wind we get in Cambridge it spins quite a lot of the time, I get about 25W from it at full power, over the course of a week it will happily charge a couple of 12V batteries, something like 7AH, that power gets used to light my garden and my shed - free power from junk, cost me less than £5, so, it has paid for itself.

I also have a 200W turbine, 2m blades, on a 4m pole at the end of the garden, with some clever electronics I can charge 4 12V 110AH batteries quite easily, even in the 4m/s wnd with extra gusts now and again that I get over my garden, that power lights the kitchen, charges my laptop etc.....

There are also a couple of solar PV panels, 25W in total, these overcome the standby power of the inverter and add a little to the batteries if it is not windy.

If you know where to look and like DIY you can make some useable power for only a few quid.

Where is the saving...!

Well, it's not about reducing the bill by 33% or whatever anyone else claims, it about actually coming to terms with what you are using in the first place, change you light bulbs so you can make enough power for them, switch to a laptop, so you can make the power to charge it. Charge you mobile via the sun etc....Other folk make the power for my washing machine and kettle, I can't make that much.

My bill has not been reduced by the renewable kit I have, but I know how much power I use and what I use it for...that is worth a lot.

I have been impressed with the quality of the comments here, balanced and well informed for the most part, and helpful to me.

I agree that the payback period for the Windsave is unpromising, the rated output over-optimistic, and the case for micro generation overstated.

However, I think I might be more careful to switch off un-needed lights if I knew I had spent £1500 on a wind turbine which was generally only producing around 200 watts..

Perhaps the payback time will look rosier when the oil runs out.

  • 131.
  • At 10:59 PM on 02 Dec 2006,
  • paul camilli wrote:

we are familly of 3 living in nw scotland. we have all modern conveniences, tumble dryer, range cooker with electric grill, 2 ovens and a warming oven, etc etc. we use our power sensibly and don't leave anything on standby. AND WE ARE NOT ON THE GRID! we have a proven 2.5kw wind turbine and it supplies 95% of our needs. who says wind power don't work! our back up comes via a diesel genny which uses about 200lts a year £80 (probably about £40 of electric) so please stop telling me it doesn't work, uses more carbon etc etc because it does. it may not solve everything but it will help.

By the sound of it, you live in the country - and likely in a good wind speed area - if it's a Proven, it will have been properly sited by a real turbine company and I'm sure it works very well! The problem is that even good turbines won't work well in an urban environment, unless on a decently tall tower!
I've not knocked wind power in general, I'm a passionate advocate of the technology, but any turbine has to be properly sited to stand a chance of being economic, and unfortunately, that precludes almost all urban sites (unless you can get consent for a very tall mast!)
There is a very simple answer for anyone with doubts - instead of lashing out on a roof-mounted turbine, invest under 150 quid in a wireless weather station - bung the sensors where you'd like the turbine to be, hitch the base station up to your computer, and save the data for several months - then IF it's showing an average of over 5m/s, get the turbine!(but don't hold your breath!)

  • 133.
  • At 12:26 AM on 03 Dec 2006,
  • John Wilkins wrote:

Currys are selling photovoltaic solar panels, which I would consider before thermal solar panels. They possibly make more sense than windpower as a first option for most people, although I can forsee people using both (and maybe thermal solar panels too).

http://www.currys.co.uk/solarpower/faq.html

Personally I think Tony Blair has underestimated micro-energy (or even communal-energy) as a solution to global warming. He is out of step with the public and Cameron has filled the void.

I recharge my AA/AAA batteries with a small solar recharger from Maplins. Most people still buy alkaline and throw them away afterwards. Its easier to cut down than people think, and everyone can join in and feel smug in doing so.

Equiclimate lets you buy CO2 and retire it. Some electricity companies genuinely do the green tariff the way its intended.

  • 134.
  • At 12:29 AM on 03 Dec 2006,
  • John Wilkins wrote:

On the point about selling electricity back to the grid, it is my understanding that most electricity companies will do a deal. The amount sold may well be insignifant (£20 a year or less ?), possibly more with photovoltaic solar panels.

As I understand it, since Windsave and Currys solar panels don't come with batteries, the excess goes back to the grid.

  • 135.
  • At 02:06 AM on 03 Dec 2006,
  • Tony McLoughlin wrote:

Wind Turbines?...In my garden?...Generating free electricity?...What will they think of next? I suppose they'll be telling me to put my hot water tank on the roof of my house!

No thanks! I'll stick to drawing clean nuclear power from the collection of ex-Soviet agents insulating my loft!

  • 136.
  • At 02:46 AM on 03 Dec 2006,
  • Chris Airey wrote:

You are quite right. I live on a reasonably remote and hilly Scottish estate and am a qualified electrical engineer with a long interest in renewables. I carried out an investigation into using the Windsave turbines on all the estate properties and came to the same conclusion as most. a) The best place to mount any turbine is high up. b) The bigger the turbine the better c) No your meter doesn't run backwards at night when you aren't using the power from the turbine
a) Windsave will not allow or supply for your own installation on a pole or tower. b) the turbine is too small to be effective. c)This is referred to as 'slippage' and means the power you aren't using just disappears into the grid.

For my own house working on installing a Windsave on a tower about 100 yards from the house I estimated the usable generation capacity taking into account known wind profile of the site, distance from house (i.e. cable losses) etc. made it completely non-viable. I'd build a big turbine but the RAF and the NIMBY's wont let you.

Now vacuum tube solar heating (not new they've been around for over 20 years, AEC in Wales had one on demo there back then) is a possibility, unfortunately I'd have to cut down the forest shading my house first. Mmmm perhaps not so eco friendly after all....

You really want to save power. Work out a method of ECONOMICALLY insulating the huge stock of solid walled Victorian houses this country has without ripping them completely apart and building a new house inside the old one!

  • 137.
  • At 10:08 AM on 03 Dec 2006,
  • Graham Paterson wrote:

Well done for exposing this eco-con!

  • 138.
  • At 10:14 AM on 03 Dec 2006,
  • Graham wrote:

Playing with "averages" and trying to persuade people that the average power out is proportional to average speed is the real "con".

To do the calculations properly you need to look at the distribution of wind speeds, calculate the frequency at which each speed occurs, and work out the averag power by producing taking account of the cubed factor weighted by the frequency at which a spee occurs.

Just look on some of the more considered web sites to see how the maths should be done, eg http://www.iesd.dmu.ac.uk/wind_energy/wetc132.html#1.3.1.1

  • 139.
  • At 10:15 AM on 03 Dec 2006,
  • richard wrote:

well the government does have its head screwed on... its beginning to invest large ammounts into fusion power generation. Personally i think it should invest more... i also think that if you want to buy a turbine you should instead donate the money to fusion power research. (a turbine wont pay for itself in 10 years... and on average needs mantanence every 3 years)

unfortunately, the green energy lobby is so caught up with its green back to natureness, that it now seems to not like fusion power.
recently greenpeace criticised the governments spending on fusion power and said it would jeperdise wind and solar???? are they mad... with fusion power, solar and wind are needless!

  • 140.
  • At 10:38 AM on 03 Dec 2006,
  • reg bosinquette wrote:

POWER TO THE PEOPLE

The trouble with most approaches to the power problem is that they are based on old technologies. The problem tends not to be examined from the ground up in modern context.
For example ... the Windsave gizmo produces 250 volts because that is how the grid supplies juice to consumers (power over high voltage is less wasteful than low) However on examining the goodies that use power in my house I discover that most use wasteful transformers to reduce this power frm 250v to 12-15v sometimes less. (lighting, TV, computer, phones etc)
How about using the high voltage flavour power (initially) for white goods and heating and then using the low voltage flavour power for all the other stuff. Manufacturers of appliances will even save money as they no longer have to make and ship heavy transformers in every devices.

Taking each appliance individually we can make further reductions in power. For example insulating a house can reduce the power required to heatit ... is obvious, but less obvious is the fact that we could use use the mains water pressure itself (in some areas) to turn the washing machine - mills have done it for centures.

Finally ... distribution of power (and now data for that matter) is based on the fact that its cheaper and safer to manufacture volts in a central location and send the power out to consumers on hi-voltage pylon networks. How wonderful would it be if at least domestic users had our own methods of generating the volts required (large ones and small ones) using SEVERAL methods rather than concentrating on one. EG... When the sun is shining ... solar volts, when the rain comes along - fresh water and hydro-volts ... then the wind - turbine volts again - and so it goes. To back the whole deal up - a SAFE nuclear flat-pack using as yet undeveloped technologies to provide a bit of electrical clout when we need a high power source. Nuclear technologies in the past have had bad press but they have always been large scale. As far as I am aware smaller scale generators were developed for nuclear subs almost half a century ago... perhaps a safe micro solution could be researched in a serious fashion.

I hope this light hearted look at the problem 'generates' some interest and good luck to all the cranks out there like me who would like to help the planet and themselves with some genuinely free power

  • 141.
  • At 04:02 PM on 03 Dec 2006,
  • Lawrence wrote:

A couple of people have stated that there is enough wind energy in the UK to power the whole of Europe (in theory), but what would be the impact to the environment if we were to convert all of this energy into electricity?
Are we simply assuming that converting wind energy will have no environmental impact?
I'm sure the environmental impact will be small, as long as the actual amount of energy converted remains small.

Burning fossil fuels had little environmental impact... until we started doing it on a global scale.

  • 142.
  • At 06:06 PM on 03 Dec 2006,
  • Stewart Rowden wrote:

From everything I have read on here it seems to me that people investing in small wind turbines are wasting their money.

Perhaps it would be better for the government to set up a scheme in which we could all invest. That scheme would build large-scale renewable energy projects that could actually generate electricity at a profit. Anyone who invested would receive a significant discount (relative to their investment)off their electricity bill that would pay for itself within, say, a 5-10 year period.

At the moment it seems to me that the green tariffs being offered by the utilities companies are actually more expensive. If you want most people to invest then those tariffs need to be cheaper than regular tariffs.

If the government did set up such a scheme there would have to be something in legislation ringfencing it to stop it being plundered for other uses ( although I hear a certain potential Primeminister may have been doing that to peoples pension funds so he'd probably tell whoever drafted the legislation to build in some handy loopholes).

  • 143.
  • At 07:41 PM on 03 Dec 2006,
  • Owen McShane wrote:

Wind turbines are all about storage.
I and many others use windmills on our farm properties because they are cheap and reliable and quite and because WATER IS EASY TO STORE.
So it seems to me that the only potential future for windturbines generating electricity is when we can use the power output to say disocciate hygrogen from water which is then used to power up a hygrogen fuel cell.
So it trickle charges when the wind blows. Cars do sit idle for most of most nights.
The technology is not viable at present but if it does become so then we might see micro turbines sprouting over garages but not till then,

  • 144.
  • At 10:59 PM on 03 Dec 2006,
  • PR wrote:

...Wait until the developers move in to your area, bully the locals and the council, build a wind farm in yet another bit of beautiful countryside, probably at the bottom of someone's garden to supply power for distant cities, and take your tax pounds as profit/ subsidy... Profit, not the environment is driving the proliferation of these things. Otherwise, they would be building them in sensible places where no-one is disturbed and where the power can best be distributed...

  • 145.
  • At 04:00 AM on 04 Dec 2006,
  • Bob wrote:

At last, a mainstream article exposing the fallacy of the domestic turbine.

Ye gods, if Ethical Man, with all the resources of the BBC didn't feel able to point out the basic flaws in the economics of micro-turbines ubtik a freebie was withdrawn then what's the point of the programme.

Oh yes......Ethical Man just does what his producers ask.....remember that trip to the Caribbean anyone?

  • 146.
  • At 07:58 AM on 04 Dec 2006,
  • Graham Lyall wrote:

Ref the post at 131,I don't think anyone on here is arguing that Wind Turbines can work, its just the claims being made for turbines in urban areas don't stack up.

Its OK to show dti wind maps showing 5-6m/s but in reality tests have shown (like the one in Warwickshire) that you are unlikely to achieve speeds of much more than 1.6m/s at rooftop level due to turbulance caused by the roof itself and surrounding buildings.

The other thing that concerns me is the effect on the turbine on the structure of the house itself, has anyone done any research in the effect of resonance and vibration caused by such units on bricks & mortar?

Wind turbines are great and can work very well but its all done to Location, Location, Location.

  • 147.
  • At 09:51 AM on 04 Dec 2006,
  • Jock Stewart wrote:

There is another aspect to this whole thing that must be included - the energy required to produce these silly objects.

There is the economical payback period i.e. the amount of time it takes to offset the cost of the device against electricity costs (which the B & Q one won't to in it's own lifetime) but also the carbon costs i.e. how much carbon was produced in making these things and how long will it take to pay that off.

  • 148.
  • At 09:56 AM on 04 Dec 2006,
  • Theo de Bray wrote:

Wind turbines? I agree, unless in an area with plenty of wind a lot of the time, a complete waste of money. Photovoltaics?? Even bigger waste of money. Solar water heating? Realistically, only viable if you can build an efficient system yourself - most people can't. The best option is insulate, insulate, insulate, and USE LESS energy. TdB (Solar water heating engineer).

  • 149.
  • At 12:00 PM on 04 Dec 2006,
  • Dave wrote:

I think you are being a little harsh. Whilst I am a sceptical about most eco ideas I think Windsave are being fair. They saved you a lot of money at the expense of a sale.
It is true that many houses are unsuitable particularly urban houses. However, many rural properties will benefit. If the size of the blades increase too much the increased loading on your chimney may be a costly and financially pointless exercise. Good luck with your next project!

  • 150.
  • At 12:19 PM on 04 Dec 2006,
  • Tom Oldfield wrote:

Are these wind turbines useful - location/location/location. There is plenty of research and scientific study on such devices, and even some real trials.

1) You would not design a turbine to have optimal output at the average wind speed as several posts have hinted at. You must design (optimise) for a wind speed spread expected for a location for a particular overall energy output. For a micro-turbine of about 1-2 kw peak, this is about 12 m/s (about 24 mph). In general, such a turbine will produce about 50-300W power for autumn/winter/spring most days. At 200W power you would achieve about 5 kWh per day or 1.7 mWh / year. The next question - is this amount of energy realised ?

2) There has been a set of 4 trial that have produced approx 1.6 mWh / year for 2 rural and 0.6 mWh / year for 2 urban cited turbines. You can see that the urban is not great - (£0.15/unit * 0.6 * 1000 = £90/year. add £60 ROC payments - only £150/year return on (£1500 - £500-grant) = £1000) This is a 7 year payback on a device with a 10 year MTBF. For urban this gives a payback of 3.3 years for a MTBF of 10 years using the same calculation.

3) So what is a good location. Low turbulence - low drag site. Turbulence is caused by solid object, basically the wind begins to roll over and over along the ground where there are many houses (simplified). You also get shadowing from large buildings. Drag is caused by soft objects - trees - the wind is just slowed as it goes thought the leaves.

4) How does this compare with photovoltaic/solar collector. Hum... In the case of the photovoltaic, the cost is of order £20,000 for a 12kW peak device giving about 3mWh/year in sourthern UK (1000 W/m2 irradation). These is real case numbers again. The MTBF for photovoltaic is 25 year (defined by NASA). There will be drop off in power as the cells delaminate (20%) and brown (10%) over this period, so numbers are approx and an overestimate. £450/year electric with 150 ROC. 50% grant this time (£10,000) giving a payback of 17 years. A recent problem is a shortage of crystalline silicon (think computers - India and China), and so the cost is rising rapidly and there is a long waiting list - forcing up pricies. The above was last year.
Solar collector extracts heat for hot water - I pay £15/quarter for gas heated hot water in my 99% efficient gas boiler, so I pay about £60/year for hot water. These systems cost £3,500 to £6,000 fitted - the B & Q system at £1,500 is not fitted, so it depends what needs doing. Lets take the £3,500 figure with 30% grant and no ROC - cost is £2300 with pay back of 39 years with a MTBF of 15 years.

4.5) Batteries - don't even go this way - these are not green, toxic, high maintance (MTBF = 3 years). Anything with a battery is not green.

5) Green - payback. You may have noticed that I used payback as a definition of "green". Well, most people like a return on their money. Can we estimate green - yes but it is complicated and we need to work out manufacture energy, purification of metals, extraction, energy, transport, and throw-away cost etc. The easiest way for the average person is to assume that someone has to make money for a commercial system, so a guestimate of costs of energy for the life cycle of a device is about 50% of the real cost. This is really approx - but a starting point. (note that photovoltaic is toxic also so throw-away cost may be more significant).
So even if you lose 50% on the investment, you are probably break even on green.

Summary.
Wind-turbine are probably the most green only if put in the right place, and are justifiable from the emperical (real life) figures even when not put in a sensible place. It is most sensible they are used in exposed places. There is also a high risk of a really stupid placement.
photovoltaic are just about green/payback. Notice that the grant for PV is 50% whereas other devices are 30% bringing the payback in line with the guestimate for green cost. More difficult to put in a stupid place, though possible (I have seen a north facing one !)
Solar collect is a hype - very difficult to recover cost or green cost due to small amounts of energy recovered. Heat energy is just not that useful - electricity is very useful.

Sorry about the length - this is the short answer without the scientific justification !

  • 151.
  • At 12:53 PM on 04 Dec 2006,
  • Louise wrote:

So what about the legions of wind farms that are now sprouting up in the countryside?? Are they effective, do they provide enough power to compensate for their manufacture and the other issues associated with location, effects on nature, local residents??

How do the wind turbines compare in the UK with solar panels? Is solar energy more effective or the wind power???

  • 152.
  • At 01:15 PM on 04 Dec 2006,
  • Tom Oldfield wrote:

OK, last post....

Figures for all types of national generation of power result in much quicker payback. Usually about 3-6 months for onshore wind. This is in line with gas/coal - and better than nuclear. Offshore wind is longer payback - about 9 months. The problem with national generation is the transmission loss and ground currents. For coal/gas/nuclear we also have efficiency of only about 36% for the generation(normalised by types and methods). Of course, it does not really matter that solar is only 1-5% effcient, and wind is only 25% efficient - there is not issue with this. So for national wind power (or any national method) it is easy to recover production costs for the materials.

As for location - this is not a scientific issue and I don't feel qualified to comment. I am aware that wind generation is not silent and not discrete and also large scale. PV is not used nationally in this country - it would not be a sensible use of national resources. Though I would note that the national grid (pylons) were put up without any discussion - and these are also large, noisy (corona discharge), and cause bird strike deaths.

Finally - I have no affiliation to any organisation mentioned here, I have only presented in post 149 a scientific discussion on the energy capture by micro-devices. There are other ethical discussion that I cannot comment on - I am sure others are better able to comment on.

  • 153.
  • At 01:58 PM on 04 Dec 2006,
  • Scott wrote:

Wind "farms" are an enormous tax scam.

No conventional power station has ever been able to be closed because of wind energy.

They are an enormous eyesore.

They need to be rebuilt every few years.

They only provide power for 25-33% of the time.

Here in Scotland, to get "green" power from the wind "farms" polluting the Hebrides to the power-hungry cities, plans are afoot to slap a line of 200- foot tall pylons through the Cairngorms National Park.

"...more than a quarter of tourists surveyed by VisitScotland in 2003 said they would avoid parts of the countryside with electricity pylons, mobile phone masts and wind farms."

"Green" my rear end!

If we need extra capacity, let's go via the only carbon-neutral route: Nuclear!

  • 154.
  • At 02:15 PM on 04 Dec 2006,
  • Phil wrote:

I looked into this kind of thing myself. The WindSave rotors are very small indeed and clearly won't produce much power. To meet your full electricity needs you would need one about 3 times greater in diameter with a battery storage facility to store the averaged power to use in the evening when you need it. The WindSave product is a compromise as they realise you aren't going to put a 3m diameter rotor on your house. Probably will just about pay for itself over its lifetime.

My concern over these schemes is that they are not an efficient use of money. You buy a wind-turbine. Maybe it gnerates a reasonable amount of power a lot of the time, but what happens when it doesn't? Then you need power from the grid. If everyone took your approach we would have a dual redundant scheme with everyone having a wind turbine and a grid supplier. But we would take less energy from the grid but the cost of producing that energy would be higher. If we had all simply invested £1500 each in "green" energy for the grid system then we would totally solve the problem without ugly inefficient wind turbines on our houses. Hence I buy my energy from a grid connected green supplier.

Wind turbines that are grid connected make better use of the available energy. They can be put in coastal areas where differences in sea vs. land temperatures always give good strong winds, and since they are distributed over the country if one area is wind free another area will be very windy. Furthermore the transmission companies can plan for times when wind speeds are likely to be low.

Give up on domestic turbines (and solar cells for that matter) and buy your green energy from the grid. These domestic projects are simply capitalising on the individual's frustration at lack of progress on public policy on green energy.

  • 155.
  • At 04:59 PM on 04 Dec 2006,
  • Morgan wrote:

Why is everyone so fixated on economical payback? At the moment I spend (approx) £400 per year on electricity from the grid. Where is the economic payback? When will I break even?

CO2 payback I can understand (i.e the amount of CO2 saved over the life of the turbine being more than the CO2 used during manufacture etc).

Do we want to be green to better the environment, or do we want to pretend to be green to save ourselves some money?

Lets put the price of electricity goes up by 5 or 10 times it's present amount, because suddenly micro turbines will save money and the environment thus making everyone happy.

  • 156.
  • At 06:05 PM on 04 Dec 2006,
  • Paul wrote:

I am trying to track down local people who have installed the Windsave turbine so I can test the noise levels on a windy day.
I spoke to a young assistant in B&Q recently who claimed to have sold the first one in Grimsby. The customer had been in a few times to report on it and had been quite satisfied. They have sold a few more since then so there should be more feedback soon. Overall there must be a good few hundred systems up and running by now.
If the system is not feasible why is the net not flooded with complaints?
Pity they pulled out of the "ethical man" trial.
I cannot see any point in fitting one below the roof line as featured in their advert - too much turbulence surely?
So - let's wait for feedback before knocking it. Remember that this turbine was trialled before being marketed.

  • 157.
  • At 11:04 PM on 04 Dec 2006,
  • Declan Pritchard wrote:

I too have ordered a WS1000 from B&Q, but I live in Anglesey and can reasonably expect at least 2000kWh per year.

Everyone is too ready to condemn what they do not understand. Let's at least give these machines a few months to perform.

If you want to learn more read my small booklet "Save Money and The Planet" or "B&Q wind turbine & other methods to save £2200 per yr" available on ebay.

  • 158.
  • At 11:53 PM on 04 Dec 2006,
  • J M Briscoe wrote:

I notice in the Windsave FAQ one thing that I have always suspected but never seen mentioned in reviews of the system.

If there is a power cut then your house is as dark as the rest of the road despite having spent a few thousand pounds on the wind genator so you still need candles!


MB


"What happens in the event of a power cut?

Our system goes into safe shut-down [compliant with the Engineering Recommendation G83/1] and self starts when the grid supply is restored."

  • 159.
  • At 12:01 PM on 05 Dec 2006,
  • Dave wrote:


So you read this blog and decide that a wind turbine is a waste of time. So instead, you go out and spend your 1500 quid of expendable income on a nice new plasma telly.

1) It will never pay-back
2) It will depreciate very quickly
3) It probably used the same if not more carbon to make it, compared to a small wind turbine
4) It will only ever consume energy throughout its lifetime
4) It probably got flown in from Japan / China using even more carbon.


hmmm............

Dave

  • 160.
  • At 12:55 PM on 05 Dec 2006,
  • Paul wrote:

Regarding Fusion Power (Richard's letter of Dec 3rd)
To quote a recent article in "Nature", "Fusion Power has always been 3 decades away".
If the proposed new project is successful (and it is only a test bed!), it will take at least another decade to get a prototype generating station built. There is no certainty that fusion power can be commercialised within a century from now. This means that fusion is still too far ahead to help us with the real energy gap which is going to be upon us!
To those who ridicule photo-voltaic solar power, there is now more of this installed than nuclear, world wide and it is expanding exponentially. In Europe Germany is far ahead of any other country due to huge incentives to householders and power is "bought back" at a very high rate.

  • 161.
  • At 01:50 PM on 05 Dec 2006,
  • Borge wrote:

These 10 year payback calculations are simply about saving money. But its not about saving money : its about reducing carbon production.

Investing in reducing carbon production is the right approach.

We ought simply to be measuring if the windmill's construction, its erection materials, and transporting it to the site, PRODUCES LESS CARBON than the carbon that would have been produced by a coal-fired power station to supply the electricity that in fact our windmill managed to create.

Its not savings in the pocket: its saving the planet. The same mistake underpinned Ethical man's thinking about installing TRVs. Ethical man thinks more like 'you and yours' man sometimes.

You can get your wind speed figure, for your own postcode, from the DTI website although an 'average' windspeed for a postcode area isn't all that useful.

http://www.dti.gov.uk/energy/sources/renewables/renewables-explained/wind-energy/page27326.html

I worry that if they don't produce savings, today's domestic windmill vendors will end up being categorized alongside double-selling glazemen ... give a bad name to the industry and will snuff out the well-meaning green instincts of early adopters.

Domestic metering really needs to catch up now – what gets measured gets saved.

Gordon (post 7) is on the right track. There has been something really smelly about Government attitudes to making green policies. It appears to want to shrug off responsibility - asking us 'the public' to take initiatives voluntarily. We don't have time. And whats Government for anyway?

  • 162.
  • At 03:06 PM on 05 Dec 2006,
  • david ch wrote:

how do the wind turbine enthusiasts propose to store the energy created at periods of low or no demand to be ready and available for use at the flick of a switch?

use of lead acid batteries not allowed - think of the environmental impact of manufacture ans , worse, disposal.

  • 163.
  • At 03:29 PM on 05 Dec 2006,
  • James Poole wrote:

"Power in watts = (collection area in square feet) x (wind speed)3 x (0.0054)"

Given the rest of the article correctly uses metric units, why do you state this formula in square feet?

James

  • 164.
  • At 07:07 PM on 05 Dec 2006,
  • Tim Fox wrote:

You're right, thanks for the scientific proof. In addition, an article I recently read pointed out that, most houses weren't designed to have a heavy wind turbine on top of them; so not only are you unlikely to recoup the cost of the wind turbine, there's a good chance it will cause structural damage to your home and be a health and safety threat to anyone living locally!

You're right, thanks for the scientific proof. In addition, an article I recently read pointed out that, most houses weren't designed to have a heavy wind turbine on top of them; so not only are you unlikely to recoup the cost of the wind turbine, there's a good chance it will cause structural damage to your home and be a health and safety threat to anyone living locally!

  • 166.
  • At 11:38 PM on 05 Dec 2006,
  • Gareth Lowe wrote:

I'm surprised no one has mentioned how large scale power generation works. It is very important people understand before they can succesfully evaluate alternative generation methods.

Fuel (coal, oil, gas, nuclear) is burned to raise steam which drives turbine generators which produce electricity for the grid. I expect most people know this already. What they may not realise is what happens when you DON'T use the electricty and this is the key to many of these arguments.

When demand is reduced generator sets are disconnected from the grid but they remain syncronised (eg turning at 3000 rpm) so they can be reconnected as soon as the demand increases. The power stations continue burning fuel and raising steam to turn the turbines and the (no load) generators. Power stations are NOT just turned on and off at will and in fact it takes up to a week to start them up from cold.

So:
1. Power stations are operating all the time, this is why electricity is cheap at night (econonomy 7), they WANT you to use it.

2. Turning off a light bulb does NOT reduce your CO2 output to zero.

3. Unreliable alternative power such as wind (either micro generation or large scale) must have an equivelent amount of spinning backup available from conventional power ready for the second the wind stops blowing.

The last point is the reason wind power has NEVER replaced a single conventional power station.

We can see that from a CO2 perspective things can be counter intuitive, saving money is not the same as reducing CO2.

To reduce your CO2 output you need to take steps to PERMANENTLY reduce your electricty consumption especially at peak times (4pm - 9pm) as this determines how much reserve is required in the grid. You can do this by choosing low power appliances (especially fridges) and using energy saving bulbs.

Reducing consumption is always a better idea than increasing generation.

Hopefully this will help people work out what will reduce CO2 output, what will save money and importantly what will do both.

  • 167.
  • At 11:08 AM on 06 Dec 2006,
  • GMT wrote:

Amidst all this fascinating discussion, there have been various ideas addressing the storage of excess electrical energy produced, but they don't seem to have included the dumping of this excess into hot water.

I think it can't be beyond the wit of a good engineer to devise electronics that, on a millisecond by millisecond basis, sends all energy that's not required for immediate use off to a heater in a tank. Most households have a need for hot water, for washing or space-heating, so it's a convenient way to absorb the excess.

The advantage of this is that you can run your power source (wind or hydro) at its optimum efficiency, and even use the electronics to adjust the running parameters (eg blade angle) of the source to maintain that optimum.

Furthermore, an electric heater will carry on using the available energy however hot the water already is. By contrast, a system that tries to push low-grade heat (eg from a rooftop panel) into high-grade storage, loses effectiveness as the temperature in the high-grade storage rises.

Just a thought from a retired engineer.

I have spent 3 years working in the wind industry and am now an independant renewable energy consultant. While I agree, the likley outputs and national potential from small rooftop wind turbines has been overestimated. There are some technical facts that are being oversimplified in these posts. The variety of windspeeds that go together to make the annual mean windspeed for the national windspeeds are based on simple means. It is good practice for manufacturers to adjust these simple means to the likely spectrum of windspeeds experienced using a windspeed distribution model called the Weibul dustribution. This corrects the basic annual mean wind speed for the likley distributuion of different windspeeds and the energy avaliable. With the windsave turbine at a 5 Meter a Second windspeed site (a typical uk, low windspeed site) the expected annual energy yield, adjusted to the Wiebull distribution, would be 1,139kWhrs a year, about 1/3 of the consumption of a typical house. The problem is that the windflow around and over urban properties is generally turbulent. Most properties are highly unlikley to benefit from a continuous free wind flow, sufficent to get this maximum potential output. This energy yield is also based on the manufacturers data on what their turbine can do at each winspeed, if that is overstated the figures maybe wrong! What we need is some independant monitoring data for the windsave turbine, to test manufacturers claims, something i have been unable to obtain as yet.

  • 169.
  • At 12:09 PM on 06 Dec 2006,
  • Paul wrote:

Windmills heating the water tank:

This is precisely what the Swift turbine does. You can chose whether to store surplus energy in the hot water tank or to use it in other ways. (This is not a recommendation since I do not know enough about the success or otherwise of such installations).
Of course you could always pipe the surplus energy into storage radiators for use the next day. In France, the cheap rate comes through the same meter but on a separate dial, so anything connected gets cheap power when available - ie lunchtimes, evenings and all night. France is 80% nuclear and has very little backup power. People can get very generous grants to install a full system as it helps keep the reactors running at optimum power.
If we had this system here, electricity could be cheaper when the wind blows strongly.

  • 170.
  • At 01:02 PM on 06 Dec 2006,
  • John Atkinson wrote:

Here is a rather different wind turbine that is claimed to produce 50% more power than a bladed design, and in lower wind speeds too:

http://www.windside.com/

  • 171.
  • At 02:08 PM on 06 Dec 2006,
  • Paul wrote:

Re: post 167; Windmills heating the water tank:

This is precisely what one of the approved turbines does. You can chose whether to store surplus energy in the hot water tank or to use it in other ways. (This is not a recommendation since I do not know enough about the success or otherwise of such installations).
Of course you could always pipe the surplus energy into storage radiators for use the next day. In France, the cheap rate comes through the same meter but on a separate dial, so anything connected gets cheap power when available - ie lunchtimes, evenings and all night. France is 80% nuclear and has very little backup power. People can get very generous grants to install a full system as it helps keep the reactors running at optimum power.
If we had this system here, electricity could be cheaper when the wind blows strongly.

  • 172.
  • At 02:40 PM on 06 Dec 2006,
  • David Cleave wrote:

In Post 79, Peter says:

"assuming ~50% efficiency of the ENTIRE process - i.e. bringing the the air to a complete halt and capturing half of that energy"

Peter points out that the power generation of turbines is proportional to the reduction in wind speed they produce.

Therefore, we need to work on turbines that reduce wind speed to the point of reversing its direction. Not only would this mean greater energy production, but also it means that another turbine could be powered using the reversed wind. If wind speed could be reduced so that its magnitude in the other direction is greater than its original magnitude, a single pair of facing turbines could be used to produce a limitless energy supply.

Nobel prize please.

  • 173.
  • At 04:57 PM on 06 Dec 2006,
  • Ian wrote:

The noise levels produced by these turbines haven't been considered by the manufacturers. The B&Q turbine produces a noise level of around 55 dB(A) 5m behind the turbine- Assuming your neighbour's bedroom window is about 10m from the turbine, this equates to a noise level of around 52dB(A). Typical background noise levels in suburban areas are around 35-40dB(A). If this was an industrial source, the relevant British standard (4142) could be used to say that complaints would be 'likely' because of this level of noise. It will be interesting to see what happens if Dave's neighbours start getting kept awake at night!

  • 174.
  • At 05:04 PM on 06 Dec 2006,
  • Neil wrote:

Isn't there supposed to be a way of obtaining more wind energy by means of fixed blades that funnel the wind onto the turbine? I saw this on TV years ago. An array of special blades are arranged like the petals of a flower around the wind turbine. When the fixed blades are orientated in just the right way they 'capture' the wind and focus it onto the turbine, which then spins like fury.
Such a 'wind lens', for want of a better term, might still be undesirably large, but perhaps there is mileage in the fact that it doesn't spin.

  • 175.
  • At 08:55 PM on 06 Dec 2006,
  • David Mitchell wrote:

In his new book HEAT, George Monbiot, one of our canniest writers on green affairs, comes to the same concusion. The claims for micro generation usually say UP TO 30% of your electricity. Therein lies the con. I wrote and thanked Monbiot personally for saving me £1500 as I had planned to buy a Windsave from B&Q. There must be 100 better ways to spend £1500 on energy efficiency the problem is most of them don't make a 'statement' like a cute turbine on your house.

  • 176.
  • At 10:58 PM on 06 Dec 2006,
  • Lyn Jenkins wrote:

A wind turbine with an installed capacity of 1.5kW , will only generate 25 per cent of that on average over a year in even a windy location. That is 0.375kW or a lousy 370 watts. Do you realise that it needs 3.0 kW or 3000 watts to boil an electric kettle or 2.0kW for even a small electric fire? A roof turbine is only going to save on lights, or minor usage.0.37kW is just over 3 x100 watt bulbs. To save that much why not replace six 100 watt bulbs with low energy bulbs , switch the TV and computer off standby and turn the heating of the house down a degree or two?Save on WASTE!! The sheer waste of electricity is phenomenal, yet people think that wind is the answer . It is not. The gales we have had over recent days would rip many a turbine off many a roof. Several turbines in a street could well affect TV reception for some houses.The noise in strong wind with about 10 turbines in a sreet could be far worse than anticipated .......at 4 to 5 am !!!England does not have a clue about wind energy because the BIG turbines are being inflicted on Wales and Scotland. Now Wales is threatened by 14 x600 ft turbines in one site north of Swansea. The Post office Tower is ONLY 580 FEET !! Blackpool Tower is a SMALL 518 FEET!! Nelson's Column is only 158 feet. The BLADES on these new turbines are 220 feet each!! Yet they will not close ONE fossil fuel or nuclear power station due to the vagaries of the wind. Wind turbines produce NOTHING below 10 mph or above 45mph [because the wind GUSTS dangerously]. Those wind speeds occur so often that the 150 ft plus turbines are ON STOP VERY OFTEN [ see metoffice.com/education/archive/uk for proof]!! Wise up!! Wind energy is a FARCE!! ONLY THE NON-TECHNICAL BELIEVE IN WIND ENERGY!! Engineers will tell you it is rubbish. The UK uses 60,000MW at winter peak[ see bmreports.com then bmreporting]. 2000 UK wind turbines desecrating our wild places....not where the chattering classes live...only generate a SPORADIC 390MW , CONTINUOUSLY backed by fossils and nuclear!! GET REAL!!

  • 177.
  • At 11:45 PM on 06 Dec 2006,
  • Gil Evans wrote:

Dear Ian (173)
If you are going to get technical get your facts right. Firstly B&Q info for the turbine states 52dB(A)5m for 7m/s "gusting" and 33 dB(A)5m for 5m/s "gusting". Secondly a wind turbine is a pretty good example of a point source and therefore the noise level decreases at a rate of 6dB per doubling of distance. There is no need to get technical however, if Dave's neighbours and the local council considered the turbine to be a nuisance they could get it abated irrespective of the numerical noise level.

  • 178.
  • At 08:01 AM on 07 Dec 2006,
  • Richard wrote:

I recently saw the display at B&Q for Windsave Turbines and approached them direct for a survey. My house I was told was suitable but they haven't been back since to discuss installation despite ringing them. In the meantime I successfully applied on line for a carbon trust grant on line towards its installation costs. I then made enquiries to my local authority and was told that I would need planning permission at a cost of £135, despite my council saying how much in favour it is of sustainable and renewable energy. At this stage I have given up. An installer that doesn't seem to want my money and a council that wants to take it with neither of them guaranteeing that I'll get what I want, cheap renewable energy!

  • 179.
  • At 12:10 PM on 07 Dec 2006,
  • Robert Campbell wrote:

I considered Windsave in my efforts to reduce the carbon footprint of our home, but after investigating domestic turbines, and reading Heat, I also came to the conclusion that it is a near futile exercise in making one's self feel better. However there are ways to spend a little money and make a decent dent on energy use in the home. We invested in a dozen RF radio controlled plug sockets into which regular multigang power strips are plugged. We keep the remotes handy in most rooms in the house and basically everything is off until it needs to be used. Not only does it cut our electricity useage but it makes things easier to switch on! Brennestuhl in Germany, or Byron in the UK make these and they are a lot more affordable than a turbine especially when despite grants we have some local authorities milking individuals for planning applications of questionable necessity!

  • 180.
  • At 12:59 PM on 07 Dec 2006,
  • Jack wrote:

Worse still, the government is throwing away our money on these devices, through grants from the Energy Saving Trust. To quote from the EST website: "Maximum £1,000 per kW installed, up to a maximum of £5,000 subject to an overall 30% limit of the installed cost (exclusive of VAT.)"


David Cameron has probably done the country a huge disservice, by promoting unproven micro wind turbines over far more tried and tested solar options. As a result, the public is now likelier to buy the message that all micro generation is futile.

  • 182.
  • At 04:32 PM on 07 Dec 2006,
  • Steve Burrows wrote:

Lyn Jenkins says "England does not have a clue about wind energy because the BIG turbines are being inflicted on Wales and Scotland. Now Wales is threatened by 14 x600 ft turbines in one site north of Swansea"

Suggest you check out "The London Array" Lyn, all 100 square kM of it.

This was a very interesting article which confirmed my thinking, that using less and wasting none would make a more cost effective contribution than installing an "Im a green statement" wind turbine on the roof. Solar, both heat and electricity, sounds more promising.

  • 183.
  • At 05:08 PM on 07 Dec 2006,
  • Martyn wrote:

So, what do we do? Nothing? That's what it sounds like to me. If someone is naive enough to think they can put up one of these things and have it pay for their electricity bill then they deserve to get ripped off. As for the maths, all very nice but every location is different, the wind is not constant so play with the figures all you like it makes little difference and like most statistics they are utterly useless. The simple fact is this, if 1W is generated by a wind turbine at any given time and there is a 1W load in the house at that time then that is 1W of power that is offset from a green source. We all have a base load folks and that is what you are offsetting against when you install ANY micro renewable. We can all argue about the maths, disadvantages, grants, how rubbish they are, how inefficient they are yawn yawn yawn, but to do that and to do nothing is to miss the point entirely. Unless we start using renewable technology it will never develop and we'll not get anywhere tackling global warming. This technology is a step in the right direction, it does save you money, and it does reduce your CO2 footprint. It's not perfect, but it's better than moaning and doing nowt!

  • 184.
  • At 06:07 PM on 07 Dec 2006,
  • Dewi Sant wrote:

Post 176,

Can I welcome Lyn Jenkins to the site? I wondered how long
it would take for him to appear.

For those of you who have never heard of him, Lyn is one of about half a dozen wind-farm 'full-time objectors'. Most are elderly and are spending their retirement writing obsessively about the subject everywhere and anywhere. This posting will reflect only a tiny fraction of Lyn's output: one local paper prints something by him almost every week (although he has been quiet of late). I suspect he is writing to a newspaper or website somewhere most days, and always on this one subject. Lyn lives nowhere near Swansea, by the way. He is a farmer near Cardigan, 50 miles away.

Quite why he should want us to cut down on energy is a mystery. He
regards climate change as a global conspiracy against Wales, between
green organisations, corrupt politicians and wind farm companies.
Amongst his more bizarre pronouncements is that emergency services will have to stop using helicopters, because they will fly into windfarms and crash. He has also said that he rejects climate change on the grounds that he saw the film 'The Day after Tomorrow' and thought it was
rubbish.

Lyn specialises in dreadful poetry and long streams of conciousness,
much of which is written in capitals. He does this a lot. It makes him look as if he is shouting, which is probably not far from the truth.

  • 185.
  • At 07:24 PM on 07 Dec 2006,
  • Phil Gilbert wrote:

One way of producing more electricity from a small wind turbine would be to attach it to a kite. Kites can travel over twice the windspeed at an angle to the wind producing over ten times the power for the same device at a given windspeed. The kite could be computer controlled. Not really domestic use, but farmers with all their land should be the real micro producers.

  • 186.
  • At 09:21 PM on 07 Dec 2006,
  • Graham Smout wrote:

The windsave gear has never been claimed to be suitable for all locations; average wind speed tables are available on line that will tell you intantly if you have a high enough average wind speed to make the unit worthwhile.

Visit to find data for your area:
(I have minimised it for ease of use)

http://tinyurl.com/hsssc

As for wind energy in general; this quote from the UKWEA may provoke some discusion but it is informed scientific advice
Energy Balance

"The comparison of energy used in manufacture with the energy produced by a power station is known as the 'energy balance'. It can be expressed in terms of energy 'pay back' time, that is the time needed to generate the equivalent amount of energy used in manufacturing the wind turbine or power station.

The average wind farm in the UK will pay back the energy used in its manufacture within three to five months, and over its lifetime a wind turbine will produce over 30 times more energy than was used in its manufacture.

This compares favourably with coal or nuclear power stations, which deliver only a third of the total energy used in construction and fuel supply. So, if fuel is included in the calculation, fossil fuel or nuclear power stations never achieve an energy pay back. Wind energy not only achieves pay back within a few months of installation but does so from a fuel that is free and inexhaustible."

Is this correct? Can any one challenge the above information?

I am currently investigating solartwin solar panels ; http://www.solartwin.com/
as they are a) cheap (£2500) and b) require no complex plumbing. The main drawback seems to be they are not suitable for home with combi boilers; you must have a cylinder based DHW system; either immersion or conventional boiler powered. (which brings me to another point- combi boilers are NOT inherently environmentally friendlier)

The way forward for energy use is complex but quite possible and should be based on high levels of insulation, low energy appliances, and micro power generation; solar photo voltaic, wind and solar radiation are all key to the energy crisis.

MY father has a neighbour in his town in the north east of england who has drilled 300 ft into the bedrock and is using geothermal energy for space heating; pumping down cold water and extracting boiling water.

I have visited a home using 350m of standard cold water pipe to extract goethermal heat via a heat pump; (same priciple as a fridge or dehumidifier) the input is 1 - 2 KW for a 30 + degree rise in the water temp, based on an air to under ground temperature differential of 4 deg. at .5m depth . This can then be used for underfloor heating.

These principles are the way forward; not nuclear which is hideosly expensive; even if it worked which 90% of the time it does not. Also; does anyone ever consider; where does nuclear fuel come from? Is there an unlimited supply? what are the economics; finacial and ecological of mining uranium; What is the carbon footprint of a gram of uranium? It is not zero and is not cancelled out by the power it can produce.

Regards

  • 187.
  • At 07:48 AM on 08 Dec 2006,
  • paul worthington wrote:

Eh?

  • 188.
  • At 07:57 AM on 08 Dec 2006,
  • Dave Heed wrote:

Congratulations - yet another example of negativity towards what will soon become an essential aspect of our lives.

The knockers run down wind power on a larger scale because it will not provide ALL the UK power - same was said for wave power and solar power but they will make their contribution

All of these ideas will provide SOME benefit in teh long term so long as they are not treated in isolation - we have to reduce usage as well- you know all those range rovers in Suburbia - flights overseas for holidays - becasue like it or not the oil WILL run out maybe not in your lifetime but certainly in your kid's - god help us if they are as negative as you lot.

Politics aside think as Camerons wind turbine in the same way as Brad and Angelinas hybread car - maybe not a solution in its self but certainly making these ideas more mainstram and familiar.

  • 189.
  • At 05:32 PM on 08 Dec 2006,
  • steven wrote:

I have solar water heating panels on my roof. They raised the temperature of my cylinder from 28deg to 40 deg 2 days ago, THE 6TH DECEMBER!!!! and I live in the UK!
From March to October they provide ALL my hot water.
Heating water uses huge amounts of electricity/gas, so my carbon ourput is now massively reduced. Even if they only add 2 deg to my cylinder on a dull day, that's 2 degrees less for the gas boiler to do. Get some, they're excellent, I can't see why anyone would disagree.
I am not sure about wind turbines unless they are used to charge batteries. They're a good idea in theory but I'm not rushing out to buy one just yet....

  • 190.
  • At 01:11 PM on 09 Dec 2006,
  • andrew kelsey wrote:

If I were a businessman selling a wind turbine via a national retail chain and the product was technically sound and could be defended I would be defending it on this website and all the others every day. The fact that Windsave seem never to appear speaks volumes to me and is all I need to know on the subject really.

  • 191.
  • At 12:07 AM on 10 Dec 2006,
  • Andrew wrote:

It seems that it's not just domestic wind turbines that have been oversold... Apparently most of the mainland windfarms have been under-performing - see today's news (10 Dec), eg http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2006/12/09/nwind09.xml (did the BBC cover this story? - was on ITV news as well as the Friday/Saturday Telegraph)

  • 192.
  • At 03:56 AM on 10 Dec 2006,
  • Ben wrote:

120 watts is still quite a lot of power on average. Years ago there was a bicycle fixed to a generator instead of a back wheel on display at the science museum and when I was pedalling quite strongly I was generating about 120 watts. Imagine doing that all day!

However what you need is a mixture of electricity sources of which this ingenious little wind turbine is only one. Also consider a photovoltaic array, solar water heating and if allowable, a wood burner.

  • 193.
  • At 07:06 PM on 10 Dec 2006,
  • Frederick Gair wrote:

In commenting about the value of wind turbines, it may help to introduce some perspective if the following thought is noticed.
During the last twelve months, the combined Kwhrs sent out by all the 1700 or so wind machines around the British countryside has not matched the output of a single one of the six conventional coal machines at Drax.

  • 194.
  • At 09:21 PM on 10 Dec 2006,
  • Graham Smout wrote:

re comment 193; I feel thats a spurious argument; If the 1700 or so wind turbines were not there, then extra carbon fueled capacity would have been generated elsewhere. Most probably by gas turbine, as these are the instant on genrator sets. Drax and other coal fired, and nuclear provide the base load supply for the UK. They will for some consderable time. Ultimatley they must be phased out and replaced by a combination of lower demand, and alternative fuel powered geneartor sets.

Here is a vision of the future; you can be cynical if you wish, and dispute the scenario, but it will happen.

Every home and building is, courtesy of initiatives set in motion in 2006 by then chancellor Gordon Brown, carbon nuetral; ie it requires no external overall power, in fact it produces more power overall in a year than it needs. However at night and in the winter, or in poor weather, it produces no power and relies on the grid.

The grid is powered by a combination of:
Wind Turbines
Hydro Schemes
Sea current power; (go to Lynmouth in Devon of you dont know what this is; its not wave or tidal power)
Solar
Waste Incineration Combined heat & power
Micro generation
Instant High load generation powered by biofuel driven Turbines; (bascially Huge jet engines running on biomass fuel driving large genrator sets for backup.)

Its that simple.
All it takes is the will and the cash.
Best Wishes

  • 195.
  • At 09:28 PM on 10 Dec 2006,
  • Graham Smout wrote:

Re comment 193; I feel that’s a spurious argument; if the 1700 or so wind turbines were not there, then extra carbon fuelled capacity would have been generated elsewhere. Most probably by gas turbine, as these are the instant on generator sets. Drax and other coal fired and nuclear provide the base load supply for the UK. They will for some considerable time. Ultimately they must be phased out and replaced by a combination of lower demand, and alternative fuel powered generator sets.

Here is a vision of the future; you can be cynical if you wish, and dispute the scenario, but it will happen.

Every home and building is, courtesy of initiatives set in motion in 2006 by then chancellor Gordon Brown, carbon neutral; i.e. it requires no external overall power, in fact it produces more power overall in a year than it needs. However at night and in the winter, or in poor weather, it produces no power and relies on the grid.

The grid is powered by a combination of:
Wind Turbines
Hydro Schemes
Sea current power; (go to Lynmouth in Devon of you don’t know what this is; its not wave or tidal power)
Solar
Waste Incineration Combined heat & power
Micro generation
Instant High load generation powered by bio fuel driven Turbines; (basically huge jet engines running on biomass fuel driving large generator sets for backup.)

It’s that simple.
All it takes is the will and the cash.
Best Wishes

I agree with most of the previous comments in message 195.
However, Gordon Brown's proposals re carbon zero homes only applies to homes yet to be built. I heard nothing in his speech about increasing the grants for retrofitting micropower systems to existing homes.
I am going ahead with my plans to turn scrap into power. I am collecting defunct microwaves for the magnets and wire. Offcuts of 8 to 12 inch plastic pipe for the blades and offcut marine ply. I have a buggy motor promised for a first effort and will build my own axial generator when I get enough magnets. I need 10 microwaves, which will take about six months to collect.

  • 197.
  • At 02:57 PM on 12 Dec 2006,
  • Ed wrote:

All of these calculations seem to be correct. Last year I was working on a 3m diameter turbine as part of a Physics degree and managed to get 30 Watts at wind speeds of 10m/s, 8 stories up. Residential wind turbines are not economically viable. Wind turbines become economically viable when there is more than one supplying a larger property, a small business for example. People may be interested in the new 42 story Multiplex tower planned for Elephant and Castle by 2014 which has 3 large turbines built into the top which are intended to provide enough power to light the building.

  • 198.
  • At 05:21 PM on 12 Dec 2006,
  • james wrote:

There seems to be rather a lot of speculation about how good , how bad roof mounted wind turbines are.

Key apsects are:-
1. do they generate meaninful energy - answer yes (from personal knowledge on unit on my house (non windsave.)
2. Can this technology be improved and outputs increased- answer yes
3. will costs come down - answer yes

But there is very little quantified information, it is nearly all estimated.

  • 199.
  • At 05:03 PM on 13 Dec 2006,
  • Frederick Gair wrote:

Comment number 194 in response to my original comment Number 193 suggests that my text is a spurious argument.
However, it was not offered as an argument but as an attempt to introduce some perspective.
Despite the many efforts to improve efficiency and insulation, electricity demand in the UK is still rising at an annual rate of about 1.6 percent.
All of the so called renewable initiatives commonly promoted can not meet this increase, let alone replace existing plant.
Nearly all of our current coal fired plant is over forty years old and does not meet EEC requirements. Most of the nuclear plant is due for closure by 2010.
As at present, we need an increase in capacity of about 1300 Mws a year to meet maximum demand, equal to 650 large wind turbines, hopefully subject to wind speeds of 15 metres/ second at peak time. Records show that peak demand invariably happens when wind speeds are low.
If fossil fuel generation of electricity was abandoned in Britain tomorrow, the global emmission saving achieved would have disappeared within twelve months.
The developing world demand is rising at about 4 percent and it seems to me naive to think that by setting an example we can encourage those economies to follow us. As Bjorn Lomborg has said, perhaps our investment in renewal activities might be better directed to preparations to deal with the forcast climate changes. Being on the moral high ground will not stop our feet getting wet if the sea level rises.

  • 200.
  • At 07:24 PM on 13 Dec 2006,
  • Don Curtis wrote:

This whole discussion makes me very angry and reveals the gullibility and lack of education of the great British Public.
There is now hardly a word heard or written about the only feasible and green solution to secure our future energy supplies.
That is of course - nuclear powered electricity generation.

Only a year ago the PM and David Cameron hinted that a nuclear - power programme will be part of the future . All politicians seem now to have dropped the nettle.
I will not labour the tremendous strategic bonus it embodies — the instablity and unfriendly sources of gas or oil.
Who wants to be beholden to Russia or to Iran for ever?

Also, unanswerably telling, is the fact that the sustainability hype is a misnomer. Nuclear is the only true re-usable fuel available in quantity and has no greenhouse emissions.

Waves and wind will never meet more than a minor portion of our needs.

I cannot vote for any party or person
who is so mealy mouthed that they are frightened to even mention the word nuclear-power

  • 201.
  • At 02:44 AM on 14 Dec 2006,
  • themosthandsomemanever1 wrote:

.... In response to post 200.... Uranium supply is limited and the damage from nuclear power unlimited as the death and injury toll only ever increases. The nuclear power stations on the coast are already in the wrong location given sea level rising and rivers in europe were becoming too low and warm this summer to be used for nuclear power station cooling. Nuclear power is a filthy solution to the filthy internal combustion engine and the complete waste of energy of the tumble drier and the light bulb.(post 104)
Basing world economy on ecology is the only way to continue.

I wonder if James in message 198 could tell us something about his roof-mounted turbine?
Is it home-made or purhased and what is its rated power? Also how much power is being generated and how does he utilise this eg when house demands are low and the wind is blowing strongly!
I await with interest the Warwich University study of various roof-mounted generators. You can follow progress at their website:
http://www.warwickwindtrials.org.uk/index.html

  • 203.
  • At 06:38 PM on 14 Dec 2006,
  • Graham Smout wrote:

In reply to no 200: I agree with reply 201, nuclear energy is neither clean nor renewable.
A very intersting article can be found on the World Nuclear association web site which is as follows:
http://www.world-nuclear.org/info/inf10.htm

However it underplays the problems with nuclear fuel and generation of power, while at the same time being very realistic about alternative fuel supplies. The assumption is made that demand for electrical power will continue to be high, which will continue to require high base load power production from sources such as nuclear. If that were the case then I would have no argument with nuclear. The alternative suggestion is that we move awy from centrally grid supplied power and move wholly into microgenertaion and local home produced power.Grid power is a luxury we cannot afford to continue with.

Quite near me, on the North / West yorks border, (and in many other places in the UK) are homes and building with no grid power, relying completely on wind and solar power, with intermittent generator back up, so with development there is no doubt that the future of a non grid conencted world is quite possible. (I might add, the homes with the independent power source are the only ones watching TV when we have power cuts!)

Graham

  • 204.
  • At 05:02 PM on 17 Dec 2006,
  • james wrote:

In Response to 202
The turbine is manufactured by a leading manufacturer and rated at 400W at 16m/s
Over the 3 weeks the turbine has generated 18 kWh (units) grid side.

Taking into account the current inverter which is converting effectively only about 50% of available energy, and has a enetgy consumption , with product development, this become very meaningful free energy.

At times when there is more energy than local demand, the energy not utiised in home is exported to grid, which in essence means next door has it.

  • 205.
  • At 06:35 PM on 17 Dec 2006,
  • Paul wrote:

Re Message 204 regarding an unamed commercial windgenerator.
Good to hear something positive about home micro wind generation.
That's a tidy output you're getting from such a small unit. On the other hand it has been rather windy over the last three weeks. It's still a credit to your machine since winds have been so strong that several lesser machines must have been shut down for their own protection.
A pity that Warwich University couldn't use your installation for their survey. Their first installation is going in a few months time.

meaningful? - 18kw/h in three of the windiest weeks of the year?
Assuming that it blew like that ALL year, we are generating about 60ps worth per week! - £30 a year!
And when precisely has it "paid back" it's financial cost? - 20,30 years?

  • 207.
  • At 10:15 AM on 18 Dec 2006,
  • james wrote:

Re 206
If you read artlicle you would recognise that I have outlined that the technology/inverter needs development, and my property is evaluating this technology with a view to improving it.
The areas where this technology can be improved are known, and lets face it the associated challenges/costs are far lower than putting a man on the mooon. Costs will fall when manufaturing scales increase, which wont happen until technology development takes place. Bearing in mind wholesale energy prices will also rise,a 20/30 year payback could soon become a few years.

Remember - In 1990 a 286 PC with 1MB or RAM and a 20MB hard drive cost £2000. In 2006 a modern PC processor with 500M or RAM and 60GB of hard drive sells for about £400.

  • 208.
  • At 02:05 PM on 18 Dec 2006,
  • james wrote:

Re 207
Martin - I see you are flogging overpriced solar panels at nearly £4/Wp and also micro wind turbines on your website. What is payback of your PV panels at your prices 60 years?

if properly sited, micro turbines can produce meaningful amounts of energy, but that means adhering to all the old classics - clear, non-turbulent airflow - with a good clear fetch - on a tower as high as you can go. This precludes roof-mounting!
All the data we have seen suggests that the windspeed over a roof shown as being the "average" 5.8 m/s on the Noabl database, actually has one of under 2m/s at roof level- 4mph! - at those speeds, there just isn't sufficient power in the wind to be harvested!

In 25 years, a solar panel will probably be producing around 90% of it's original power, and probably good for another 50 years at least!

  • 210.
  • At 10:16 AM on 19 Dec 2006,
  • james wrote:

Re 209
The positioing of wind turbines in exposed open locations is obvious, and obviously performance in these locations will always be better than in built up areas. However I do not concurr with your refernce to the Noabl database, as this guidleine is now accepted as not relevent in this context. Remember the vturbine is not at roof level but 1.5 metres above, so there is also potential for acceleration of wind. I have an NRG anemeometer near mine mine, and am taking a careful log. There are too many experts who simply can not procude any quantified data - I can, and the results are encouraging. But the technology is a couple of years away, and probably ought not be sold in shops yet.

I seem to remember that putting PV in the street under trees to light bus shelters was condemned by the experts, and yet these preconceptions were proven to be weak.

  • 211.
  • At 09:04 PM on 21 Dec 2006,
  • government spin off wrote:

Very good thread indeed !

With regards to these mini turbines in the u.k. I can only see government spin and some dodgy backhanders thrown in.

If every household in the u.k. ordered one, how much energy useage and carbon emissions would result from their manufacture in relation to the energy gained ?

As previously mentioned this is purely a 'safe' goverment spin and the blame for failure can be pointed elsewhere.

Cheap, effective solar panels are the only way forward but the government dont like them because they will lose too much vat !

  • 212.
  • At 10:12 PM on 21 Dec 2006,
  • John B wrote:

I like the idea of renewable energy from a money-saving perspective (I'm not a believer in anthropogenic climate change, although that's not really the argument here)

Looking at claimed savings from domestic wind turbines suggested I would save 25-30% of my electricity bill. I pay about £600 per year for electricity so that makes for a £150-200 annual saving. If it costs me £2500 to buy and install the thing I need 12-16 years before it even pays for itself, and that's assuming it doesn't need any maintenance in that time and of course that the numbers used in the sales pitch aren't even slightly over-optimistic.

So I drew the conclusion that these things are great for being visibly "greener than the Joneses" but offer little practical benefit.

  • 213.
  • At 11:21 PM on 21 Dec 2006,
  • Daniel wrote:

Hi
I just watched your report on the wind turbines. I tohught how very poor the quality of the reporting really was for the BBC's so-called flagship programme. Did you not read the posts 5 and 6 above which both eloquently explained why your calculations were misleading? Given that they were made well beofre the show was aired then I don't understand why you failed to include them. You failed to incorporate the carbon required to make the turbine in the first place and you ended by estimating that a switch to your green energy supplier reduced your footprint by between 5 and 70%! Come on, you can do better than this - or can you? It is a very complicated business to estimate these matters so maybe you should just admit these and withdraw from the debate until you've learnt the science.
As a scientist myself I get very angry by the lazy approach to science reporting in the media in general and Newsnight in particular.
Rant over.

  • 214.
  • At 12:11 AM on 22 Dec 2006,
  • Nigel Reese wrote:

I have looked at ground source heat pumps and solar (hot water and photovoltaic(PV)systems), having quickly dismissed wind turbines as a gimmick. Well done Newsnight for pointing this out. On a scale of cost and payback time solar hot water systems have the edge, PV systems are attractive but horrendously expensive and I am sure the manufacture of polycrystalline silicon is very expensive in energy and chemical terms, so they are not entirely green. Ground source heat pumps might be OK with a new build if designed correctly, but they use electricity which is carbon rich if not nuclear. There is an amazing amount of hoop talked about "green" energy systems. The best way to go green is to insulate the loft, reduce the size of your car and its engine, change as many light bulbs as practicable to energy saving ones (omitting the dreadful LED ones) and turn lights off when you are not in a room etc. Most other options are either too expensive or too expensive and not yet praticable. However, I await developments such as more grants and tax breaks for green choices with interest. At least we are beginning to sit up and take notice about our profligate use of energy.

  • 215.
  • At 12:19 AM on 22 Dec 2006,
  • Gary Bates wrote:

Every little bit helps.

You may be right concerning realistic power limitations of a domestic wind turbine. One of these will not run your sunlamp. But what about background power demand?

Think of all the low power demand from fridges, indicator lights and computers on 'stand by' 24/365.

In one day that 150 watts from wind power can lead to a saving of over 12 millions joules of energy.

Over a whole year that same 150 watts adds up to a staggering 4.7 billion joules.

This is equivalent to 1,314 kWh. See http://www.carbonfootprint.com/calculator.html to see what saving this amounts to in terms of reduced carbon emission.

Over 500 kg by my reckoning. It isn't big league, but every little bit helps.

Cheers,


Gary.

  • 216.
  • At 06:58 AM on 22 Dec 2006,
  • David Stone wrote:

I have another story worth following up on Newsnight, again alternative energy. It is a bit off topic but probably gives an insight into the real Government policy.

I live in Northern Ireland and have a farm. There has been a recent offer of grants to grow willow for alternative power / heat / oil replacement. I have applied with a good economic case, several people willing to change from oil heating to using my willow, an ideal site to grow the trees etc. I was refused as my scheme was "too small to be viable, and the costs are much lower than the other applications"! Almost all the grants were given to two large schemes, and all of the grant money available from the EU was not allocated! (What happens to the rest??). I am still going ahead with growing willow, on a slightly smaller scale due to having to fund it entirely myself, but in a few years expect to be saving at least 10 tonnes of oil per year.

My conclusion is that the Government is not interested in schemes which actually work, only those that can be publicised as doing something big. Those who read the applications have no technical knowlege or interest and so cannot distinguish excessive costs, and even use low cost as a reason to not do anything. Our chance of real fosil fuel reduction is being lost due to stupidity.

I am a Chartered Engineer and have been interested in alternative energy production for at least 20 years. I agree with all the sceptical comments above, it is difficult to make a significant difference as the available energy density is very low on average. BTW don't wait for fusion, it is many decades away, if it can ever be made to work reliably at all. Before that happens a great many people need to rethink the basic physics they think that they are using!

  • 217.
  • At 08:30 AM on 22 Dec 2006,
  • Peter Judge wrote:

Shouldn't we be thinking in terms of generating only 12v electricity using wind power at domestic level, for lighting and some other small electrical appliances. That would mean rewiring houses, but I understand that 12v wind generators have been available for caravans etc.? When the wind is blowing it keeps 12v batteries topped up, which then supply the power to the house. It is just too difficult to generate 240v electricity on a domestic scale.

Better than having wind farms, though; would be to place medium size wind generators, firstly, next to, or on top of, every electricity sub-station, and later, at other convenient locations in every locality/estate/village/town/city

On individual properties, heating can then be supplemented from solar heating panels, and further electricity from solar photovoltaic cells.

  • 218.
  • At 12:10 PM on 22 Dec 2006,
  • Frank Frenz wrote:

Having read and enjoyed the above blog and responses, I was looking forward to last night’s TV segment on wind turbines.

Can I if possible make the following suggestion to future TV segments?

Could you try letting the people you interview speak?


Many thanks


FF

It is very interesting to see what people have put in to their comments about the mathematics. Has anyone considered that in urban areas the more micro turbines that are put up the more energy is taken out of the wind and therefore those who are further down wind will get less energy to turn their micro turbine. For every action there is a consequence!

We are an island nation and there is little mention of wave powered generation of electricity. We have mention of the Bristol Channel barrage which will be ecologically devastating but there are many methods of generating electricity from the waves that constantly pound our shores. These would be invisible from the shore as they lie below the surface and they would remove energy. Instead the focus seems to be on the high visibility wind turbines that blot the landscape.

  • 220.
  • At 03:31 PM on 22 Dec 2006,
  • schober wrote:

what took so long to discover wind power is a joke?
even the professionals can only get 25 - 30% (and thats being generous) yield on installed capacity from an exemplary site near the w coast on top of a hill!!!!!!

see cefn croes wind farm yield
http://www.users.globalnet.co.uk/~hills/cc/recentnews.htm
and details of the farm
http://www.falckrenewables.co.uk/current_projects_details.asp?gid=7
and spreadsheet of yields of all uk wind farms; cefn croes is one of the better ones!!!!!!

  • 221.
  • At 04:25 PM on 22 Dec 2006,
  • Mark K wrote:

Another thing you don’t consider is the safety angle. These machines will frequently be poorly installed and get little or no maintenance. When on breaks up in a gale and launches high velocity scythe blades into an urban neighbourhood a lot of damage is going to get done. People are going to die and, once they have been installed in large numbers, this will become a frequent occurance.

Watt for watt the nuclear power station on the horizon may not be a fashionable but is far less likely to kill your kids.

  • 222.
  • At 05:10 PM on 22 Dec 2006,
  • Ben Pattinson wrote:

I have experienced a simialr frustration. My initial interest was with a system called the "Swift" turbine (1.5KW) which is large in diameter and therefore very efficient, silent etc etc. Then a routine trip to B and Q highlighted the availability of the windsave unit which I have to say looked poor incomparison to the Swift and only 1KW however it was cheaper. I got in touch with Windsave and a surveyor from the "Mark" Group came round and advised the same as you have had, it would not be efficient where I live due to proximity of other houses even though I live on the top of a big windy hill near Emley, west Yorkshire. Anyway I appreciated the honesty of the surveyors, they could easily have said yes, go ahead. Apparewntly B and Q have sold loads of these windsave units and have x million in the bank from customers who are awaiting surveys. These customers will be re-imbursed if the "survey says no" In the meantime B and Q earn a healthy bit of interest. This was a major dissapointment to me however my plan is now to try to rally some support from my 20+ neighbours and attempt to get permission from a local landowner to build a larger wind turbine. Costs are a little prohibitive though. In the meantime I am waiting for a quote for a solar water heating system. Its addictive stuff this Green thinking and I fear that a number of companies realise this and are just waiting to exploit us. Rogue traders highlighted the goings on of Simplee Solar and other such rip off merchants in a programme a month or two ago.
My home made rainwater harvesting system is working a treat though, flushing all of the toilets in my 3 toileted house. Look forward to further instalments of the Ethical man report.

  • 223.
  • At 05:33 PM on 22 Dec 2006,
  • Gordon wrote:

Just about the only barely positive thing about building wind farms is that they provide plenty of temporary unsustainable jobs for a small section of any local community. I myself was once kept busy during the quiet winter months of the early 1990s carting stone to a concrete plant supplying the foundations of a wind farm above Burnley. I thought it was a pretty worthwhile job at the time but now I know the facts about wind farms I'm not so sure. With hindsight I suspect that my efforts would have been better directed as far as the environment is concerned if the stone was used for concrete in the construction of a new nuclear power station, or a fuel saving new by-pass from Colne to Skipton.

  • 224.
  • At 06:06 PM on 22 Dec 2006,
  • james wrote:

Re 219
When there are sufficient micro turbines installed to start detracting the availalble wind resource in the area, the UK will have made massive progress.

Re 220
25 to 30% on installed capacity (DNC) is good. They have to be designed to operate in high wind as well and lower wind. Anyone who has done thier research will know the typical wind distribution.

25% of 10MW installed capacity is nearly 22,000 MWH per year
2.2 million 1kW electric fires working for an hour - hardly insignificant.

Has to beat energy from a coal powerstation any day.

  • 225.
  • At 06:32 PM on 22 Dec 2006,
  • pete wrote:

post 186 quote :
and over its lifetime a wind turbine will produce over 30 times more energy than was used in its manufacture.
end quote

Disingenuous - they are of course quoting for the actual wind turbine. what has been left out ? - merely the infrastructure (tower; access roads; foundations; cost of equipment to ink to the grid) and the on going maintenance and repair costs (cost of getting to site; cost of spare components for the entire project).
And then which measure of output are they using - the real one or the quoted 100% efficient 100% working perfectly per specification ?

Do you get anything like the mpg quoted for your car ? I thought not so use the same discount to get a rough idea of the real output.

Wind farms MAY have their place - we need the real output against the real costs (in carbon or money). In the meantime STOP buying food flown in from overseas; cut out the waste (street lights as well as room lights)buy local stay local and be very very cynical about any pronouncement that is not backed by good science ! Be aware at all times that 'consultants' are PAID whether by an oil major OR a green interest group - true dis-interest is extremely rare; and normally likes to hide.

We may have to take the least damaging option - this is the REAL world - in which case nuclear is probably the only option

  • 226.
  • At 08:06 PM on 22 Dec 2006,
  • tim oakley wrote:

On your TV appearance the other night you admitted to having 12 x 50w halogen lights in your kitchen. Thats 600w! If you assume the kitchen lights are on 2000 hours a year, that is over £100 per year just lighting your kitchen. You should really be ashamed of yourself!

  • 227.
  • At 12:45 AM on 23 Dec 2006,
  • themosthandsomemanever1 wrote:

O.k. lets now see the total energy cost of building, maintaining, and SAFE disposal of ALL nuclear energy (not forgetting that firing depleted uranium from guns does not count as SAFE disposal)... And can we see the cost effectiveness of nuclear power so far?... And can we see the projected profits for the next thirty years please? anyone? The apologists for nuclear power have been anything other than clear about it.

Nuclear power is the filthiest laziest design solution and does not actually face the inevitable economic change necessary.

  • 228.
  • At 01:29 PM on 23 Dec 2006,
  • james wrote:

Re 227
And dont forget the costs of beefing up the electricity transmission & distribution system, which is assumed to be a sunk cost.
Running 400kV underground cables is 4X more expensive than overhead lines, and no one want them do they.

Replacing old nukes with new ones does not take us forward, and with exception of sizewell B they are all getting a bit long in the tooth.

If Mr Putin, or a other "gas" supplier state leader throws his toys out of pram and the west loses a large proportion of the gas supply (40% of UK power is gas based), am sure we can quickly bang up a few nukes, in time to save our economy. No way, this problem was known about years ago.

  • 229.
  • At 01:32 PM on 23 Dec 2006,
  • james wrote:

Re 227
And dont forget the costs of beefing up the electricity transmission & distribution system, which is assumed to be a sunk cost.
Running 400kV underground cables is 4X more expensive than overhead lines, and no one want them do they.

Replacing old nukes with new ones does not take us forward, and with exception of sizewell B they are all getting a bit long in the tooth.

If Mr Putin, or a other "gas" supplier state leader throws his toys out of pram and the west loses a large proportion of the gas supply (40% of UK power is gas based), am sure we can quickly bang up a few nukes, in time to save our economy. No way, this problem was known about years ago.

  • 230.
  • At 04:06 PM on 23 Dec 2006,
  • John Griffith wrote:

Regarding the debate on wind power...
It is worth looking at the experience of people who have tried it. The Hockerton Housing Project in Nottinghamshire helpfully publish data on the actual performance achieved by their two big turbines (see www.hockertonhousingproject.org.uk). Their turbines are on good clear sites and mounted on 26 metre towers. Their data for the year to Nov 2006 show that their 5 kW capacity turbine yielded an average of 410 W (about 8% of installed capacity). On a congested urban site one could expect much worse. Remember that published average wind speeds (the DTI supply these on their website for every grid square in the country) generally refer to standard measuring conditions at a height of 10 metres over clear ground. The vast majority of urban sites (and hence the vast majority of people) will not achieve the average of 4 - 5 metres per second that the tables suggest. If you plan on mounting your turbine 10 metres above your roof it would be advisable to ask your neighbours and your insurance company!!

  • 231.
  • At 06:45 PM on 23 Dec 2006,
  • james wrote:

Re 230
There are many more aspects to perfomance of wind urbines that generate variable frequency AC which is then rectified to DC and then grid connected via an inverter (like Hockerton.). If the inverter parameters are set incorrectly which unfortunately a very common occurrence with these turbines then the conversion of available energy to grid metered kWh can be massivly variant and underperforming.

Location is key but so is technical competence in commissioning the system.

It is a dangerous and misleading presumption to quote data and then criticise without knowing the technical context.

  • 232.
  • At 06:51 PM on 23 Dec 2006,
  • pete wrote:

re 227

ah yes; except that in the 50's & 60's we didn't build nukes with the idea that we would have any problems disposing them; partly as the AGR (Advanced Gas cooled Reactors) were supposed to re-use the waste from the 'standard' nukes; and just through ignorance. Most of the cost involved in dismantling old reactors is because they were designed NEVER to come apart ! SO guess what - it does indeed cost a fortune to dismantle them.

Waste disposal (since we are not allowed to have AGR's) well there is this rather cunning plan in the AEC to put the waste on the down side of subduction zones - not ideal but it lets the earth sort it out properly.

What is the real alternative - we keep getting told that there's only enough gas/petroleum to last 10/20/30 years (first mooted in the early 70's)and I presume we want to carry on blogging and not going to bed at sundown. So not having energy (electricity) is not an option; - by the way a recent UN study warned that to much demand for biomass fuel would swing agriculture away from food production.....

  • 233.
  • At 03:32 AM on 24 Dec 2006,
  • Clay wrote:

I live in the middle of canada on the prairies. We can barely justify the large wind generation windmills here in what amounts to a natural wind tunnel. The micro units which cost about half what most quotes in the uk seem to be are not financially viable.
A second thought, several years ago an island in the spain/portugal area anchored a boat and used the up and down wave action alternately pulling out and relaxing on the anchor chain to generate electricity. There was a lot of hype at the time but I haven't seen or heard anything recently. Has anyone else? I have forgotten the name of the island.

  • 234.
  • At 10:21 AM on 29 Dec 2006,
  • Gary wrote:

Many of the writers here seem to have missed the point of wind powered micro production. This is not about payback periods or efficiency statistics, it's about providing carbon nuteral electricity production. Where am I going with this? Build your own Turbine, mine produces an average 40W, it cost less than £300 pounds to build. It's not efficient, it's not pleasing to look at, but it works, and every watt produced saves me buying from coal / gas power stations. It was built from reclaimed materials so the manufacture may not have been carbon nuteral, but it has extended the useful contribution of those materials that would have otherwise been sent to the tip. So it's simple... Collect the data, visit your local tip and build your own. There are an army of people waiting to help you!

  • 235.
  • At 11:08 AM on 29 Dec 2006,
  • Paul wrote:

Bravo! At last someone on this thread who has built their own generator.
Warning - they are dangerous to set up. Just think of them as a very large circular saw! People have lost hands, arms and even their lives while setting them up.
Some excellent info on the internet on how to do it.
www.otherpower.com is an excellent starting point with sound, free information and a very useful discussion page where you can get feedback on various projects.
Many people in remote areas have successfully built small and large generators and these are proving very successful.
However, the very cheap Chinese generator used in "How to be green" is worth looking at as it comes complete with tower for a silly price.
If building your own avoid:
pulleys, chains and gears. 90 volt or more DC generators seem the easiest way to start, to give about 200 watts maximum power with four or five foot blades.
Is it true that Ethical Man is building his own generator!
That would be awesome!

  • 236.
  • At 01:36 PM on 01 Jan 2007,
  • Graham wrote:

Wind and solar power isn't new; its centuries old. Until the 1700's and the industrial revolution its all we had. Why then are some so critical of alternative energy? Because it costs money. Why do we expect energy to be cheap? Every type of energy production has it's cost, but unfortunately we have become used to not having pay that cost at the time of production or consumption. We are quite happy to pass on the cost to future generations or to to other countries in the form of permanent environmental damage. With wind and solar we pay as it is produced and consumed. This makes alternative seem more costly in the short term. In the long term alternatives are much cheaper. That is the basis of the argument that some critics of alternative energy don't seem to accept.

  • 237.
  • At 10:00 AM on 03 Jan 2007,
  • Brian Murphy wrote:

Returning to original news item. I ordered a Windsave from B/Q in November and was visited by a surveyor on 16th November who left me a copy of his report. This mentioned no problems. I applied for planning permission (cost £159.90) and rang installer yesterday for likely installation date. Phone call later in day to say my property was not suitable and should never have been approved on original survey.Something to do with random stone construction and sandstone.Now waiting for refunds!

In an attempt to start a "grass-roots" movemement for home generation of power, I have set up a web site for this:
http://beehive.thisisgrimsby.co.uk/default.asp?WCI=SiteHome&ID=14449
The aim is to distill the best information from the web about home power generation.
At the moment the emphasis is on windpower, since I find that the most interesting and challenging.
There must be a lot of scrap eguipment and materials lying about which could be ustilised with a little ingenuity to create useable power!

  • 239.
  • At 04:16 PM on 11 Jan 2007,
  • Steve Dudek wrote:

A few years ago I measured the wind speed on the top of a dwelling in Gateshead, its was located in an exposed position. I have found this data and done a rough and ready estimate of how much energy a domestic wind generator would have produced for that year if located on the roof. My calculations show 366 kWhr, say 400 kWhr. Taking the price for a kWhr of energy as 10p (makes the sums easy), the generator would have saved £40:00. So if planning permission cost £160.00, thats a four year wait to recover that cost. For these devices to be of benifit to the mass market they have to be cheap buy and installed say for £250 and have a life expectancy of 10 years

  • 240.
  • At 10:38 PM on 12 Jan 2007,
  • Jay Draiman wrote:

MANDATORY RENEWABLE ENERGY – THE ENERGY EVOLUTION –R6

In order to insure energy and economic independence as well as better economic growth without being blackmailed by foreign countries, our country, the United States of America’s Utilization of Energy sources must change.
"Energy drives our entire economy." We must protect it. "Let's face it, without energy the whole economy and economic society we have set up would come to a halt. So you want to have control over such an important resource that you need for your society and your economy." The American way of life is not negotiable.
Our continued dependence on fossil fuels could and will lead to catastrophic consequences.

The federal, state and local government should implement a mandatory renewable energy installation program for residential and commercial property on new construction and remodeling projects with the use of energy efficient material, mechanical systems, appliances, lighting, etc. The source of energy must by renewable energy such as Solar-Photovoltaic, Geothermal, Wind, Biofuels, etc. including utilizing water from lakes, rivers and oceans to circulate in cooling towers to produce air conditioning and the utilization of proper landscaping to reduce energy consumption.

The implementation of mandatory renewable energy could be done on a gradual scale over the next 10 years. At the end of the 10 year period all construction and energy use in the structures throughout the United States must be 100% powered by renewable energy.

In addition, the governments must impose laws, rules and regulations whereby the utility companies must comply with a fair “NET METERING” (the buying of excess generation from the consumer), including the promotion of research and production of “renewable energy technology” with various long term incentives and grants. The various foundations in existence should be used to contribute to this cause.

A mandatory time table should also be established for the automobile industry to gradually produce an automobile powered by renewable energy. The American automobile industry is surely capable of accomplishing this task.

This is a way to expedite our energy independence and economic growth. (This will also create a substantial amount of new jobs). It will take maximum effort and a relentless pursuit of the private, commercial and industrial government sectors commitment to renewable energy – energy generation (wind, solar, hydro, biofuels, geothermal, energy storage (fuel cells, advance batteries), energy infrastructure (management, transmission) and energy efficiency (lighting, sensors, automation, conservation) in order to achieve our energy independence.


Jay Draiman, Energy Consultant
Northridge, CA. 91325
1-12-2007

P.S. I have a very deep belief in America's capabilities. Within the next 10 years we can accomplish our energy independence, if we as a nation truly set our goals to accomplish this.
I happen to believe that we can do it. In another crisis--the one in 1942--President Franklin D. Roosevelt said this country would build 60,000 [50,000] military aircraft. By 1943, production in that program had reached 125,000 aircraft annually. They did it then. We can do it now.
The American people resilience and determination to retain the way of life is unconquerable and we as a nation will succeed in this endeavor of Energy Independence.

Solar energy is the source of all energy on the earth (excepting volcanic geothermal). Wind, wave and fossil fuels all get their energy from the sun. Fossil fuels are only a battery which will eventually run out. The sooner we can exploit all forms of Solar energy (cost effectively or not against dubiously cheap FFs) the better off we will all be. If the battery runs out first, the survivors will all be living like in the 18th century again.

Every new home built should come with a solar package. A 1.5 kW per bedroom is a good rule of thumb. The formula 1.5 X's 5 hrs per day X's 30 days will produce about 225 kWh per bedroom monthly. This peak production period will offset 17 to 24 cents per kWh with a potential of $160 per month or about $60,000 over the 30-year mortgage period for a three-bedroom home. It is economically feasible at the current energy price and the interest portion of the loan is deductible. Why not?

Title 24 has been mandated forcing developers to build energy efficient homes. Their bull-headedness put them in that position and now they see that Title 24 works with little added cost. Solar should also be mandated and if the developer designs a home that solar is impossible to do then they should pay an equivalent mitigation fee allowing others to put solar on in place of their negligence.

Installing renewable energy system on your home or business increases the value of the property and provides a marketing advantage.

  • 241.
  • At 11:49 PM on 12 Jan 2007,
  • John Wilson wrote:

Phew -not much more I can add to this
subject except my current experience.
I invested in a device to measure how much I am using and it is interesting if not depressing. I knew my bills were averaging 11,000kw/3months this averaged at some 1.2kw/hr,however, when you monitor the readings when you turn on the domestic stuff you need more than a simple wind genny to cover the load - washer 1.5kw, dryer 1.5kw, telly 200kw, computer x 2 400kw, kettle 2.4kw, iron 2.4,lights .6kw,fridge/freezer .6kw, security lights and system .15, you need the computer to project manage when to use them.

"Naturam expelles furca tamen usque recurret"
"You may drive nature out with a pitchfork but it will still return"
So much for the discussion about advances such as nuclear fusion vs. the more "natural" solar generated energy. What impresses some of us most is the almost universal lack of understanding of how much of a real substance with mass and weight simple air is and what this means when it is in motion. Hundreds of millions of tons (tonnes?) over just a patch of open farmland? Air encompassed within easy view over a pleasant landscape more than the combined weights of many of the world's largest ships afloat? When the world is ready to understand the potential, albeit elusive, that has always been there, the rest will follow with no difficulty. See www.integener.com .

  • 243.
  • At 01:44 PM on 19 Jan 2007,
  • Steve Burstow wrote:

I have been trying to buy a "Swift" wind turbine for 2 years. They were briefly on the market last year and were then withdrawn for modification. They are still not yet available again and, when they are, they will cost over £4000 installed. Eventually, when enough units are sold (they say!) the price will reduce to their target figure of £2500. You will get a 30% grant towards the installed cost, which helps. If I finally decide to buy one, I will wait till the price comes down. The problem is that their claims are certainly overstated and, so far, they have not answered my leading questions on various issues. These units are for roof fixing. Although I live on the north caost of Cornwall in sight of the sea, I suspect that the wind that reaches my turbine will be so "dirty" with eddies that it won't be much use.
In the meantime, I have both solar PV (1.6kW) and water heating and last year, I not only exported enough electricity to give me a cheque for £68 but also reduced my overall elecricity bill by over £100. The overall generation was nearly 1900 units for the year. I am sure that the payback period is very long but, by generating locally, some losses are saved and I feel that I am doing my bit and it's great to cut the grass on a sunny day and know that the power is free! The aim of the wind turbine is to provide power in the evenings when most is used.
The next project, when Peugeot (France) release there stranglehold on the batteries, I hope to get a locally available electric car which I can charge from my PV.
A thought ot finish with - why not go for small scale Combined Heat and Power plant - Microgen were going to launch there in 2005 but I haven't heard any more from them.

  • 244.
  • At 04:08 PM on 19 Jan 2007,
  • Richard wrote:

It's not about you Justin

The arguments in your program regarding the effect of various technolgies and electricity tariffs are based around your own carbon footprint as a snapshot in time - i.e the present tense.

You don't take account of the effect on market development of new technologies and services. The first people to use mobile phones in the 1980's had a much greater effect on the market than any consumer today. Similarly, if you buy into green technologies today your real carbon foot print will be reduced by much more than the simple present tense calculation because the effect you have in developing these technologies and markets will be much greater than any co2 they actually save while you use them.

If the logic you use to justify the use of green tariffs or wind turbines was used for other goods and services nothing would ever get developed. In market development terms you are an 'early adopter' and will never get as much from these technologies as future consumers will when prices come down etc, but if there are no early adopters there will be no mass market

  • 245.
  • At 03:22 PM on 22 Jan 2007,
  • gary wrote:

Among all the confusion about average windspeeds and cubes what becomes clear is that journalists who dont understand science and math would do better to refer these subjects to their more scientific colleagues. Otherwise the picture drawn can be very wrong. On many issues concerning wind power and renewable energy this seems to be a problem

  • 246.
  • At 04:21 PM on 05 Feb 2007,
  • Chris Hirst wrote:

Wind turbines of this sort have two major problems life expectancy and rotation speed. The life expectancy for this type of turbine is reported to be 3 years, from then on it becomess less and less productive. Also wind turbines require a braking system to prevent them taking off. The do not operate in high winds somewhere over 25mph and they then have to be reset once the wind speed has reduced, and where is the reset switch? 2metres above your house. The goverment should just supply every household with 5 energy saving lightbulbs!

I very much appreciate these blog posts because, between the inevitable extremes of opinion, there are some smart cookies who do seem to know what they are talking about and can share some worthwhile facts.

Hence I have revisited after quite a while, as a consequence of a BBC news report this morning, the content accuracy (or at least diligence to put PR in context) of which rang a few bells in my mind.

My main concern was that the claim was made that a new windfarm would supply half of Scotland.

I raised some doubts on my blog - http://junkk.blogspot.com/2007/02/talking-heads.html - and it seems they MAY be founded, but so far those involved in the discussion would be the first to admit we don't know.

Should anyone who does revisit these pages some answers would be appreciated.

I fear that my faith in objective reporting, even my our premier national news channel, is being seriously eroded as it becomes more and more of a PR-patsy for government and other organisations who wish to be seen to be doing 'good' in pushing their agendas.

My only concern is delivering genuine enviro-ROI from initiatives that will improve my kids' futures, and not some pol's career, activist's pension plan fund or commercial interest's lobby pot.

Or, for that matter, some unconcerned journalist/editor/producer's desire just to fill a slot under the name of 'news'.

  • 248.
  • At 03:13 AM on 24 Feb 2007,
  • michael wrote:

Hmmm… I guess you are right regarding DOMESTIC wind mills. Based on your facts, they are not helpful… So I still believe that only the professional wind farms can generate reasonable amount of power (since they can be bigger in size).

  • 249.
  • At 01:41 AM on 02 Mar 2007,
  • Mr G wrote:

Of course, it is usually more cost effective to reduce usage (e.g. by insulation) than to generate alternative sources of energy. The best way to avoid new nuclear, or a landscape blighted by wind turbines is to use significantly less energy.

The DTI has recently awarded a tender to various suppliers to stimulate the micro generation market by offering grants (£48m total) to public sector groups looking to install micro-gen. Hopefully, if this is successful it will provide a body of technical experience, and will scale up production to the point that unit costs drop. This covers various technologies including ground source heat pumps, solar PV, solar thermal, biomass and mini-wind.

  • 250.
  • At 11:20 AM on 05 Mar 2007,
  • Jon wrote:

Just for the record, yes micro wind turbines can't live up to their claims where there is no real wind, or prevailing wind. To blow them out of the water altogether, nationaly is a bit of a foolish move ("If I read it on the BBC, it must be true!"). Wind maps actually show, the west coast of England Wales, Scotland along with the South of England as good locations. Especially Scotland Have a look at their prevailing winds (and they wear kilts!). So yes, Southeast Centrics ought to look at what resources we have in abundance, can I suggest Solar? That is if you have to do anything... you can alternatively mitigate your usage and buy your power from renewable sources.

A clue to Wind Generation....

Is there a wind farm near you?

If not, it probably is not commertialy viable.. (not rocket science, just simple ecconomics).

  • 251.
  • At 01:26 PM on 05 Mar 2007,
  • Stig wrote:

Re post 173:

"The noise levels produced by these turbines haven't been considered by the manufacturers.

The B&Q turbine produces a noise level of around 55 dB(A) 5m behind the turbine."

My house (and main bedroom) is only 2 metres from my neighbour's proposed mounting point, (though it would be 3metres below also).
Typical background noise levels in suburban areas are around 35-40dB(A).

I have successfully persuaded planning to reject the turbine (it was actually part of a planning application for an extension to the house) on the basis of turbine and blade noise, esp. at night when the ambient noise levels would otherwise be very much lower than the 'average' quoted.

  • 252.
  • At 12:17 PM on 06 Mar 2007,
  • BOB UNDERWOOD wrote:

A report on wind a domestic wind turbine appeared on this web site in Oct 2005

http://news.bbc.co.uk/1/hi/magazine/4374748.stm
I am a sceptic about them. Can anybody advise me what happened to this turbine and how many kilowatt hours it actually produced in a 12 month period. There seems to be plenty of theories, but very little facts based on practical experience.
If any one know this info, please e mail me and convince me they are worthwhile.

  • 253.
  • At 02:14 PM on 08 Mar 2007,
  • CG wrote:

If you don't want to publish my post of yesterday, you could at least email me the reason. Something like the BBC is in the pockets of politicians would be probably near the mark.

  • 254.
  • At 01:13 PM on 09 Mar 2007,
  • Simon Pons wrote:

Before critising wind turbine to much we should consider how much wind is in the area we plan to put one in. Of course wind turnbines will be inaffective if there is not enough wind. It is relatively cheap to assess this with Anenometers on offer such as that offered by www.speedofthewind.com where for £70 or £5 per week you can buy or hire one that datalogs onto a PC.
Simple analysis such as this tests the viabiliy and will determine whether a wind turbine will recover a return on investment. Bear in mind that a return on investment of 20 years is the same as having your money in a high interest account in a bank therefore is a reasonable return

  • 255.
  • At 04:37 AM on 10 Mar 2007,
  • Jonathan Wangford wrote:

I have spent the last 4 1/2 years developing a micro wind turbine suitable for domestic applications. I am 3 months away from my initial product release, and hopefully about 12 months from full production.Many of the issues mentioned here have been addressed by my design, such as noise and vibration. Also I have addressed the problems of extreme wind gusts and high wind speeds,using features such as a blade pitch control constant speed unit.
However, it is impossible to beat the basic physics which dictates how much power can be produced, particularly in poor locations, so I have to agree on that point.

But I don't think that the concept can be written off so quickly. There have been many comments about the amount of energy required to make a micro wind turbine, and that many of them will never produce as much power as they needed to be made in the first place.
My argument is, if companies didn't make wind turbines (or solar water heaters/pv panels, etc) they would make something else. Or, imagine if every company made only wind turbines. Eventually the world would be full of wind turbines,which would become a dominant source of energy.
Also, the micro wind turbine of today, is probably the equivalent of the Wright Flyer. I guess that if weblogs had existed 100 years ago the Wright brothers would have earned a few skeptical comments.
In some ways the world is fortunate today that the price of oil is driving research and development into alternative, renewable energy devices. They are, in my mind, the answer to the problem. Imagine if a few large corporations decided to put as much R+D effort into renewable energy devices as they put into, say mobile phones.
I have no doubt that highly developed RE devices will be a big part of the future. I would certainly not be brave enough proclaim that the ideas are a dead end.
Meanwhile I will continue pursuing my vision. Or should I heed Justin's advice, and maybe turn my efforts towards developing the next latest, greatest Ab Machine. I mean we really need more of them!

  • 256.
  • At 06:02 PM on 13 Mar 2007,
  • andy wilson wrote:

Anyone who thinks the WindSave turbines will save money is living in Cloud Cuckoo land. Where is the data to prove this? Its easy enough to fit a meter to measure the usable yield per annum ( the surplus spilled back into the grid for free on windy nights would be ignored). In a typical urban location, with average roof top wind speeds of about 2m/s, you might get about £10-20 worth of electricity back per annum with a WindSave turbine.

Get real people, wind energy is a great technology....in the right place. These silly little turbines will take far more energy to make than could ever be recouped in the short lifetime of the product.
Funny how these products were put on the market without realistic tests being carried out by the manufacturers.
Incidentally, the average figure quoted of 3300 kWh per annum for the UK seems very low. In Ireland ( where I live) the figure is 5-6000 kWh depending on who you believe.

Other companies to be wary of:

Surface Power (describe themselves as the Ryanair of renewable energy, which speaks for itself really).
Hard to find a product worse than the WindSave turbine but Surface Power's 460w product would be a close contender.
e mail: info@sustainability.ie for more gen on Surface Power.


Navitron - their evacuated tube solar panels are among the worst of 160+ solar panels tested by Swiss research organisation spf ( see www.solarenergy.ch and check out gross efficiency figures).

This does not bode well for their wind turbines.. but maybe I'm prejudiced.

South West Wind Power ( Air 303/403/ Air X etc) The Air X was tested by independent wind expect and author Paul Gipe, and found badly wanting.
(SWWP's larger turbines may be better products, but no independent data available)

There's more but I suspect the point has been made.

  • 257.
  • At 05:06 PM on 17 Mar 2007,
  • Dennis Walton wrote:

Re: electricity consumption. There's no need to guess your consumption (#256), you can get the figures off your electricity bill. My 5-year average is 1803 kWh pa. Yep - it's low - waste not, want not! Looking at the complete picture I agree with those contributors who have stressed the need to distinguish between power sources for different purposes. Heating can be provided in various ways, but we seem to be stuck with electricity for our household gadgets. Economy requires little or no investment and the payback is immediate. But replacing appliances with 'low energy' models before the end of their useful lives doesn't look like good economics to me. (#89 and #97)

  • 258.
  • At 12:57 AM on 18 Mar 2007,
  • Neil wrote:

I hesitate to consider fitting a domestic wind turbine for one reason.
That is the noise and vibration it will cause being attached to the house wall. Will it sound and feel like a spin dryer when its blowing a hooley.
Does anyone here have any direct experience of living with a domestic wind turbine. I would be interested to hear from the converted?

  • 259.
  • At 05:05 PM on 19 Mar 2007,
  • peter wrote:

Wind powered generation needs careful planning to get any gains. Both the type of windmill and the range of windspeeds needs to be accounted for. Multi bladed turbines(5 or more blades)generate power at lower wind speeds, but quickly overrev if the speed picks up. The less blades, the higher the wind speed needed to drive it.
You should look at installing a 3Kw hydrogen fuel cell as a Combined Heat & power unit. All your green energy sources could feed it (through electrolysis of water, 97% efficient) and you get efficiencies of 80%+) and you get the electricity when you need it and store it as hydrogen on windy sunny days.

  • 260.
  • At 03:57 PM on 20 Mar 2007,
  • C Schoen wrote:

Have you any experience with

http://www.motorwavegroup.com/new/motorwindpressmaterial

the new Hong Kong based system. It promises much greater output and is very inexpensive.

Charles

  • 261.
  • At 10:25 PM on 27 Mar 2007,
  • David wrote:

Re post 251
Our neighbour has applied for planning permission to put up a B&Q turbine on the gable end of his house above a 6ft passageway between our houses. I'm glad to see that some planning departments take due consideration of the potential noise nuisance however we are also very concerned about the significant visual impact (it has to be mounted well above the ridge line) and safety implications if it were to fail - our back door opens on to our side way almost directly below the proposed installation. Does anybody know if there are planning guidlines which prevent such installations in densely populated housing areas or can offer any help/advice ASAP on these issues?
We are not against renewable energy by any means but surely there needs to be a balance between energy saving and quality of life!

  • 262.
  • At 10:11 AM on 30 Mar 2007,
  • Colin wrote:

Re post 251
David,

Your neighbour should ask B&Q: if the Windsave turbine is so good at saving money, how comes there are none on the roofs of B&Q stores? My store in Norwich would ideal, no high buildings around and I expect B&Q are drawing electricity 24 hours a day, so they will not have to give any unused electrons away to the grid. But the last time I looked there were no Windsave turbines bolted to it.

And they could also ask Windsave where there satisfied customers are; all I am seeing the the web are reports on how little electricity this turbine is generating.

Still, your neighbours will have a nice bit of "green" bling attached to their house, and for some people this is worth the £1,500 they have paid out - some it it taxpayer's money.

  • 263.
  • At 01:42 PM on 13 Apr 2007,
  • mr justin stovold wrote:

Not being fantastic at maths I cannot argue against you, but there are one of three ways round the problem {possibly}. 1, the amount of electricity you consume at night reduces so that you can store the unconsumed power for use at a later time, incorporate a solar panel into the equasion so that you are producing enough, or simply feed any surplus energy back into the main grid. This is simply my opinion.

  • 264.
  • At 09:19 PM on 13 Apr 2007,
  • Michael Allen wrote:

If you can get the turbine to go faster in a light breeze, this should make things better. One idea would be to put the turbine in a funnel. If you make wind travelling at speed X go in a funnel which reduces from end to end by 50 percent - won't the wind be moving twice as fast when it hits the blades?

If you are in any doubt of this effect stand between the Cunard and Liver buildings in Liverpool on a day with a light breeze.

My thanks to Rolls-Royce Filton for 6 marvellous months as a student in 1986!

  • 265.
  • At 09:52 AM on 14 Apr 2007,
  • CG wrote:

Yes, and when the wind reaches gale force your wonderful funnel gets blown to bits along with the turbine. There's very few new ideas in wind energy, and if you don't see your idea in use it's because it's been tried and failed.

The problem with the Windsave turbine is high wind speeds; it cuts out at 14 metres a second, no other wind turbine of its size has a cut out speed. Even the large turbines can continue generating power in wind speeds of up to 60mph before being turned out of the wind. It's in the high wind speeds where most of the energy is. It's like wait ages for the last bus and then finding it only goes to the next bus stop instead of all the way to the bus garage.

  • 266.
  • At 02:31 PM on 20 Apr 2007,
  • Ethan wrote:

I live literally on the northern coast of Scotland in an exceedingly windy location overlooking the North Atlantic. Perfect for a domestic wind turbine, there of plenty enough commercial ones here already. The problem with these products is that they are very jerry-bilt and like any commercial product, extraordinary claims are made about their capabilities which don't get lived up to, a 'one size fits all' attitude is adopted in their design, they are made to made a company rich and not to save anyone money or reduce any carbon footprints. The current flimsy windsave product would be blown to pieces here in Sutherland and most of the time would be spinning like crazy but not generating any power because of its cut-out.

If the government is serious about encouraging people to install and use these devices to enable people to reduce their carbon footprints then power generation levels need to be increased, robustness increased and profit margins capped, with grants given for more realistic design of viable and economical units. The technology behind this is frankly very old, even Thomas Edison could have designed one that worked better than current offerings, and it would have lasted a lot longer too. It's about time someone came up with a marketable product that didn't amount to being little more than a rip-off.

  • 267.
  • At 02:02 PM on 23 Apr 2007,
  • Ray Begg wrote:

I have a Wind Turbine in the midlands. In 4 months I have produced 90.7 Kwh of electricity, this seems like a bit of a result maybe not enormous but still helps.

  • 268.
  • At 02:35 PM on 24 Apr 2007,
  • CG wrote:

Rag Begg,

That's about £27 per year, if the summer is as windy as winter. So if you paid £270 for your turbine it will only take 10 years to pay it off - if nothing goes wrong with it in the meantime. What make of turbine is it, and how much did it cost?

  • 269.
  • At 10:00 AM on 11 May 2007,
  • Ravi wrote:

I am one of the few people that have actually installed small scale wind turbines. I installed about 50 Swift turbines for my previous company, all of which were recalled due to manufactoring faults.
The applications are limited but in the right circumstance - open area, as high as possible, strong walls and lots of steel work to support it they can be effective generators.
But the cost of installation and amount of energy generated would never really balance - it would never pay for itself. But saying that they look good and at the end of the day would save carbon emmissions to some degree, which is the point really.
Although I'd never buy one, Solar PV is they way forward IMO!!!

  • 270.
  • At 06:02 AM on 21 Jul 2007,
  • Mike wrote:

No, I am afraid you're right, Wind power really is best suited to commercial-size "plantations" on the North Sea coast in Friesland or Scotland, NOT in suburban Bristol (or whereever). What shocks me so much is that people seem to be under the reverse impression. National power generation _should_ include a portion of wind power, but it will probably never be the base-load generation source simply because of the wide variations of generation due to that cube-law, as you note. (I say probably because given enough generators across a wide variety of lands, and a worldwide electricity network, you COULD make it so, without doubt.) Still, it can be very useful as a supplemental alongside, preferably, hydro-electric generation (which has a rapid response time, unlike coal or nuclear). Take heart, yours was a useful experiment and its conclusions are sound for your circumstance. I just hope it does not discourage ANY action.

  • 271.
  • At 07:09 PM on 23 Jul 2007,
  • Lionel Tiger wrote:

Domestic electricity from local windfarms is a good idea. There is however an exponential connection of the power generated for a given increase in size. Therefore generating electricity using small domestic turbines is relatively small fry, despite the fact that distribution losses are lower. A much more effective way of generating your own electricity is using a new type of Combined Heat and Power gas boiler, in what is known as a micro-CHP set up. Currently in their infancy, they generate electricity as well as provide hot water in a central heating system. They work by having a gas turbine connected to an electrical generator. The turbine combusts the gas to generate heat, which is used to heat water, as a normal boiler, as well as additionally turn an alternator to provides electicity to the home. With a power rating of several kilowatts, it is possible to generate a much more significant amount of electricity from this otherwise lost source than using small wind turbines. If houses had these, and generated a lot more of their own electricity, and put to good use the heat that most coal and gas fired power stations have no use for, the large quantities of lost energy in the form of heat and steam to the atmosphere could become unnecessary.

  • 272.
  • At 09:35 PM on 23 Jul 2007,
  • Flat Roofer wrote:

Nothing in this world is as it seems. Nearly all decisions taken on our behalf for our so called benefit are false.They are political decisions,and if they happen to benefit us then that is a pure accident. Windmills for instance,of any size,-----I would say that 99% of engineers will tell you that they do not make economic or green sense.Only the flat earthers disagree. So called global warming,------Does not exist,but we are now being forced to take expensive measures(and they are many) against a non existent event--- Why won't the powers that be let us run our cars and central heating boilers on water? Do they even bother to answer the population? The answer to all our problems are known to a number of people and free,but nobody wants to know.The only answers wanted are those that make money even if they don't work.

  • 273.
  • At 02:16 PM on 31 Jul 2007,
  • Can't Wait wrote:

I live in the Western Suburbs of Melbourne, Victoria Australia in a town called Tarneit.
It get veryyyy windy from August to about March every year yet our government does not give a rebate for domestic wind power as it does for solar heating, solar power and water storage tanks.
As to the cost of each, the wind power works out the best return on investment down here.

  • 274.
  • At 09:46 AM on 10 Aug 2007,
  • CG wrote:
  • 275.
  • At 09:28 PM on 13 Aug 2007,
  • Derek Turner wrote:

The majority of posted items have noted that the variability of wind has a dramatic effect on domestic turbine output but there is always the national grid to ensure maintenance of supply and life continues unaffected. However, what happens when major wind farms experience little or no wind during, say, a high pressure zone over GB in November. How does the national grid make up the shortfall? Do we have to maintain fossil fuel or nuclear power stations on constant standby? Are wind farms also an eco-con?

  • 276.
  • At 11:30 AM on 19 Sep 2007,
  • david wrote:

turbines are sized for average power output not average wind speed.

microturbines get the disadvantage of turbulent flow in urban areas but can get the advantage of 'speed-up' as the wind flow passes over a roof. This is also called the 'hill effect'. Turbulent flow reduces energy yield by about 5-20% but speed-up will increase wind velocity and increase power output by the cube of the velocity increase. Advantage outweighs disadvantage in this instance.

windfarms dont need backup generation any more than is currently in place (spinning reserve) at current levels of wind penetration. If wind penetration were increased to nearer 20% this would be an issue.

Worrying me is a lack of verifiable case study evidence on microwind output levels. If there are a good few of these about, where is the figures from the sites? Surely something should be available? I wouldn't say that the micro turbines dont work, but I would advise buyers to wait until the technology produces the evidence required of an emerging technology.

I have an interest to declare, being involved with developing Solartwin solar water heating panels, as mentioned above.

My comment is that peak rating of any renewable energy technology, whether wind or solar or hydro, cannot be confused with an annual average rating.

There's a kind of analogy with buying a car which has a top speed of 200 mph, but your GPS calculating that you averaged 50 mph on a particular one hour journey.

Then, worse still, someone suggesting that you need to include the time it spent parked that day in the average speed calculation, which would reduce the average to about 2mph.

So what? Well, the same peak vs "average over a particular timeframe" discussion also happens with renewable enegy technology.

For example, the peak rating of a Solartwin panel is around 1600 watts. Sounds great. But that high output happens in rather exceptional conditions (when the sun is perpendicular to the panel and it is completely without cloud cover and when the average temperature of the water in the panel is the same as the air temperature outside.

The panel's average output over a year, in UK, allowing for night time being dark, non-perpendicular sun, cloud cover, higher water temperatures and so on is actually only about 115 watts. This works out at a "peak load factor" of a mere 7%. (115 divided by 1600)

If a wind turbine can offer a peak load factor of 10-30%, that is probably quite good compared to almost any solar panel, which will rarely offer over 10% as a peak load factor in UK. And that would take a very bright summer!

That being said, this solar water heating panel delivered about 1000 kilowatt hours of energy a year according to DTI tests performed on it some years ago.

I hope this contributes to the discussion and clarifies the distinction between expectation of peak output and annual expected average.

That being said, probably over 70% plus of UK homes will have a roof which is suitable for solar. The percentage of homes with good wind will be considerably lower, and the percentage with good hydro resources will be tiny.

But when they do have good wind or hydro, as with sun, there is free natural resource waiting to be harvested in a benign way.

why don't you consider our comment on this subject. Is the answer blowing in the wind or merely a fart!

It is far simpler to save energy than to generate energy..fact!

We believe on cost grounds and as a means of reducing ones so called carbon footprint... as most u.k homes have wet radiators as their main means of space heating fuel cost can be reduced by 10 - 15%,( independently tested!) for under £65.00 per average property. Easily affordable by most, easy to DIY taking 5 minutes per radiator, no holes hammers or mess.

Granted not as sexy as a gable end wind turbine but would potentially save you more money for a tiny percentage of the cost of a wind turbine .. with the added advantage that they have no potential to vibrate the gable end off your home.

No grants or development money no gravy train here sorry to say just a simple common sense first step.

If your looking for something more sexy... sorry. If you allocated around a grand for a turbine good news.. You should have around £935.00 or more left after fitting your panels enough to sponsor a team of Punkawallahs for a whole year to carbon offset your summer holiday and shopping trips around europe.

  • 279.
  • At 02:52 PM on 29 Oct 2007,
  • Georgia Valentine wrote:

Get solar panels.
Tend to work quite well once you battle the council for it.
Gas bill has halved twice in the two years its been on the roof.
In fact the sun is out now, time for a bath.

  • 280.
  • At 02:54 PM on 12 Nov 2007,
  • Bob wrote:

I have just looked at this website of windsave. It states a figure of C02 emissions which can be saved. Now I am not sure if this has been considered in the 200+ posts before but this figure is based on what?? How can a direct comparison be made. This surely depends upon the source of the original electrity and varies greatly upon if its nuclear, coal or in fact wind. In fact like mentioned before, there is a C02 defecit from the manufacture of this turbine as well as the other polutants produced while making this type of product. No doubt these are made in low cost economies, which have lower health and safety and environmental requirements than the developed world.

  • 281.
  • At 11:15 AM on 01 Jan 2008,
  • ian bland wrote:

Steel made from recycled scrap steel costs 440 KWh per ton to produce.Steel from ore costs twice this plus you have to pay energy costs to dig it out of the ground and energy costs to transport it thousands of miles. If a turbine weighs 50kg (Approx 112 pounds) One 20th of a ton, and studies in Denmark show that turbines produce 50% of max output 16% of the time, and 25% of output 75% of the time (this being with large wind farm type windmills)which are more efficient, then with a 1.5KW turbine you have a reliable output of 380watts for 18 hrs a day. enuogh to do four small bulbs But that is dependant on having back up generation for your unlucky six hours if needed.Energy output for 1 week is 7x 380= 2.65 Kw. 100 weeks use is 265 KW 200 weeks is 530 KW
400weeks is 1060 KW. So using the most efficient form of steel manufacturing there is a four year payback on energy assuming there is no need for any repairs or maintenance (parts; i.e. extra steel components) Nothing goes four years without failure if in continuous use!

This calculation stacks up if you are prepared NOT to use backup electricity for any part of the day that the wind does not produce enough for your needs. As soon as you use back up electricity then you have to factor in all the hundreds of tons of extra steel used in the manufacture of the turbine generators used to provide the back up, which actually makes it eco unfriendly putting a turbine up as you have necetated the manufacture of two structures to provide the same power.

  • 282.
  • At 01:41 PM on 03 Jan 2008,
  • Stew Green wrote:

- Wow Good good to see a discussion with people who can check facts and do maths
I'm sure you won't be allowed to work in the media

1. If you want to save CO2 go to bed now and get up when it's light, simplifying and not using energy in the first place,
2. having a kid adds 50% to your footprint this generation.

- 240 haven't included any losses to the inverter house side it's probably 40%

- 131 - good on you mate, but you'd save money if you were on the grid
a 2.5KW generator windy place 25% load factor = 0.625KW effective average output
a 40% house side loss so now =0.375KW average = 3285KWh a year
say 11p/KWh = 361 quid a year -£40 for your diesel = save £321/year
A 2.5kw turbine + generator costs about £12,000 +, Grants £2,500.
so 30 year payback

- 224 your maths is wrong 2.5MW is 2500KW i.e 2500 1KW fires
except it isn't cos you probably lose another 40% in convertion

- Cost viability - Not at any scale that's why wind is subsidised, Ah but if prices double ?
- CO2 viability - yes 278 quite possibly net emitter when you take everything into account

-I almost fell off my chair when the media talk about the London array

- Seems when it's windy they can turn down the gas generator a few miles away by annual averages of 25%
(I wonder who sells them the gas ?)
- Bottom line
a 1KW generator ends up just about powering a 150 W lightbulb which in turn gives you actually 30W of light
- People often end up using more power cos they think it's OK cos it's green. Don't look at everything with green tinted glasses or look for magic solutions, just DOWNSIZE

  • 283.
  • At 05:57 PM on 13 Jan 2008,
  • mikey dreadly wrote:

I have 6 solar panels installed on my house roof. They definately contribute between 25 and 30% of my yearly electrical consumption.
I'm now hoping to install a wind turbine to my chimney which will no doubt compliment the PV panels and bring down my electric Bill.
Electricity and gas prices are going up by 25% this year and keep rising.
I way I see it is that I chose to invest my money in something that seems worthwhile and actually is Fun!
my children learn about the weather/climate and when its sunny or windy we generate electricity that is ultimately free and will recoup the investment.
People invest £1000's in nice /flashly cars which devalue almost instantly.
If the government just gave bigger incentives into renewables,so they were easily affordable for all,as a country we could save millions for ourselves.
The German govt. give 8 times the money per kw/hr exported from domestic renewable sources.
Its not pie in the sky its fact.



You are correct in saying small roof top mounted wind turbines are no good. They are no good to the structure of the building in which they are attached and no good at producing power either!
People interested in investing money in one of these items should instead club together and buy a share in a proper wind turbine, that way they will make a REAL difference to the C02 emissions being dumped into the atmosphere each and every day.

  • 285.
  • At 10:41 AM on 15 Mar 2008,
  • CG wrote:

It's a bit bloody late to worry about whether the Windsave does any structural damage, after you have spent £1500, some of it taxpayers' money, if you got a grant, to buy the silly thing. And all to get, what I presume you mean, 50kw hours - about £5 worth of electicity.

  • 286.
  • At 09:45 AM on 17 Mar 2008,
  • CG wrote:

If this bloody blog can't go any further than 285 posts, shut the bloody thing down. My last post looks rediculous now that the BBC has wiped out the previous 285 post.

  • 287.
  • At 08:20 PM on 17 Mar 2008,
  • David Frise wrote:

Excellent debate surely two points of note;

1. The embedded carbon produced from the manufacture of your micro wind turbine or indeed your photovoltaic panel is probably never recovered.

2. Do we really believe that micro generation if sold back to the grid causes a gas turbine somewhere to slow and save energy? It actually warms the network and then has to be mechanically cooled to maintain efficiency.

  • 288.
  • At 06:41 PM on 25 Mar 2008,
  • Alan wrote:

I'm writing this well after the 'sell by date' on the original article, but have been casting an eye around on this subjest as I feel that the technology is likely to improve in efficiency as time goes by. From what I have read here and elsewhere it does seem likely that domestic turbine supplier are operating on a slightly optimistic sales pitch. That said, I must pick the original author up on his misleading line about the drop off in power with falls in wind speed. While I have no doubt that his lower figure of 120w (from a 6m/s windspeed) is true, it would be incorrect to say that 120w will only power a single, energy saving light bulb. I don't know about you, but the very cheap, energy saving bulbs I have been able to buy for years in IKEA, and now in B&Q and other outlets, run at between 8 and 11 Watts; this presumably means that 120W would run several of these at any given time. This does not seem half as bad as stated in the above article, as it would likely mean effective running of all household lightbulbs in any normal home - more appliances if the energy were storable during times of low use (such as when everyone is out at school or work during the day).

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