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Why micro wind turbines don't work

Justin Rowlatt | 16:46 UK time, Friday, 11 December 2009

burbo_getty595.jpgThe most dispiriting thing about trying to live a more environmentally friendly lifestyle is that it is all about not doing things.

We are told we have to stop flying, stop driving, stop eating meat, stop heating our houses... the list goes on and on.

So it is a nice change to be told that there is something you can do which will reduce your impact on the environment AND requires that you buy yourself a nice bit of kit to boot.

Bring on the domestic wind turbine!

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What could be more environmentally friendly than harvesting electricity from the wind and what better ethical badge of honour than a turbine spinning on my roof?

That's certainly what I thought three years ago, when my family and I were challenged by the Newsnight editor to try to make our lifestyle greener.

Unfortunately, I wasn't the only wannabe ethical man to want to reap the wind. As I began exploring the possibility of erecting a turbine on my terraced London home the Tory leader David Cameron announced his ambition to do the same.

The question was, who would get theirs up first?

Three years on and neither I nor the Tory party leader have a turbine on our roof.

turbine_afp226.jpgThe answer is very simple. In most urban locations in Britain wind turbines simply do not work.

Yes, they spin, but they do not generate significant amounts of power. Why not?

Here's the science bit... (don't worry, you will be able to follow it).

A simple equation gives the power of the wind. Power = 0.5 x collection area x the wind speed cubed.

What it tells us is that the power of a turbine is related to two factors: the size of the turbine and the strength of the wind.

Let's look at size first.

Cast your mind back to your GCSE maths (I'm old enough to have done O-levels). No doubt you dimly remember that the area of the circle is equal to the constant pi (3.14) times the radius of the circle squared.

What that means is that as you increase the length of a turbine blade, the collection area increases disproportionately.

Take the micro turbine I was planning. Its blades were 1.75m long, giving a collection area of just under 10sq m. Tiny.

california_getty226.jpgCompare that to the wind turbines I visited in Texas earlier this year. Some had turbine blades 45m long, giving a collection area of 6,358sq m. Huge.

The message is clear from the maths - small turbines have disproportionately smaller collection areas and therefore generate dramatically less power.

And what about wind speed?

The key here is that cube function on the wind speed. The power of the wind is related to the cube of the wind speed. So, at low wind speeds you get virtually nothing. When it really blows it you get a lot of power.

Here's why. Double the wind speed and you get eight times the power. Quadruple it and you get 64 times as much. Eight times the speed and we're talking more than 500 times the power.

The figures given by Windsave, the company that was going to install my wind turbine, confirmed that.

It boasted that its 1.75m turbine would generate 1kW of power at speeds of 12.5m per second.

Pretty good, but 12.5m per second is a force 6 wind, a decent breeze.

Halve the wind speed to six meters per second (a moderate breeze) and - thanks to that cube law - you now get just 120 Watts - that's two standard incandescent lightblubs (10 energy friendly compact fluorescents).

Hum, not bad.

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 4m and 5m per second. (You can find out the wind speed in your area here.)

At those speeds I'd be lucky to get 25 Watts. That is barely enough for two energy saving light bulbs. Nowhere near enough to live up to the company's promise of reducing my electricity bills by "up to 30% a year".

The message is clear. In most UK locations micro wind turbines will never generate significant amounts of electricity.

It makes a nonsense of the claim made by the Energy Saving Trust, when I was planning my turbine, that domestic wind turbines could supply 4% of all the UK's electricity needs and cut carbon dioxide emissions by 6%.

It also suggests the government should think again about offering a generous feed-in tariff for power generated from micro wind turbines.

And, if any more proof of my point was needed, in September this year Windsave went bust.

Of course, not all wind energy is a dead end. What our calculations tell us is that power increases dramatically as you increase the size of the turbine and the wind speed. So, a 10m turbine in a 10 knot breeze generates 100,000 times the power of a 1m turbine in a 1 knot breeze.

Indeed, if Camden, my local council, gave me planning permission for one of those Texan whoppers it would generate significant power - something like 200kW - even at 4m per second.

But even these impressive figures can't disguise the inconvenient truth about wind power: except in storm conditions it is - compared to fossil fuels - a very dilute energy source.

norfolk_afp226.jpgProfessor David MacKay, the new chief scientist at the Department for Energy and Climate Change, has done the maths on this. Instead of kW, he calculates power in kWh, and he estimates that if we put wind turbines across the windiest 10% of the country, we would generate only 20 kWh per day per person in Britain.

According to MacKay, it takes 40 kWh to drive the average car 50km.

Add in offshore turbines covering a third of the available shallow water locations (44,000 turbines) and installing deep water turbines in a 9km-wide strip all round the entire British coast and you get an additional 48kWh day per person.

That's a lot of power, but even on quite conservative estimates the average UK resident uses 125 kWh day.

It leads to a dispiriting conclusion. Wind is, at best, only a very partial solution to the problem of how to generate low-carbon energy.


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  • Comment number 1.

    Wind turbines don't produce much energy for you but for people like me living in a relatively windy area they are good.

    Unfortunately the up-front cost is prohibitive.

    The way to get these things much cheaper is simply amend building regs - each new abode must have a solar panel or wind turbine.

  • Comment number 2.

    The hold that coal and oil have on governments do not allow for proper technologies to be developed. Oil providers are trying to reduce Western demand so they have more to sell to China without a large increase in costs which of course would make alternative viable. This is why you are told on every passing day that you are the problem. You need to change your lifestyle so oil companies will be able to protect their interest. Now be a good citizens and do your part to protect big oil. Hydrogen is the best of what is available but hydrogen is a direct competitor to oil and coal and the lobbyist and their political handmaidens are not going to promote that. Governments are simply owned by banks and big business and should not be seen as facilitators of change. They support the status quo and the status quo is represented by those funding their re-election. It is about money not the environment....politics, not ethics or responsible decision making. Prostitution is practiced most openly in Nevada and Washington D. C., London, Tokyo and Beijing.

  • Comment number 3.

    You forgot to mention that those big wind turbines are also erratic, so you need a big back-up source of power to manage the lows. Since it is hard to just flick a switch on a generator so you have to have hem running at some level anyway, you end up with a lot less than a one for one substitution. Also you have build and pay for the back-up source so the all-in cost of wind is even higher.

    As for the environment, wind turbines kill an appalling number of birds, especially those ones we get emotional about like eagles, hawks et al. And then you have the spoiling of the view (that sounds rather quaint, but isn't the whole point to protect the environment including the view?).

    So all in all, pretty poor alternative. What no one seems to want to accept is that we had better get a lot more serious about improving nuclear energy, because long term that is the alternative both environmentally and economically.

  • Comment number 4.

    There is nothing environmentally friendly about nuclear power. It is completely dependent on the mining of uranium, the enrichment of that uranium, the disposal of toxic waste, and the risk of more Chernobyls or 3Mile Islands. Aside from involving the earth's most toxic naturally occurring element, all those activities are carbon intensive as well.

    (Mercury is only the second most toxic element, but spilling some on a stove element has lead to instant death and the evacuation of an apartment block)

    Anyway, we may need improved super-capacitors (aren't those being worked on?), in large arrays, to store windy-day wind energy for not so windy days, and sunny-day solar energy for not so sunny days.

    We will also need to learn to use less. Traveling by bicycle instead of car (and electric rail when needed), should help a lot. If only they would build enough electric rail service, to ban private-motor vehicles, then everyone would feel safe on the roads.

  • Comment number 5.

    Headline: Why micro wind turbines don't work (with relative directions of vanes on weather cock and turbine in telling complement)

    Text: In most urban locations in Britain wind turbines simply do not work

    And folk wonder why the public are cranking eyebrows. There is what we know, there is what we don't, and there is what we are told. Seldom is this done without a narrative being enhanced or an event being interpreted.

    Which becomes pertinent, and key, when it comes to what we are told*, especially about vast amounts of money to be dedicated to 'solving' things, which seem a bit shy on detail as to what, specifically, and how measured to assess enviROI, etc. Numbers do matter, even as science gets settled (if often in creative ways), and passed on by those we pay, and trust to be our guides.

    It makes a nonsense of the claim made by the Energy Saving Trust,

    But I am glad I persevered, as there was much to ponder of value, and I appreciated the maths lesson. Makes me wonder why such calculations are often beyond those who claim (all dutifully passed on by those copy-typing press releases as 'reporting') that 'such and such 'could' power 1/2 of 'so and so' for 'free' (exc: construction, operation, maintenance, repair and disposal).

    And there is also the power of editorial, often, possibly, via omission:

    3. At 9:01pm on 11 Dec 2009, simon noble wrote:
    You forgot to mention that those big wind turbines are also erratic, so you need a big back-up source of power to manage the lows.

    One just has to hope that, when given the massive importance of the basic intent to reduce GHGs, and the vast monies involved in securing that laudable aim, those with the power to take and dispense the funds in securing this, plus those tasked to hold them to account, know what the heck they are doing.

    And are guided by honest, unselfish influences and not the lures of personal advancement, ratings, career influence, lobby-influence, bonuses, targets and box ticks.

    *Clarified, often, only after the the hyperlink and/or in the small print.

  • Comment number 6.

    We 'did' windmills a few centuries ago. As soon as something better came along we moved on.

    Windmills appeal to politicians for several reasons.

    1) They are very visible - like a row of big adverts saying "we are doing nice things".

    2) They avoid any difficult choices about nuclear. They are a displacement activity at best.

  • Comment number 7.

    Being green is fabulous. You do nothing yourself and wait for the government or your neighbors to do the hard stuff. Like inventing super-capacitors or cycling more or composting...

    You also get to fly to conferences about banning flying. And drive to anti-car demos.

  • Comment number 8.

    Hi all,
    I really don't agree with this point of view .
    first of all we should all reduce our consumption by insulating our houses and by using the right vehicle for the right purpose
    most of us in the uk, in france and else where are living in non insulated houses loosing 90% of the energy used for heating , most of us are using our 100 KW cars just to go our 1 km away for shopping etc etc etc etc .
    When I see all those mothers of one driving their only child at school using the expensive 4X4 cars their poor husband had to pay it drives me crazy ....
    all of this can definitely change, insulating houses and using small electric cars or electric scooters for the low range daily trips .
    I am personally commuting on a 100 km basis using an electric scooter consuming not more then 3 kw, and insulating my house made it possible to cut by 5 my heating wood consumption .
    after having reduced our energy consumption all the electric micro generation personal systems will be useful (solar panels, wind turbines etc) , and all the alternative source of power will play a significant role in our lives or our children .
    it is a really war we will have to declare to the climate change causes.
    times for skepticism is over, now it is time for change, we will not be able to keep the same life standards, the 125kw daily figure will have to be cut by 4 before attempting to switch to any alternative source of power .
    are we gonna be able to live on a 30 km daily figure ? think of what was the 1950 uk citizen daily energy consumption ? much lower I thing , and now with 30 kw/day/person using low consumption houses, vehicle, computers etc we would be able to live decently .
    only my two cents

    sorry for my terrible English

    jean michel


  • Comment number 9.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • Comment number 10.

    The blog mentions David MacKay, what it doesn't say is that everyone interested in this sort of thing should read David MacKay's free book! It explains loads of bunk about windfarms, coal, nuclear etc. and does it in a balanced, informative, insightful way. Go to, you won't be sorry.

  • Comment number 11.

    You gave this equation:
    Power = 0.5 x collection area x the wind speed cubed
    What units? Power in horsepower or kW? Area in sq. ft or sq. metres? Wind speed in metres/sec or mph? One can't assume, except in a scientific paper, that SI units are intended.

  • Comment number 12.

    sounds like you're using the wrong average ... you need a cube root of the average cubed speed. a 10 knot wind half the time makes 4 times the power of a 5 knot wind, even though the average is the same.

    Also, those large turbines with disproportionate effect present a disproportionate difficulty, so I suspect that there are viable home solutions, possibly spread cheaply over a wider area and possibly involving the roof surface aerodynamically

  • Comment number 13.

    Well done for going against the dogma.

    I've been saying this - and taking flack - for years.

  • Comment number 14.

    EVERYBODY knows wind power is only part of the solution. Just as nuclear could be, coal could be, oil, gas, yak dung... they are all only part of the solution as at present we have diversified electicity production. I considered the concept of a wind turbine on a terrace roof in London over twenty five years ago. Engineering knowledge was suffient at that time to dismiss it. However contemplate a communal wind turbine on your block or your street that is a little more possible with community action.

    Best wishes

  • Comment number 15.

    Micro wind turbines work, but they are just part of the mix of renewables. Wind turbines are only expected to produce 30% of their theoretical maximum power, so lets forget the stupid complaint that they only work a third of the time.

    The other complaint is that they are intermittent electricity producers.
    Energy storage at present is poor ie such as many large storage batteries. However if utilities have legally to accept surplus home generated electricity and pay fair prices, then electricity can be purchased back from the grid when needed.

    Another turbine source of renewable electricity which is reliable is seabed TIDAL GENERATORS. These produce electricity twice a day for a total of 12 to 16 hours depending on the high tide times. These tide times are known years in advance so the electricity output is known. By having SEABED TIDAL GENERATORS at selected undersea sites around the British Isles the variability of high tide times is even out. The excess-to-demand electricity, produced overnight, could be used to recharge electric cars and buses, solving another CO2 global warming problem. Every renewable generating source, matters to the health of this planet.

  • Comment number 16.

    Where does wind energy come from? What makes the wind move in the first place? It's the sun!! Sun heats the ground up in different places more than others. Air warms up next to the hot ground - air rises - air moves in to replace rising air - Wind starts to blow.
    Wind is a secondary factor of the energy we receive from the sun. So why not go straight to the source!! Why go for the secondary effect.
    I heard an article the other day that said from Conscerntrated Solar Power CSP - it is possbile to produce 100% of our energy needs based on a population of 10Billion - by having CSP in 10% of the worlds deserts. Let's start building these collectors using the last of the Cheap Fossil Fuel energy we have. Build them to last. Problem solved.

  • Comment number 17.

    Your maths are good, but I doubt one reference. If each person used 125kWh/day, then a family of four would use 500 kWh/day. At an average cost of 15p per kWh, that would be £7.50 a day on the electricity bill, or £675 a quarter. I have not seen a utility bill that high and I am not particularly careful with my carbon footprint. I don't know anyone who pays that much, even friends who run small businesses. A recent episode of Bang Goes the Theory demonstrated quite convincingly that a family of four uses about 19 kWh/day assuming they use as much power at night as they do during the day

    There is a benefit to micro power units that is often missed.

    Two out of every three watts generated by a power station are lost in transmission. Transmission loss is caused by the resistance in power lines which causes voltage drops which cause loss of power. If you raise the voltage input on the receiving end of a power line, you reduce the voltage drop and the power loss. I'm not saying your micro turbine would be more effective than a special battery, but it would introduce an energy savings that you have not accounted for. Larger turbines are often used to boost power along the grid in the US; generating savings that are greater than their power output. I'm sure the same is done here.

  • Comment number 18.

    Your comments on urban wind generation are fair and helpful but you let the article down by saying that wind isn't the only answer.

    Of course it isn't, just like any other energy source or conservation technology. There are good reasons for believing that wind can supply around 30% of electricity or around 15% of total energy usage in around 10 years time.

    it's not THE answer, but it's a pretty sizeable contribution.

  • Comment number 19.

    It has been said that there is not one environmental problem that cannot be eased by a reduction in human population. This is certainly one of those problems. As well as the Earth, the UK is populated well beyond its self-sustaining capacity for both energy consumption and food.

  • Comment number 20.

    Number 3 hits the nail on the head.

    Besides, the best way to drive down energy consumption in this Country is to drive down house prices - house prices will fall sharply over the next few years anyway, but a land-value tax (to replace income tax) would prevent them rising again (as well as insuring that investment is channeled towards productive areas of the economy rather than house price speculation).

    The number of unnecessary journeys has spiralled out of control over the last decade as a direct result of the housing bubble, whereby people (almost overwhelmingly the young as a result of the baby-boomer land grab) are forced to live further away from their place of work to find somewhere affordable to live. I'm one of them and there are millions of others. Rail passenger numbers have increased by 70% from the mid-nineties - I don't know the figures for road transport, but it's probably around the same. The population certainly didn't rise by the same amount in the same period - the reason for the rise is the enforced commuting caused by the housing bubble. Not only is it bad for the environment, but bad for the UK's productivity and health. A large part of the answer is to change our warped economic model.

  • Comment number 21.

    Whilst I found this an interesting article I would have been much more impressed had the reporter continued to install the turbine, even after the news of low average wind. That way they would have had actual production data rather than the results of calculations based on estimated wind speed and equations that some on here don't believe are accurate. In fact I think that this could be a great thesis idea for someone at university.

  • Comment number 22.

    Following the comment on what we know and what we are told...
    One reason behind this (and much other) misinformation is the use of the term "up to". For example, "will generate UP TO xkW", or "can save UP TO x%", or "is the equivalent of UP TO x nuclear power stations" etc etc.

    This is the same kind of marketing abuse that can allow a face cream to claim that it will "eliminate UP TO 80% of age wrinkles" or our broadband internet supplier to claim "UP TO 20Mb of bandwidth".

    The problem with the term "up to" is that it includes any figure you like from zero upwards!

    Clearly the domestic-turbine supplier Windsave discovered this when reality caused them to go bust despite their appetising marketing promise of "up to 30% savings".

    I'd like to see all these "statistics" re-evaluated and replaced in terms of "at least...". i.e. "will contribute AT LEAST x%, or xkW", etc etc. Then we might get some real clarity on the situation.

  • Comment number 23.

    This article has restored my confidence in wind!

    It talks about 68 kWh of wind available per person from the 10% windiest land 1/3 of shallow water locations plus a 9km (5.5 mile) wide strip in deep water around the coast. But we can have much bigger wind parks than that in the North Sea, etc out to sea!

    It says 125 kWh of energy is needed per person per day, but that is all energy including transport and heating. We can be getting our heating from heat pumps and rooftop solar water heating (both of which MacKay also advocates) using much less electrical energy to power them than the heat delivered.

    Really the problem with wind turbines is the time and money needed to procure and erect them all, with a lot more raw material than was needed for our part in WWII. That's why we need to develop several other sources at the same time.

    PS. The last 2 links in Rowlatt's article are to pages of MacKay's book.

  • Comment number 24.

    As a consulting engineer involved in the specification of renewable energy technologies (RETs) for buildings almost every day, it's good to see the truth about urban micro-wind stated clearly - that it is largely nothing but greenwash, which in my book actually makes it dangerous. Because the idea of 'green' and 'sustainable' represents a huge market opportunity, the market is becoming flooded with products that are actually neither. This can be because they are inherently useless or perhaps they have some use but may be misapplied - which is the case for urban turbines. The market cares nothing for the ramifications of climate change and we need to be aware of its darker side, which acts to prevent progress in reducing atmospheric CO2 levels. I am therefore pleased to see that you are bringing the facts associated with micro-wind to public attention; let's hope people in urban areas don't install them but focus on more useful RETs, like solar thermal hot water generation for example. Please keep up the good work!

    One slight correction needs to be made to your piece. In describing what Prof.McKay has done, you have confused measures of power and energy. A kiloWatt is a unit of power, whereas a kiloWatt-hour is a unit of energy. The two are very different and are not interchangeable as suggested.

  • Comment number 25.

    Why does wave power always get ignored? Wind comes and goes, but every day we get waves, or even better, tides. The power available is massive but relatively little work is being done to develop the technology.

    I know - why not use some of the nuclear budget on wave technology?

  • Comment number 26.

    Come on Justin. Rather than just taking David MacKay's word for things, let's have a bit more thought!

    The 132kWh figure includes all the energy we waste in cooling towers at power stations. Energy demand in the UK last year was about 98kWh per person per day [DUKES]. We could get that energy from wind installed in two-thirds of shallow British waters (below 50m depth). Not that we would do it that way, but it does show that we've got more than enough wind to meet all our energy needs. That offshore wind is in addition to onshore wind (20kWh), wave power (10-25kWh), tidal barrage (2kWh), solar-thermal (5kWh), geothermal (1kWh), photovoltaics (2kWh), as yet uncertain quantities from tidal stream (3-15kWh), salinity gradients (unmeasured as yet), hydro, and a potential 50kWh in efficiency savings. [RES].

    As for that "only" 20kWh per person per day for onshore wind: do bear in mind that our current electricity demand is about 17-18kWh [DUKES], so onshore wind could provide more electricity in a year than we use.

    As for a car using 40kWh to drive 50km, well, a wind turbine produces electricity, and a car uses petrol, so that's no use at all. 40kWh is about three times what we current use for cars and taxis. So Professor MacKay has used a number that would mean the trebling of the amount of traffic on the roads! Can you imagine? It would be as busy as rush hour all day long, every single day of the year. Maybe he was in Los Angeles when he picked those numbers.

    An electric car is much more energy-efficient than a petrol car, and uses about 10kWh to drive 50km [WTGHDTA]. But across the entire population, the average distance driven is just 18km per person per day [TSGB], so average energy consumption for cars, if they were all electrified, would be just 3-4kWh per person per day, assuming the same amount of distance travelled as now.

    Yes, there are some people who want to talk Britain down, and try to make believe that we just can't cut it, and that we'll always be dependent on importing one fuel or another. They're wrong.

    And now that we can put wind turbines in water deeper than 50m (HyWind), then Britain could produce more power from offshore wind, than the Middle East does from oil [2TW]!

    Britain is the Saudi of renewables.

    [DUKES] Digest of UK Energy Statistics 2009
    [TSGB] Transport Statistics for Great Britain 2009
    [WTGHDTA] "Why Top Gear Haven't Done Their Arithmetic" by George Wallis, [Unsuitable/Broken URL removed by Moderator]

  • Comment number 27.

    See what the government has been covering up about wind turbine noise at

    Ethics here?

  • Comment number 28.

    No 17 is the first comment that mentions the horrific power losses during distribution. What this tells us is that we need far more localised power generation. This also means that large wind farms are not especially beneficial.

    Having said that the Norwegian island Utsera has cut iteslef off from the national grid. Their wind turbine produces more power than they need most of the time. They balance their power needs with hydrogen. A 20 foot shipping container is large enough for the kit needed to use excess energy to produce hydrogen which is then used to generate electricity when they have no wind. They then sell excess hydrogen on the mainland.

    Hydrogen produced is the only way a hydrogen powered vehicle can claim to be green. The vast majority of green powered vehicles are anything but green - they are merely displacement polluters - using polluting energy inefficiently to create an alternative to town centre pollution.

    Small scale hydro power is one of the best ways forward - every weir on a river is there simply to dissipate energy that could be converted to power.

    Having said all that the 17th comment also highlights one of the biggest problems. He obviously believes that it is only the power consumed at home that causes global warming. To state his energy usage ignoring his polluting transport needs shows a complete lack of awareness.

    I have read that upto half our energy usage is for heating. Any good production engineer tackles the issues that give the greatest gains first. Nuclear power will never be clean, economic or safe. What we need is to go down and use the free energy that is down their. Community based geothermal projects would answer many problems without pollution and far less capital cost than any nuclear plant.

    The biggest problem we face with any localised power generation / harvesting is that this is the hardest form for big business to dominate and so the lowest of their priorities.

  • Comment number 29.

    What i with the BBC at the moment. A string of unbalance, ill informed, half backed articles about renewable energy and alternative energy technology. Perfect examples of how a little knowledge can be a dangerous thing. Especially when combined with lazy journalism and a national platform.

    I am no great fan of micro-wind primarily because the key to wind power is understanding the wind profile of the location and very few people will know this for their own roof.

    Having said that, let me challenge you on some of the "facts" in your piece. ou seem to have fallen into the same "average wind speed" trap which I'm sure you have before. As an earlier poster pointed out there is a big difference between a constant 5m/s and 0 half the time and 10m/s half the time. Roughly 4 time difference in fact.

    You say "10% of the country, we would generate only 20 kWh per day per person in Britain". ONLY 20kWh per day per person! That's 438 TWh per year, well in excess of the total UK electricity consumption. And massively greater then the current UK target of 30% of electricity generated from all renewable by 2020.

    You compare this with an estimate of the amount of energy required to drive 50km. Talk about comparing apples with oranges. This figure is clearly based of the energy used in a conventional car powered by petrol or diesel. How is this relevant to electricity production? The reason it takes 45KWh of energy to move an Internal Combustion Engine vehicle 50km is because they are horribly inefficient (25% efficient if you are lucky). A modern electrically driven vehicle (Mitsubishi i-miev or the Nissan Leaf) will do the same with about 5kWh.

    I could go on, but suspect you won't let the facts get in the way of a snappy piece of "journalism" next time so I won't bother.

  • Comment number 30.

    I suppose the Power = 0.5 x collection area x the wind speed cubed equasion is the reason why we don't put micro wind turbines on the lamp posts in the middle of highways.

    It always seemed an elegant solution. Cars generate the wind and as high ways are already ugly anyway nobody will care the wind turbines make them even uglier.

  • Comment number 31.

    #17 Michael Wesselman - the figures of 132kWh/p/d includes all the energy used for transport, as well as industry, offices, power station cooling towers, everything: it's the country's entire energy consumption averaged across the population. So, yes, only a fraction of it appears on your utility bills.

    #24 Keith Calder - yes, kWh is indeed a unit of energy. When discussing the available resources, and total demand, David MacKay (and Justin and I) use kWh as shorthand to refer to kilowatt-hours per person per day, which is a unit of power per person (and assumes a population of 60m). Sorry for any confusion about that.

    If you want to convert to a more familiar unit of power, kWh/d x 2.5 = GW. So 1kWh/p/d = 2.5GW. And 98kWh per person per day is equivalent to 245GW - that's Britain's average power demand (there's about 34kWh wasted at point of generation, mostly power station cooling towers; hence the difference between 132kWh/d energy consumption and 98kWh/d energy demand).

  • Comment number 32.

    Surely, global warming is the answer to the energy crisis - insulated homes or not we burn fuel when its colder outside. If the mean difference is two degrees less on avarage than in the past we will burn considerably less fuel of all kinds to stay warm.

    Rising sea levels and greater rainfall should improve the prospects for hydro electric generation including tidal and wave power.

    The higher levels of carbon dioxide in the air promote more luxurious plant growth and should reduce the need for fertiliser.
    We really ought to take advantage of global warming and use the changes to our advantage rather than throw our hands up in horror at the thought of it.

  • Comment number 33.

    sometimes you have to think small wind is sometmes not there Whats wrong with lots of small hydro plants Here in Edinburgh we have a river that at onetime suported 75 mills lots of the weirs are stll there SO HOW MUCH BASE LOAD POWER IS THAT and how many more rivers run through our citys POWER MADE WHERE YOU WANT IT

    But its not big and polititans like BIG

  • Comment number 34.

    It's worth expanding a little on Cotswold Ramblers point about electric vehicles. Although they doubtless reduce the amount of air pollution directly affecting towns and cities, unless they are re-charged from renewable sources they are the worst form of CO2-emitting vehicle on the road! Take a look at the carbon conversion factors for a range of fuels (2008 net calorific values, courtesy of DEFRA). The values vary a bit from year to year but this gives the general picture...

    - Natural gas = 0.206 kgCO2/kWh
    - LPG = 0.225 kgCO2/kWh
    - Petrol = 0.252 kgCO2/kWh
    - Diesel = 0.263 kgCO2/kWh
    - Grid electricity = 0.537 kgCO2/kWh (rolling average)

    Using electric cars charged off grid electricity means that in terms of CO2 emissions they are more than twice as harmful as cars running on petrol. So much for the green electric car revolution!

    Of course, if the government manages to produce 30% of electricity from renewables by 2020 - it's declared target in the "Low Carbon Transition Plan", electric cars will start becoming a bit more attractive. But unless they re-charge from renewables they will always be worse than virtually any other fuel source.

  • Comment number 35.

    @ Michael Wesselman, the 125kWh per day figure relates not just to the electricity that you use directly, but also indirect use, such as transport. It's a slightly exagerrated statistic because if you had a wind turbine or other renewable energy technology, you wouldn't need to produce the energy that for example your commuter train uses in the morning.

    Also I wouldn't recommend using the Wind Speed Database to work out how high the wind speed is likely to be in your area, as Justin suggested. This data is averaged over a 1km squared area, and turbulent effects such as trees and buildings can produce wide variations within that area. It would be better to obtain an anemometer in order to find out the specific capabilities of your site.

  • Comment number 36.

    so the only model you have in your head is domestic or expensive offshore?

    in germany a feed in tariff generates more power than the whole of uk nuclear?

    how is it done?

    by using factory roof space, industrial estates etc so councils can generate power for the community and income for themselves.

    the power of the community is greater than the individual.

    apparently some seem to think the uk people should not even have the option [where it works] to put energy back into the system? is that a 'if i can't have it no one can' spite attitude?

    in the atomised existence most people live these days since the enclosures of common land the idea of community might seem space age.

    the only people opposing a feed in tariff are hmg [gordon has blocked every bill] and the international power companies who have no wish to lose the easy billions of cash they get through the monopoly of the one way grid.

    if you want to see how it works why did you based it on your failures and not look at models of microgeneration where it does work [ie outside the uk?]

  • Comment number 37.

    #17, #28, transmission losses are nowhere near what you claim. For electricity, there's about 2% lost in transmission, and about 5% lost in distribution. ("losses" in table 5.1 of DUKES 2009)

    #29 - spot on

  • Comment number 38.

    #34 - you're forgetting that electric engines are about 4 times as energy-efficient as internal combustion engines. So if electricity has twice the emissions per kWh, it has half the emissions per km driven - so electric vehicles are much better, already. And, as we're committed to decarbonising the grid over the next 20 years (see the 1st report of the Committee on Climate Change for details), then electric vehicles will get cleaner and cleaner.

  • Comment number 39.

    I'm not sure that wind turbines are quite the solution to climate change that people think. Correct me if I'm wrong but isn't the energy gained from a turbine taken from the wind? Of course, one turbine will make little practical difference - but a million turbines - perhaps many millions around the world? Won't these alter the characteristics of the wind, rainfall patterns, etc?

    Won't that in turn have its effect on the ecology? Has it been included in the equations?

    Mind, if these turbines can be pointed toward the East with winds coming from Siberia, I'd be perfectly happy to have them peter out before they reach the UK.

  • Comment number 40.

  • Comment number 41.

    Thanks to the 'BBC Ethical Man'. It gave me very important information.

    Note to the facts mentioned in this article:
    The fact that presently wind-energy would not equalize an average Britain's person energy-consumption, even if 10% of Britain's-area was covered with conventional wind-turbines, is a quite patchy argument for following reasons;
    * Britain's population needs to be managed (&, if necessary, reduced) to a sustainable level [what a sustainable level will be, will depend on the average energy- & resource-consumption per British citizen].
    * The average energy-consumption per Brit.-citizen can be reduced drastically without reducing living-standards (by cutting out wastage)
    * It is quite common knowledge that wind-power is & will be one part of a sustainable/renewable energy-mix {i.e. Wave-/tide-power; Solar-energy; Bio-gas-power (i.e. Methane-gas from farm-animals, garbage-sites & similar].

    General conclusion: Britain needs to change its economy towards a "SURPLUS-economy" in every sense of the word (the above mentioned issues are just a few measures to stabilise British living-standards & make average British-living-standards sustainably (future-proof) syncrhonically.
    If you like to write to me about the above issues: [Personal details removed by Moderator]Thanks - Frank.

  • Comment number 42.

    Any chance of a similar analysis on Solar Panels? There's a lot of people around saying these are a Good Thing too.

    I do note with interest when i make a train journey that Network Rail seem to be installing small scale wind turbines and solar panels to power signalling switch boxes; as these are tiny windmills this suggests either NR have been well conned or they are perhaps justifiable?


  • Comment number 43.

    And you wonder why wind turbine manufacturers go out of business? With comments like yours - no wonder!
    Obstructions cause turbulent wind which reduces the efficiency of wind turbines.
    A wind turbine will not perform well on the roof of your house because of the turbulence caused by your house and the obstructions around you!
    Micro, small and large wind turbines do work - providing they are installed in a good windy site with no or few obstructions.
    If you have an open windy area with no obstacles then a wind turbine is for you - just don't stick it on your house!

  • Comment number 44.

    A very disappointing blog.

    How is 48kwH out of 125kWh "very partial" ? It's a high proportion, much higher than the 10 to 15kWh we'll get out of the most ambitious current nuclear plans.

    To quote from David Mackay's book without referring to his overall conclusions (that we need a broad mix of cleverly put together energy systems, and there is no cheap option), is poor reporting.

    And to put so much effort into investigating the micro wind turbine option in Camden is against the most basic, widely available advice on renewable energy. Being wilfully contrary in order to generate more words for an article is also not impressive journalism.

    Worst of all, the UK Energy Research Centre, an obvious port of call for any journalist truly trying to get some facts, can provide information on backup costs for wind power. With up to 20% of electricity provided by wind, roughly as current government plans and more than nuclear can provide now or under current plans, the extra cost of backup and grid services is equivalent to the value of 5% of the wind energy produced. Beyond that the cost goes up rapidly. The conclusion is obvious: the government should implement its current wind plan as fast as possible then stop. Why are the BBC unable to present this information to the public ?

    Why not just invest in someone else's windfarm, located in a windy spot, if you want to have your share of the grid's energy provided by wind. Good energy, Triodos Bank and a range of community energy schemes offer ample opportunity to be effectively green. At the moment this blog seems to simply record a willful effort to be ineffective, and some insufficiently researched journalism.

  • Comment number 45.

    I tend to agree that wind energy is blown beyond the reasonable. I have made a study of renewable energies for use where I live. Here, wind speeds are generally much lower than in the UK. Some years ago, I wrote an essay on wind generation based on large turbines, with graphic illustrations on their weaknesses. For those interested, it may be found at:

    No mention has been made in Justin's essay about one of the major disadvantages of the micro-power turbines: these are often solidly fixed to the walls of houses or, heaven forbid, chimneys. When the wind does blow, according to a friend who was conned into fitting one, the whole house is filled with a very low-frequency rumbling as the whole wall to which it is attached becomes a diaphragm. Of course, putting it on a mast in the garden (if you have one) may avoid the problem, if no guy wires are attached to the house.

    As others have said, wind and solar may be useful complementary RESs, provided you have full scale backup available. Large scale hydro can generate 24/7 and has the advantage of being easily regulated to match supply with demand but has hosts of other disadvantages. The only other major 24/7 energy source is Waste-to-Energy and can supply about 9% of a country's electricity demand and also distant heating. The UK produces less electricity by this means than a number of countries with only one-tenth of the population. Why?

  • Comment number 46.

    I am not a scientist but I am a concered individual. I don't think anyone is pretending that wind power is the answer to all our energy woes. But the thing about renewables is that different ones can be utilised in the areas most suited to them. I live in one the windiest parts of the country and therefore one of the windiest places in Europe and if we could afford it, we'd get a turbine like a shot. However I wouldn't be so silly as to depend on it ALL the time. Solar power in the Middle East (ha! like the oil companies would go fot that), Africa and Australia could transform their energy needs. Hydro electric in mountainous places, wave hubs in places with big's so simple. Obviously the investment would be enormous, we can but dream...

  • Comment number 47.

    In reply to Tsuji-giri's comment (No 42), the Network Rail signalling and communications cabinets he sees draw very little power and are in locations remote from mains power supplies. The cabling and other costs of connecting these cabinets to mains supplies are much higher than the cost of solar+wind+battery systems, and the mains supplies are in practice less reliable in this type of application. Network Rail are saving on capital cost first, and greening their power supply (slightly) as a side benefit.

    Some local and highway authorities are adopting the same type of system too. A parking ticket meter or bus shelter with solar panels and a battery for backup os a lot cheaper to digging up the road to lay a new cable, and is probably more reliable. So when Jeremy Clarkson tells you on Top Gear that solar powered road signs and lighting are daft, remember that he's a professional clown, not a professional engineer.

  • Comment number 48.

    Why can't these small wind generators be used to trickle-charge heavy duty batteries, as they do on boats, for example? Are they not ideally suited for powering domestic low-voltage LED lighting? We need to move as quickly as we can to adopt LED lighting as we did in moving from incandescent to CFL lamps. A high power LED lamp typically runs at 3.3 watts. There isn't any economy of scale in the production of domestic LED lights (or even LED street lamps). If things can move on the need for extra generating capacity or even maintaining the present level of demand for electricity should diminish considerably.

  • Comment number 49.

    "think of what was the 1950 uk citizen daily energy consumption ?"

    At last, an environmental campaigner confirms the agenda, they want us all to go back to life as it was in the 1950s.

    To reduce our CO2 levels, we need to build a dozen new nuclear power stations, and move to using that electricity for heating and cooking in the home and for powering personal transport (which could involve using electricity to produce hydrogen from water) which would also make us energy secure as it would reduce dependency on oil and gas which we mainly get from unfriendly nations.

    I know the environmentalists don't like nuclear power, and yes the sites would have to be well guarded to prevent a terrorist threat, but the choice is stark: Nuclear power or a return to the 1950s

  • Comment number 50.

    The folks at the Centre for Alternative Technology in Machynlleth worked this lot out 30-odd years ago! Their answer was to harvest both wind and solar power not to generate electricity but to heat a large tank of water, used as a year-round energy reserve to keep the house warm. In most parts of the UK, the vast majority of energy is used for heating (space heating and hot water) and this would make the most efficient use of natural energy resources. The problem, of course (apart from it not being a very 'sexy' solution) is that retrofitting a suitable water tank to existing houses is a bit of a headache - but sure not an insuperable one.

  • Comment number 51.

    Interesting article and I largely agree with the maths/calculations about large wind turbines versus small turbines.

    However the final assumption about energy consumption does not take into account the fact that we have to cut consumption of resources. That includes energy.

    My total energy consumption at home has been reduced by 60% over the last 3 or 4 years.

    My daily consumption of energy at home is about 6 and 20 kWh (depending on season).
    That includes heating, cooking, lights, TV, computer, fridge/freezer, washing machine, internet, kettle etc.

    eg. all mod cons.

    So how does anyone use 125kWh per day??
    The average UK person obviously has a lot to learn when it comes to management.

  • Comment number 52.

    "According to MacKay, it takes 40 kWh to drive the average car 50km."

    One horsepower is 750 watts, so 40Kwh = 53 horsepower-hours. An average at cruise uses about 20 horsepower or 15Kw to maintain 60 mph speed on a flat surface without headwind. 50Km is 30 miles, so this would be 10 horsepower-hours at 60Mph. The remaining 43 horsepower-hours must be the sum of warm-up, acceleration, and waiting at lights, which wouldn't change much for a trip like that, or the cost of extracting, refining, and distributing the fuel, which is far more likely.

    If an average car is 15' x 6' (90 square feet, or 8 square meters) then covering it with solar panels would supposedly yield 8 kilowatt-hours per day, at 5 hours per day average exposure and 20% conversion efficiency. The uninstalled solar panels would cost about $2.50 per watt, or $4000. 8000 watt-hours/750 watts per horsepower > 10 horsepower-hours.

    What one presumes, at this point, is that creating an electric car capable of driving 50 Km per day and recharging from solar panels would short-circuit the fuel extracting, refining, and distribution energy losses. Recharging the battery might waste half the energy (the chemical conversion process in charging a battery generates heat) so the solar panel dimensions and cost might have to be doubled to 16 square meters and $8000. Putting panels on the car has a number of problems, particularly if one keeps it in a garage, but there are plenty of stationary sites for situating the panels.

    Urban wind turbine installations have all kinds of problems and shouldn't be attempted. Solar panels, howerver, are very well behaved in an urban context. If people chose to use the solar-powered electric urban run-about option, it could cut transportation emissions by more than half.

  • Comment number 53.

    its obvious what the real problem is ,,education i live with solar and wind power and i dont use 125kwatts a day thats the problem peaple are pigs when it comes to electricity hair dryers toasters carving knives massive tellys huge american style fridges jauzzi baths the world gone mad is it still legal to make anything you want that uses electricity and sell it to the masses ,,,yes it is

  • Comment number 54.

    Interesting comments I agree with much of the scepitism about the "Dash For Wind"...
    Wind is an unstable, secondary source of power
    It causes visual and sound pollution all of it's own
    Tidal is better,
    Stable and predictable to the minute but there maybe problems caused by changing flows (See the impact of sea defenses on coastal erosion along the coast)
    Solar the source of all our non-nuclear power ..
    New Building regs all houses must have solar roofs. Production volume of Solar Panels soars, prices fall.
    Maybe not grand enough for the politicians?
    The Canary Islands .. European, bright, sunny, barren for the most part. Why not cover them in Photo-Voltaic arrays and pipe the output to the Euro Grid? Instead of Cash aid to sub-Saharan Africa PV Arrays enable them to become exporters of the oil of the future

  • Comment number 55.

    On the loss of 'views' comment. Remember that global warming (caused by humans or not) will lead to our countryside changing dramatically over the next century. I think I'd prefer having a view of a wind farm to having a view of a nuclear power station. Unfortunately many of the sites for new nuclear power stations are in the most beautiful and unspoilt parts of the country (3 sites approved on the edges of the Lake District National Park for example), well away from the urban and industrial centres where the power is needed.

  • Comment number 56.

    First, I think everyone now agrees that microwind in towns is a no-go, simply because the windspeeds are so low. However, don't write off large-scale wind power, particularly of the off-shore variety.

    Up here in Scotland, offshore wind turbines are producing 30-35% of their maximum capacity. That means to supply the UK with the 44 GW it requires (on average) would require ~133 GW of installed offshore windpower off the Western Isles (beyond sight of course!).

    Is this an impossible dream? Not really. The big turbines are currently rated at 6 MW each, with 10 MW units coming into production soon. Then we just need to plant 130,000 of them and that's all our electricity requirements met (*if* we could store it).

    On another note, it pains me that a lot of rubbish is spouted regarding how much electricity is required to run an electric car. This data is readily available from real-life usage of the many electric cars already out there. Essentially, an average sized car gets about 5 miles per kWh on the combined cycle (a bit more for a MiEV, a bit less for a Tesla). If we take post 34's figure of 537 g CO2 per kWh for current UK electricity generation, that equates to 67 g/km, which is less than any fossil fuel car on sale. 12,000 miles per year would add 2,400 kWh to your electricity bill each year. Off peak (charging at night), that costs about £144.

    A single 6 MW Atlantic wind turbine would produce 17,520,000 kWh per year, enough to run 7,300 family sized electric vehicles at 12,000 miles per year.

  • Comment number 57.

    I don't understand why we don't use water power more. We have a large number of rivers that tend to have their greatest flow in winter - just when we need the most domestic energy. I believe part of the answer lies in having lots of smallish sized undershot waterwheels. After all the same water will power a number of wheels down a stretch of river. The wheels can be massed produced and should be quite easy to fix to the river bank. Am I correct or have I overlooked something obvious - apart from the commitment to explore alternative supplies that is.

  • Comment number 58.

    Professor David MacKay (my old supervisor) will, like most competent physicists, be using kWh to measure energy and kW to measure power. (Not kWh to measure power as it says in this article.)

    And what kind of half-wit describes power in kWh per day? 20kWh per day is pretty much 1kW. (There are 24 hours in a day. Duh!) Why muddy perfectly clear units by changing halfway through an article?

    Perhaps this is the reason why the author briefly thought buying a micro wind turbine was a good idea: catastrophic inability to do elementary physics. Does the BBC not have even one scientifically competent journalist to write up (or at least copy edit) stuff like this? If you like you can send stuff to me and I will do it. Editing an article like this so it made sense would only take a competent physicist a couple of minutes.

  • Comment number 59.

    #17 - No, 'two out of three watts' are NOT lost during transmission, I don't know where those figures came from, but they are completely innacurate.

    #29 - Totally right, couldn't have said it better my self!

    To be honest, I'm shocked at the general level of incompetent reporting, and uninformed commenting by users who clearly do not have any real (or accurate) knowledge on the subject, but feel they are right anyway. Leave these problems to those who are trained to deal with them, and can analyse them correctly! Joe public does not automatically know more about electricity generation that a professional in that area just because there are more of them!

  • Comment number 60.

    The bottom line with alternative energies like wind and solar, is storage vs consumption, or in simple terms, supply and demand. You must have energy creating devices that can not only supply you with enough energy to consume on a daily basis, but it must also generate and store a surplus. If you are planning a home system for example, you would need enough batteries to disperse your daily consumption, while the devices are restoring the demand. To balance the system, either purchase alot of devices and batteries, or reduce your lifestyle to match the available resources. Should we construct all of these devices for public use, or purchase our own? Maybe we should ask, which is more beneficial, or which is least expensive? There is lots to consider. While major political figures and corporations are going ahead with some projects, others are lobbying against them, and people like you and me are doing things by ourselves. I need to save money in this world where everything goes up except wages. Should I spend my hard earned money to pay for utilities that I can create myself? Imagine a Power company, spending billions in previous profits, to make a new system that supplies 1 million citizens. They make $5 clear profit a month from each customer. Thats $60 million a year. Big business wants to keep you as a consumer. Imagine making your own wind/solar system and compare the cost, Its not all that promising........

  • Comment number 61.

    My view on this is that we need to start doing something, if there is no push to take up these technologies then there will be no funding for more research into efficiency.

    The statistics I would like to see are how long it would take to make back the energy used creating the turbines, if it would not make back that energy in its expected lifetime then it isn't worth it.

  • Comment number 62.

    Every time a wind turbine is connected to the UK grid to contribute energy, an equal amount of power must be made available from a piece of running conventional plant, increasing and reducing load as necessary as the turbine output varies, thus keeping the total load requirement reasonably constant.

    Thus the more turbines that are constructed & connected, the more power stations that must be kept running on expensive variable load, consuming huge amounts of fuel as they ramp up & down.

    Even if you could (although not practical) provide 100% of UK energy from wind power, you would still need to have available the same power availibility (100%) from conventional power stations, so why not just build them and run most at full load efficiency and forget the wind turbines altogether?

  • Comment number 63.

    have you seen the Stirling Electric sun powered turbines being built in New Mexico?
    the wind does not always blow and the sun does not always shine
    but the water always flows it seems that when the world went away from the water wheel it was permanent.I have a friend turning enough juice to run his whole dairy farm.from a water tower.

  • Comment number 64.

    Sue Doughcoup, the only reason we don't use hydro power in this country is a question of scale. For all the huge size of hydro-generation plants, they actually produce pretty limited amounts of power.

    New Zealand is a good example of a country where hydro-power works and produces a large chunk of their energy needs. However, the reason it works there is because while their land area and rainfall is comparable to the UK, they have only one twentieth of the population and energy needs.

    Furthermore, you need huge areas of land for reservoirs which in New Zealand are mostly uninhabited, while here the land is very crowded. Public opposition would be huge. Finally in the UK the rain falls mainly in areas where there is very limited population, resulting in losses while you move the energy to where your people need it.

    In summary hydro works for sparsely populated areas where there is lots of rain, and mountains. The UK is crowded, flat and (ironically) not actually even that rainy.

  • Comment number 65.

    about 2 years ago I sent an email to my local MP (ALAN DUNCAN) suggesting that every new build house should be made to have a couple of solar panels, his reply was that it would not be possible due to the cost to businesses (lol) wish I had saved both my email and his reply

  • Comment number 66.

    #62 your assumption that whilst one turbine needs an equal back up of conventional energy does not require scaling up as you suggest.

    On large scale wind farms the wind does not simply stop. The more widespread the wind generation the more predictable the power harvest becomes. Combine this with hydrogen production as done on the Norwegian island Utsera and there can be a net reduction in the need for large scale power stations on standby. Utsera successfully disconnected themselves from the mainland and use only wind generated power. They are now net exporters of hydrogen rather than net importers of national grid electricity.

    Combine this with other sources of power - such as tidal and the backup need can be vastly reduced.

    It really is about time all locks on our rivers were powered by turbines. A weir is only their to dissipate the kinetic energy stored in the higher water level needed for the lock. The energy is converted into a lot of noise and by spreading the water out to reduce the erosion of a narrow flow. Simply installing a turbine in one channel would produce plenty of local power, reduce noise levels and use a lot less space - without any downside.

  • Comment number 67.

    there are a few issues ussaly ignored by oponents of renuable energy sources.
    1 current enegry is nit generated form one cource so why espect a single technology to replace it?
    2 centralized production results in transport losses that are avoided by generating power where its used.
    3 cost the decrease in cost of modern technology compaired to the increase of fuel cost, add inflation to this and even current technology will be economical over its lifespan.
    4 independence once most (if now all) power is generated localy or within the country outside influences like oil prices will have little or no influence on the economy, also there is less chance money used to pay for oil is used too fund "groups who disagree with us"
    5 jobs; these turbines and solar panels (both foto electic as thermal) need to be made and as result create jobs; also the maintenance might be more labor intensive then current power plants so will create stable jobs.

    Even with current technology if all south facing roofs would be covered with a combination of foto electric panels and thermal solar panels a big part of the energy demand will already be met, even during clouwdy days while not adding any estetics issues or taking up any aditional space.
    Intergrating these panels into the roof at construction also removes the use for rooftiles ect and makes insulating the roof more economical especialy when the insulation is intergrated into the panels.

    The tools are already there l now they just need to be used.

  • Comment number 68.

    nuclear (fission now, fusion later) + wind + lots of four wheeled batteries.

    Simple, lets all stop getting in a tangle and get back to more important things like who's going to win the x-factor. dum de dum.

  • Comment number 69.

    Your equation connecting power, area, and wind speed is meaningless unless you state the units of the quantities involved. Power in HP or kW? Area in square feet or square metres? Speed in mph or metres/second? The proportionality factor 0.5 itself has dimensions because those of power are not those of area times speed-cubed.

  • Comment number 70.

    That's a lot of power, but even on quite conservative estimates the average UK resident uses 125 kWh day.
    This is misleading, this is all the energy used in the uk divided by the population.
    Otherwise we would have personal electricity bills of over £5,400 per year!
    This takes 12pence as the average cost per kw/h

    I think the writer should be more careful not to misrepresent his case.

  • Comment number 71.

    The idea that we can somehow reduce carbon emissions signficantly without very large changes in the way we live seems extremely silly to me. If, as jean michel urbani suggests, we in the developed world cut our energy usage to a fourth, or less, of what it is now (not just household, but all of the embodied energy in the products and services we use)then many things may be workable. Perhaps not micro-turbines, in their current state of technology, but slightly larger neighborhood ones. And perhaps we need to accept that electricity will not be available at the same level 24/7. This kind of change is daunting, but better to begin now, than to be forced into it(by events, not governments) later.

    I live in the wasteful, auto-addicted USA. My small northern city (Eau Claire, Wisconsin) has only the most rudimentary public transportation system (anyone in Europe would laugh at it). However, I got rid of my car a couple of years ago and find myself happier, healthier, and 20 lbs thinner as a result. Of course, it limits my lifestyle, and I don't like some of those limitations. But once I adjusted, the trade-off was worth it.

    Historically, people have lived well on a fraction of the energy that we in the developed West consume. Just do it--bite the bullet and make some significant changes--you will get used to it, you will set a grand example, and you may find that your life improves as a result.

    Zinnia44, Wisconsin USA

  • Comment number 72.

    Paulville - #51 - 125 kWh is the total energy consumption, including manufacturing, transport, heating, electricity etc. It's very easy to concentrate on home use alone when workplace energy use, transport and the stuff we buy use far more energy.

    Cant-make-it-up #62 - see my post #44: No need to worry, a wind turbine does not need 100% new backup. First the backup already exists and does not have to be built. Existing forms of generation are prone to outages (and these are less predictable and bigger than those from wind variations). By installing a wind turbine you are reducing fuel use in existing generation facilities. Because of this existing backup it's only once we get to 20% of electricity from wind that intermittency becomes a problem, and this point won't be reached until 30GW of wind power has been installed.

  • Comment number 73.

    Whilst I believe micro-generation is the way forward, we shouldn't forget the importance of location. On a more commercial scale - wind turbines in the 'roaring-forties' and photovoltaic panels in the deserts is surely a picture of the future?

    Meanwhile, hear on West Coast Aus a combination of both on every house seems the way to go!

  • Comment number 74.

    8 Jean points out the most efficient way of saving energy. Building better when we build.

    your concluding line isn't wrong it is just that some would wonder how it took you so long to figure out that there is no SINGLE solution.
    geo thermal heat pumps could help solar a bit more those savings in the building of structures doing the most.

    Every time someone says "this don't work" because it doesn't work where they live they are adding more fuel to the IDIOTS that think "nothing to see here"

    Micro wind turbines have powered hippes isolated retreat television etc for years.IF they live in an area of wind.Like inland Dorset for example.

    Dude most days there is wind....100 ft up in the air.
    Go fly a kite if you wish to see if there is wind around. Notice surface wind speeds are low but not very far up they build up.
    This is the basis of the emergency Kite sails used by some smarter sailors for when they have a catastrophic mast failure.

    Go see the few that are off the grid and do the math.

    They DO exist.

  • Comment number 75.

    What this article misses is another "inconvenient truth" about wind power. It cannot provide a base power supply. In an average year in the UK there are 3-4 days where the whole of the UK is at or close to still wind conditions (including the shallow coastal areas). It usually corresponds to a huge high pressure sat directly above the UK. Base power is the amount of power you have to provide at all times. Even if we used every large lake in the country for a pump storage scheme, that would only flatten out the first 12 hours of a dead calm. So this means the cost of wind power is increased by the fact that you still need to build and maintain other power stations to deal with the variability of the wind. This is expensive both financially and in energy terms. The same is true of many renewables (solar and wave power for example). If you want to use renewables, you have to look at hydro-electric, which is already very exploited in Britain, tidal or geo-thermal, which is currently not really feasible in Britain.

  • Comment number 76.

    dave_h #75 - see my comment #72.

    Also, remember that baseload is an artificial straight line, which was a useful concept fifty years ago when bigger machines were more efficient and grid control systems were limited. With today's technology we can focus on satisfying (and/or adjusting) demand. In Spain the concept of a single group of core generators providing a more or less constant baseload has been abandoned (I know this from my meetings with the Spanish grid operator and various utilities in Spain). This is the future of grid control. All forms of generation are unreliable in their own ways, but we now have the skills and technologies to cope with this (or we will once we've caught up with the Spaniards and the Portugese..).

  • Comment number 77.

    Unfortunately, Power = 0.5 * collection area * (wind speed)^3 is wrong. The correct equation is Power = 0.5 * density of air * collection area * (wind speed)^3.

    It only increases any of your calculations by .23 (at sea level) at most, so it doesn't harm the conclusion you draw, but it is important to provide the correct information.

    You can double check this by doing simple dimensional analysis. The equation you posted resulted in distance^5/time^3, which is not mass*distance^2/time^3 (= Power)

  • Comment number 78.

    #1 You are passing what you call exhorbitant costs straight to the user who you want to be more green! Not everone can afford to do that.

  • Comment number 79.

    Hydrogen is not a fuel, it has to be created to be used, rather like electricity. It does not exist in a usable form.
    It can be regarded as a transmission medium.

  • Comment number 80.

    Maybe we are on the wrong track entirely. Why is everyone focused on reducing CO2 when the individual contribution is only a small part of the global CO2 inventory?

    The CO2 eating capacity of the planet is reduced daily in the rain forests around the equator. Look at the graphs of CO2 concentration over time. It stair steps with the summer-winter cycle in the land dominated northern hemisphere. What has changed is the year-round benefit from the tropical equator. The rain forests are a small fraction of what they were 50 years ago.

    Reclaiming the rain forest seems like a much more achievable solution to the challenge.

    We can also look at the oceanic processes that absorbed the CO2 dominant atmosphere a billion years ago. Releaf may come in the form of algea.

  • Comment number 81.

    I am in favour of Nuclear Power but the current perspective appears to be that there may not be enough fuel to go around as the world takes nuclear on, more and more.

    We may well have to invent or create new sources of fuel.

  • Comment number 82.

    We seem to be thinking on one side of a great wall. The debate appears limited to deciding between what works poorly (wind power) and what works dangerously well (nuclear power). Wind power enthusiasts rarely mention the addition capacity that must be built to accommodate the natural lulls in generation; nuclear power advocates absolutely never mention what will be done with the radioactive waste that results from nuclear power generation. So we keep arguing, all the while changing nothing.

    The other side of this wall is extreme conservation. Anyone who has been in a dark area has seen the surreal lights in the sky above any urban area; how many of those lights are needed? Can anything be done to manage them, such as movement sensors? As for cars, very few places have required car pooling. Homes can be efficiently heated by pellet stoves, whose particulate output is, on average, less than two grams per hour, and whose carbon generation is 90% less than oil combustion. Every home should be given a loan to purchase and install a pellet stove, which can be paid back within one year from the savings accumulated by burning pellets rather than home heating oil.

    These are just some ideas. The area of extreme conservation has not been explored in the international debate at all. It's time it gets equal time with the advocates of increased production.

  • Comment number 83.

    I work in the wind industry - so may be biased!

    One must look at turbines now compared to 20 yrs ago - with significant funding the more and more poweful, reliable and intelligent they become, so it is wrong to base the theories that the author does that it is simple size and location.

    We (the wind industry) are producing turbines that 15 yrs ago we could never have installed before, ie, low wind areas, high turbulance areas and populated areas (we have turbines that produce low noise).

    Also, the big drive at the moment is quality, ie, making sure they do not break down - and this can only be improved with orders and demand.

    With regard to the future, who is to say what is and is not possible when it comes to locating turbines - ie, mid atlantic?!!!

    Main problems are NIMBYs (not in my back yard). I often see wind farm projects stopped due to this - if it was up to me I would let the town lose all power for 1 day, I think they would change their mind, as this will happen one day as we do not have an infinite amount of fossil fuel.

    Just think that at 2am tonight, all over the world giga watts of power is being produced from simple wind, no Co2, no pollution - how can we dare we be critical on this?

  • Comment number 84.

    I live in the Texas panhandle, where wind farms are springing up all around. Winds around my house run around 10 mph for the norm, and a windy day will see winds in excess of 30mph. The very wind we used to curse for making our lives miserable, we now consider a blessing as it is bringing in jobs with a future to a region that has been slowly dying.

    I am within walking distance of one very large, and still growing, wind farm. In fact, I walk my dog through the wind farm on a daily basis, and despite the handwringing and moaning of those who haven't ever actually seen a wind farm in action, there are not growing mounds of bird carcasses amassing beneath the turbines. In fact, the only dead thing I've seen out there was a mangy, starved coyote. We are directly on the path of migratory ducks and geese... they pass overhead by the thousands and they pass low, often landing in the surrounding corn and milo fields... yet none seem to come into contact with the turbines. Perhaps birds are a little more clever about avoiding things the size of an aircraft carrier than some give them credit for?

    I am beginning to see personal turbines crop up, though they are pole mount vs roof mount, and the owners have been pleased for the most part. Perhaps personal wind generators are not feasible worldwide, but in areas like ours, where the wind never stops, they are definitely the future.

  • Comment number 85.

    The sun radiates energy in 1 hour what the human specie uses in a year.

    We cant store that energy? NONSENSE!!! yes we can.

    It can be used to compress air into cylinders for vehicles or generators and it can be used to split water so hydrogen can be burned for generating electricity. Wind energy harvesting is part of the whole picture.

    I have heard all the lobby puppets excuses against this common sense and I am sick of their time wasting.

    It is now time I think to legally deal with man made climate change deniers the same way that holocaust denial is treated.

  • Comment number 86.

    Oh and to the nuclear lobby which drones on about how wonderful the energy is from the by product of the nuclear weapon industry I have only to say this:


    There is a reaction going on for free called the sun. It is clean and it needs no maintenance and there is no contamination of the environment from it. So forget Nuclear Power Stations... they are RUBBISH.

  • Comment number 87.

    These kinds of analyses are nonsenses. This one is particularly skewed. One can get lost in numbers and persuade oneself of all kinds of fantasies if one is so inclined. The truth is far simpler:

    We live on the solid crust of a planet floating about 93million miles from an unimaginably collossal nuclear reactor called the Sun. The crust is far thinner than the shell of an egg, to scale, and is divided into plates that slowly float around on the surface of the Earth. Really, our biosphere is an organic scum almost invisibly minute, coating our world. That ball is mostly semi-liquid flaming hellfire, and were it not for that delicate skin of rock, we'd all be toast in a second.

    A hair's breadth above us is the Ozone layer. A tiny segment of the atmosphere that prevents radioactive blasts from the nearby Solar furnace from blinding us all with everything from Ultraviolet to Gamma radiation. Raging around the planet is a cosmic microwave oven of all kinds of furious energies, and without those protective layers of the air, we would all be fried to cinders, much as someone might be had they decided to go sunbathing in the core of a nuclear power station.

    So in short, we are a tiny layer of organic scum sandwiched between a planet-sized raging ball of hellfire and a vast cosmic nuclear furnace. And someone, somewhere, a miniscule voice is saying "I think we have a shortage of energy". How evolved and smart we have become!

  • Comment number 88.

    #84 Jadalina.

    That's damn right.

    The analysis in this report is nothing more than whining. Energy is in abundance - it's just that either people will have to start moving to where the sun and wind is, or they'll have to pay to have it piped in.

  • Comment number 89.

    I think this article is misleading. Wind power has never been thought to be sufficient to meet all human energy needs. The fact that 48kWH per person could be provided is an extremely positive thing, not a disappointment as this article implies. My household of 2 adults uses 20kwH per day for non-heating non-transportation needs

    The implicit and unstated assumption in the article is that more has been expected or assumed possible from wind power. If the writer believes this, some defense and background for this assumption should be given.

  • Comment number 90.

    One comment, has anyone noticed how ugly wind turbines are ? and wouldn't one solution be population control, albeit vendors of various consumer items would not make as much money with a smaller population to sell to ?

  • Comment number 91.

    "According to MacKay, it takes 40 kWh to drive the average car 50km."

    A liter of gasoline is 32 mega-joules (MJ). A joule is otherwise known as a watt-second, and also as the scientific version of calorie (the dietary calorie is 1000 of the chemical version).

    Dividing 32,000,000 by 3600 yields roughly 9000 watt-hours or 9 kilowatt-hours.

    40 kilowatt hours would be 4.5 liters of fuel, times 11 kilometers per liter (a 1.8 liter engine with an automatic transmission).

    Less than 20% of the energy contained in the fuel is used to actually move the car down the road. More than half the energy is simply radiated into the atmosphere as heat. Half of the remaining energy is consumed by friction, either within the engine and transmission components, air resistance, or tire traction.

    In such circumstances urban areas are best served by electric cars or other electric vehicles charged with solar power. More rural areas have the ability to use cars burning locally produced propane, natural gas, or biodiesel. All of this is capital intensive, but technically possible.

  • Comment number 92.

    There is no anthropogenic global warming. All of the original Koyoto Protocol AGW theories have been proven wrong. The famous Al Gore "hockey stick" curve is a proven fraud. The "debate" is NOT over and real science will not be swept under the carpet. Plans for trillion dollar carbon credit trading will eventually be exposed as the greatest scam and public deception in history.

    Oil, gas and coal are cheap and abundant and we would be utterly stupid not to continue to use them. Real technology such as nuclear fusion (not fission) will eventually replace fossil fuels - only a few hundred years ago we had no electricity and no oil - so those who think that we will not naturally move beyond this technology are simply not wired up right. The stoneage did not end due to a lack of stones and the oil age will not end due to a lack of oil - but fools painting CO2 as pollution are not helping anyone except themselves. We should not be subsidising development of futile technology - science does not advance by consensus but genius is certainly stifled by it.

  • Comment number 93.

    The problem with oil is that you can only buy it using dollars.

  • Comment number 94.

    I think the folks who are in favor of nuclear power should do a reasonable study of the availability of uranium. It is attractive to some metals investors because of its scarcity. Thorium is considerably more abundant, but I don't have any idea how long it would take to get a thorium-based nuclear plant approved, built and ready to produce power.

  • Comment number 95.

    Thank you for caring, for bothering, and for trying.

    Crucially, every little bit does in fact help. Just as the problem itself is the result of quintillions of decisions and actions originating in billions of human lives, so the climbdown towards survival will involve quintillions -- and more -- of contributions, great & small.

    No, it need not at all be about: "Don't do this" and "forget that."

    It will be about doing more with less, reducing, thinking -- milking the moment, occasion, opportunity for everything it's worth.

    It will be about taking one holiday to an island paradise, instead of three a year -- and enjoying it more, by being less jaded.

    It will be about standing up for something as radical as file-sharing, because actually it leaves a considerably smaller carbon footprint than the marketing of solid, shrink-wrapped content to single households.

    It will be about something as unimaginably difficult as having more sex rather than watching more porn.

    It will be about having a ready excuse that actually means something for not showing up to all those gatherings you would really rather skip...

    It will be about drinking a higher-quality beverage less frequently than a cheaper drink, for the simple reason that you feel guilty about the waste, the extra packaging, the fuel involved in the distribution logistics -- and so you reward yourself by upgrading to a single-malt you love, to make up for denying yourself the cheap booze you used to get wasted on two or three times a weekend. Less booze = less retching = less watercloset use: yes, even down to that level of detail.

    Or it might be about the realisation that you really don't want any more offspring, and so you might as well just get sterilised, after all, and stop wasting a bundle, year after year after year, on contraception you don't really need.

    Or it might be about allowing yourself the luxury of giving up fast food, junk food and cheap eats in exchange for higher-quality fare that supports the local economy as well as helping the environment -- not to mention your own health & well-being.

    In other words, it needn't be difficult at all.

  • Comment number 96.

    To 8. jean michel urbani

    Jean Michel, your English is great (I'm a teacher)

    Your views too. I'm sick of detractors of these 'less easy than fossil fuels' alternatives. Any way we can reduce out reliance on oil, gas - and nuclear - energy is surely a good thing and needs to be financially supported.

    But if birds are also being killed, that's something that needs to be looked out, taken into account, and remedied where possible.

    As for the 4x4 housewives, it's time government took a stance on wanton polluters - be they business or private.

  • Comment number 97.

    As the inventor of a new wind turbine thats in the 10 megawatt class and 800+ foot, I do agree the smaller towers for turbines don't get into the free air enough for most to get a decent payback period if at all due to teh lack of wind speeds available.

  • Comment number 98.

    A wind turbine in Camden! I cannot think of a more unsuitable site, your in the middle of one of the largest conurbation in Europe, with lots of buildings to break up the wind. You need to get out more, its not nonsense to suggest that 4% of all the UK's electricity could come from Micro Wind generation if you live either near the coast, Scotland, North of England, Wales, Northern Ireland or the West Country, i.e. half the UK land mass. So because it does not work in London you suggest "the government should think again about offering a generous feed-in tariff for power generated from micro wind turbines" The purpose of these feed-in tariffs is kick start an industry, so the high installation costs come down over time in areas with good wind speeds. This is typical a London based journalist jumps to a conclusion that is only relevant to inland regions of central and southern England.

    There's been a series of these attacks on Wind power recently, a lot this originates in the Nuclear lobby. There have been wild per kWh cost estimates for wind, while Nuclear cost estimations are accepted despite decades of budget over runs and delays on every plant built. You cannot insure a Nuclear plant, so every one build has an indirect Tax payer subsidy, with the waste liability passed on to future generations. Carbon capture is another bit of dodgy economics that we are being ask to back despite the fact that UK coal output is only 15m tons a year. Nobody has any real idea how much CCS will cost yet.

    Nuclear and some big generators are scared of Wind power and the feed-in tariffs as every Tom Dick and Harry who can find a windy site can put one up, i.e. a real market that the generators cannot monopolies with a few very large power stations. When you combine Wind with Hydro (soon from Norway), Pump storage,and Natural Gas which can be brought up quickly (unlike Nuclear or Coal) you cut your fossil fuel input and carbon output substantially. As wind has the cheapest running costs, that's used first and then Gas, which will soon have enough capacity to supply 50% of our electricity.

    You need to be very careful with some of these cost estimates, for example, the Royal Academy of Engineering came up with cost estimate for Nuclear that was as cheap as Natural Gas, that is just not realistic, as the new Nuclear plant in Finland est 3 billion euro now going be nearly 6 billion and 3 years late. The Nuclear industry are after Loan guarantees and carbon Tax (Subsidy)to add to the decades of subsides and bailouts they have already had; hence the attacks on wind and reports the EU are going to turn the lights out.

  • Comment number 99.

    I would be more impressed with all the environmentalists if they actually lived their creed. Wealthy environmental leaders like Gore who travel on private planes, live in large houses with huge carbon footprints etc really do not cut it in terms of persuading anyone they mean what they say. Similarly scientists who will falsify data, conspire to make certain that contrary results are not published, and exchange tips on "tricks" to create misleading graphs falsely implying global warming do not really cut it in terms of persuading anyone that they mean what they say. People with multi-children families writing editorials demanding that government enforce one child per family policies are similarly unpersuasive. I see it as sort of like religious persuasion. One "Christian" who actually lives out the creed is a hundred times more persuasive than a hundred "preachers" who live inauthentic and un-Christian lives. Same deal for environmentalists. Most of them seem like busybodies eager to have other people do the work and pay the taxes to do things they don't do for themselves.

  • Comment number 100.

    Justin, have you considered vertical wind turbines? They produce more energy in less wind, take up very little room, fit most residences, and come in a variety of esthetically pleasing shapes and sizes. They are much more efficient than standard long blade turbines.

    Just Google vertical wind turbines and you'll see a wide variety of vendors.


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