Tuesday 26 September, 2000
The Power of Hydrogen
Rising international oil prices and the public protests across Europe have raised the profile of alternative energy sources. Oil supplies are limited and recent events have shown how dependent the world is on oil based fuels to keep it running. In addition, most scientists agree that global warming is increasing largely because of carbon dioxide produced by burning fossil fuels. Matt Zepf of BBC Science reports on the prospects for hydrogen powered cars that emit no pollution.
The Ultimate Energy System
Hydrogen is the "ultimate energy system" for the future. At least that is what scientists attending the recent Hyforum 2000 meeting in Munich thought.
The idea is compelling. Solar power or other carbon free renewable energy sources would be used to generate electricity. This is used to generate hydrogen from water, which in turn is used to power cars. The potential benefits are enormous - no exhaust fumes and no greenhouse gases coming from car exhausts. Some companies are taking this technology very seriously. The car manufacturers BMW plans to produce the first hydrogen powered cars for sale by 2005. However, Detlef Frank, senior vice president of BMW, still sees some problems ahead.
‘We can only succeed with hydrogen if we manage to make it affordable. Affordable means that a normal household can afford this kind of energy, let's say, in the same order of magnitude as fuels of today.’
| 'Hydrogen can be a dangerous explosive and the thought of carrying large amounts in the tank of a car could be a bit disconcerting' | |
Explosive Results
Of course price isn't the only issue with this new technology. Hydrogen can be a dangerous explosive and the thought of carrying large amounts in the tank of a car could be a bit disconcerting. But Detlef Frank believes the dangers of hydrogen are no greater than many other hazards of daily life:
‘The danger is not higher, it is different. Hydrogen is a gas that is 18 times lighter than air. So if you have a hole in your tank, for example, it just evaporates straight up. If you have a hole in a tank of, let's say, a diesel truck, you will find a little lake under your vehicle. If you are in an accident and this burns then you will be in a very bad condition. So it depends on the type of accident you have.’
Bearing the dangers in mind Frank outlines the work still to be done:
‘The main technical challenge is the storage, as it needs to be stored at very low temperatures. We have tanks where we can store it at low temperatures, but that is still very expensive today. We have to reduce the costs of those tanks. We have to develop automated refuelling stations, because you cannot give a filler nozzle with minus 250c into the hands of a customer, because they would be burnt. And we have to work out a distribution system, be it pipelines, be it trucks, which is technically not a real problem.’
Production
Frank is very optimistic that the technological problems of hydrogen storage can be solved. But there is another problem - hydrogen production. Even though it is easy to produce hydrogen from water, it requires a huge amount of electricity.
‘So the real question is how do we make electricity? We have to produce hydrogen from renewable energy; otherwise we may make a mistake. If you make hydrogen from coal, then you do not do any good to the environment.’
It seems that green fuel technology is no longer a pipe dream. Large manufacturers are laying the foundation for a petrol free future for our cars. But in order to produce the large amounts of hydrogen, more effort will be required in developing renewable energy sources, such as solar power, and that may take some time yet. |
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| Pollution v Accidental Death |
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| In 1999 a report produced by the World Health Organisation showed that long-term air pollution from cars in Austria, France and Switzerland resulted in an extra 21,000 premature deaths per year from heart disease or respiratory illness. This figure is higher than the three countries combined figure for deaths caused by road accidents. |
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| Emissions |
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| It is estimated that more than 70% of the power used and half of the gases causing global warming are emitted from heating buildings and driving cars. |
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