Several electricity supply companies are planning to launch schemes in which customers would sign contracts specifying that all their power came from renewable sources like the wind, water and methane gas generated by rotting garbage. These customers would pay a premium price - perhaps as much as 10 per cent higher than ordinary bills.
The new thinking was unveiled at a major conference on global warming in London yesterday organised by the World Wide Fund for Nature (WWF). The fund is interested in auditing and endorsing such schemes, ensuring they actually boost renewable energy over polluting fossil fuel power stations.
Electricity companies are interested in being able to use WWF's famous panda logo to help sell the scheme.
The opportunity arises because from 1 April next year the local monopoly of regional electricity companies will end. Any household will be able to buy power from any generator, anywhere.
Electricity from renewable and conventional sources is mixed on the grid. So the trick, as far as the companies and WWF are concerned, is to devise a "matching" system. This would assure customers who sign up for green electricity that their consumption, year on year, will be matched by extra consumption of renewable energy in the grid as a whole, over and above that which would have happened in any case.
All UK electricity consumers already pay a small levy on their bills - less than 1 per cent - under a government devised scheme to promote renewable energy. This has worked well, in that the number of wind turbines and other green power sources has grown rapidly.
However, next year this subsidy expires for more than 300 megawatts of renewable energy capacity spread out over dozens of small forces, like wind farms. Some are in danger of closing as a result, which would lead to increases in pollution as fossil fuel power took over from them.
Customers pledged to buy green power could, however, keep them going while persuading generators to invest in new renewable energy sources.
Sue Gill, of Green Electron, a subsidiary of West Country electricity company SWEB, said "It's a niche market but one worth pursuing." Her company is hoping to launch a nationwide green electricity scheme next year.
Dr Merylyn McKenzie Hedger, climate change policy co-ordinator with WWF, said any scheme would need rigorous auditing to ensure customer demand to buy only green power had been fully matched with renewable energy generation. Michael Meacher, the environment minister, told the conference Britain would not deliver on its new target of cutting carbon dioxide emissions by 20 per cent by 2010 if other European Union nations did not go further in curbing greenhouse gas emissions.
The EU has worked out a complex deal on cutting greenhouse gases which allows some of the poorer, less industrialised countries like Portugal to have big increases in their emissions between 2000 and 2010. Europe as a whole is committed to cuts of at least 10 per cent by 2010, making it the leader in the industrialised world.