The country already gets 16% of its electricity from wind, solar and other renewable sources – three times' higher than the level it had achieved 15 years ago.

"A complete conversion to renewable energy by 2050 is possible from a technical and ecological point of view," said Jochen Flasbarth, president of the Federal Environment Agency.

"It's a very realistic target based on technology that already exists – it's not a pie-in-the-sky prediction," he said.

Thanks to its Renewable Energy Act, Germany is the world leader in photovoltaics: it expects to add more than 5,000 megawatts of photovoltaic capacity this year to reach a total of 14,000 megawatts. It is also the second-biggest wind-power producer after the United States. Some 300,000 renewable energy jobs have been created in Germany in the last decade.

The government has set goals for cutting greenhouse gas emissions by 40% between 1990 and 2020, and by 80-85% by 2050. That goal could be achieved if Germany switches completely to renewable sources by 2050, Flasbarth said.

About 40% of Germany's greenhouse gases come from electricity production, in particular, from coal-fired power plants.

Flasbarth said the Environment Agency's study found that switching to green electricity by 2050 would have economic advantages, especially for the vital export-oriented manufacturing industry. It would also create tens of thousands of jobs.

"The costs of a complete switch to renewables are a lot less than the costs to future generations that climate change will cause," he said.

Last month a report by the UK's Centre for Alternative Technology in Machynlleth, mid Wales, said Britain could eliminate all its carbon emissions by 2030 by overhauling its power supply.

guardian.co.uk