A tiny village in a wind-swept corner of eastern Germany seems an unlikely place for a revolution.
Yet environmentalists, experts and politicians from across the world have flocked to Feldheim, home to just 145 people, in the past year to learn how it is already putting into practice Germany's vision of a future powered entirely by renewable energy.
Chancellor Angela Merkel's government passed legislation in June setting the country on course to generate a third of its power through renewable sources - such as wind, solar, geothermal and bioenergy - within a decade, reaching 80% by 2050, while creating jobs, increasing energy security and reducing harmful emissions.
The goals are among the world's most ambitious, and expensive, and other industrialised nations from the US to Japan are watching to see whether transforming into a nation powered by renewable energy sources can really work.
In June, the nation passed the 20% mark for drawing electric power from a mix of wind, solar and other renewables. That compares with about 9% in the United States or Japan - both of which rely heavily on hydroelectric power, a source that has long been used.
Expanding renewables depends on the right mix of resources, as well as government subsidies and investment incentive - and a willingness by taxpayers to shoulder their share of the burden. Germans currently pay about £130 a year for a typical family of four to support research and investment in and subsidise the production and consumption of energy from renewable sources.
That allows for homeowners who install solar panels on their rooftops, or communities like Feldheim that build their own biogas plants, to be paid above-market prices for selling back to the grid, to ensure that their investment at least breaks even.
Critics, like the Institute for Energy Research in Washington, maintain such tariffs put an unfair burden of expanding renewables squarely on the taxpayer. At the same time, to make renewable energy work on the larger scale, Germany will have to pour billions into infrastructure, including updating its grid.
Key to success of the transformation will be getting the nation's powerful industries on board, to drive innovation in technology and create jobs. According to the environment ministry, overall investment in renewable energy production equipment more than doubled to £22 billion in 2011. Solid growth in the sector is projected through the next decade.
Some 370,000 people in Germany now have jobs in the renewable sector, more than double the number in 2004, a point used as proof that taxpayers' investment is paying off.