It’s been a long, dark winter in Germany. In fact, there hasn’t been this little sun since people started tracking such things back in the early 1950s. Easter is around the corner, and the streets of Berlin are still covered in ice and snow. But spring will come, and when the snow finally melts, it will reveal the glossy black sheen of photovoltaic solar panels glinting from the North Sea to the Bavarian Alps.

Solar panels line Germany’s residential rooftops and top its low-slung barns. They sprout in orderly rows along train tracks and cover hills of coal mine tailings in what used to be East Germany. Old Soviet military bases, too polluted to use for anything else, have been turned into solar installations.

Twenty-two percent of Germany’s power is generated with renewables. Solar provides close to a quarter of that. The southern German state of Bavaria, population 12.5 million, has three photovoltaic panels per resident, which adds up to more installed solar capacity than in the entire United States.

With a long history of coal mining and heavy industry and the aforementioned winter gloom, Germany is not the country you’d naturally think of as a solar power. And yet a combination of canny regulation and widespread public support for renewables has made Germany an unlikely leader in the global green-power movement—and created a groundswell of small-scale power generation that could upend the dominance of traditional power companies.

Twenty years ago, it was clear solar power wasn’t going to get anywhere by itself. Photovoltaic panels were expensive and inefficient. Even solar systems designed to heat water, a far less technologically tricky task, were bad buys on the open market. Producing electricity from sunlight costs 10 times more than generating power using coal or nuclear energy. “The early systems might as well have been made out of gold,” says David Wedepohl, a spokesman for Germany’s Solar Industry Association.

In 1991, German politicians from across the political spectrum quietly passed the Erneuerbare Energien Gesetz (renewable energy law), or EEG. It was a little-heralded measure with long-lasting consequences.

The law guaranteed small hydroelectric power generators—mostly in Bavaria, a politically conservative area I like to think of as the Texas of Germany—a market for their electricity. The EEG required utility companies to plug all renewable power producers, down to the smallest rooftop solar panel, into the national grid and buy their power at a fixed, slightly above-market rate that guaranteed a modest return over the long term. The prices were supposed to balance out the hidden costs of conventional power, from pollution to decades of coal subsidies.

Investors began to approach solar and wind power as long-term investments, knowing there was a guaranteed future for renewable energy and a commitment to connecting it to the grid. Paperwork for renewables was streamlined—a big move in bureaucracy-loving Germany. The country invested billions in renewables research in the 1990s, and German reunification meant lots of money for energy development projects in the former East.

Now German companies lead the world in solar research and technology.

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