Before Germany decided to shutter its 17 nuclear power plants by 2022, few had ever heard of Hotzenwald, a nature preserve at the southern tip of the Black Forest, in the prosperous state of Baden-Württemberg. Now, as the government retreats from nuclear energy in favor of renewables, many will watch this bucolic spot as the testing ground for Germany's ambitious green future.

And there is already trouble in paradise. Local Greens party leaders and residents are fighting a plan to transform a ridge overlooking the Swiss Alps into a hydropower electricity storage facility – a project that would destroy hundreds of acres of natural splendor.

"If you slice the top of a mountain and empty it like a breakfast egg, it's such an assault on the landscape that you jeopardize the very existence of this area," says Greens party parliamentarian Ruth Cremer-Ricken from nearby Bad Säckingen.

But experts say the €1.2 billion ($1.7 billion) storage project is a crucial piece of Germany's energy transformation. "It may be a problem for nature, but we have to decide what we want. If we don't build it, we won't be able to have more renewable," says Frank Musiol of the Baden-Württemberg Center for Solar Energy and Hydrogen Research in Stuttgart.

German Chancellor Angela Merkel's energy policy has undergone a dramatic about-face. Last fall, her center-right coalition reversed a previous government plan to ditch nuclear power. But Germany's visceral aversion to nuclear power, which has been an intricate part of German identity since the 1970s, gaining steam after the 1986 Chernobyl disaster, grew in the wake of Japan's Fukushima nuclear accident. And Ms. Merkel was swayed to wean one of the world's biggest economies off its nuclear supply. The government cemented the move in a late June vote.

But from Bavaria to Lower Saxony, opposition to green energy technology (often from the Greens themselves) looms as a major roadblock.

"We have the historic chance to set an example that this transition is possible, and how it can be done. If we don't succeed, why should anybody else embark on this path?" says energy expert Marcel Viëtor at the German Council on Foreign Relations in Berlin. "The harm would be great on a global level. But if Germany proves it can manage this energy turnaround technically, quickly, and in a way that strengthens its economic competitiveness – and we are optimistic about that – this might send a strong motivating signal to other societies."

This spring, Merkel inaugurated Germany's first offshore windmill farm, in the Baltic Sea. The 21-turbine park, set to provide electricity to 50,000 homes, will be a cornerstone of her plan, which aims to double the portion of energy generated by renewables to 35 percent by 2020. Currently, nuclear power generates 25 percent of Germany's energy supply.

The windmill opposition

Baden-Württemberg's top government official and Germany's first Green state premier, Winfried Kretschmann, says he wants to boost renewables but seeks a "quiet revolution" to reconcile both environmental and economic interests. But that is already proving difficult. For instance, in Münstertall, a village in Baden-Württemberg, locals have formed the Energy and Landscape Protection citizens' initiative to fight plans to build at least four big wind turbines.

"Baden-Württemberg always said, 'We don't need [wind energy], we don't want it,' " says Frank Musiol of the Baden-Württemberg Center for Solar Energy and Hydrogen Research. "Now people say we want wind energy but not in our backyard."

In 2000, Germany created conditions for the green sector to grow. It set an attractively high price at which it would buy surplus electricity from wind turbines and solar panels. This helped triple consumption rates of renewable power from 3.8 percent to 11 percent in 2010. Investment in the sector grew more than 75 percent in the past five years, more than almost anywhere else in the world, says Lutz Weischer of the World Resource Institute in Washington. Today, the industry supports 340,000 jobs.

But in Baden-Württemberg, home to both Daimler and Porsche, the nuclear industry is an economic pillar. And critics of Merkel's plan say shutting off reactors by 2022 will cost jobs, jeopardize the country's energy supply, and make Germany reliant on energy from France (the world's biggest nuclear power producer).

"How will the international competitiveness of German industry be guaranteed?" Hans-Peter Keitel, president of the powerful Federal Association for German Industry, wrote to Merkel.

More coal-fired plants

Critics also say the nuclear fade-out will hurt Germany's ambitious carbon-reduction goals, too. Until green energy can make up for nuclear's shortfall, Merkel wants to build new gas and coal-fired plants over the next 10 years, potentially producing billions of tons of greenhouse gases.

When its nuclear plant, one of four in Baden-Württemberg, shuts down, the town of Neckarwestheim, near Stuttgart, stands to lose 250 jobs and huge tax revenues. But the 3,500-inhabitant community is showing signs of thinking green, budgeting €50,000 ($71,000) to install solar panels on its new cultural center.

A local farmer, Alexander Geuß, did not give his vote to the Greens, who scored a historic victory in Baden-Württemberg, but he still wants nuclear energy's end. Nestled in the Black Forest, his village, Sulzburg, sits next to two nuclear plants that could burn long after Germany has taken its own off the grid: one in Leibstadt in Switzerland, and the other in Fessenheim, France, that country's oldest nuclear plant. "We are surrounded by it, the problem is everywhere."

He has no sympathy for Hotz­en­wald's hydroelectric reservoir opponents. "Nothing is pain free," Mr. Geuß says from his farmhouse. "If you want to produce more energy you have to be able to store it."

"A lot of hope has gone in those elections; now it's time to get down to business. It is not easy, but if we never start this discussion we will never arrive anywhere."