This story appears in the November 2015 issue of National Geographic magazine.

Hamburg knew the bombs were coming, and so the prisoners of war and forced laborers had just half a year to build the giant flak bunker. By July 1943 it was finished. A windowless cube of reinforced concrete, with seven-foot-thick walls and an even thicker roof, it towered like a medieval castle above a park near the Elbe River. The guns protruding from its four turrets would sweep Allied bombers from the sky, the Nazis promised, while tens of thousands of citizens sheltered safely behind its impenetrable walls.

Coming in at night from the North Sea just weeks after the bunker was finished, British bombers steered for the spire of St. Nikolai in the center of the city. They dropped clouds of metallic foil strips to throw off German radar and flak gunners. Targeting crowded residential neighborhoods, the bombers ignited an unquenchable firestorm that destroyed half of Hamburg and killed more than 34,000 people. Towering walls of fire created winds so strong that people were blown into the flames. Church bells clanged furiously.

The spire of St. Nikolai, which somehow survived, stands today as a mahnmal—a memorial reminding Germany of the hell brought by the Nazis. The flak bunker is another mahnmal. But now it has a new meaning: An urban development agency (IBA Hamburg) and the municipal utility (Hamburg Energie) have transformed it from a powerful reminder of Germany’s shameful past into a hopeful vision for the future.

In the central space of the bunker, where people once cowered through the firestorm, a six-story, 528,000-gallon hot water tank delivers heat and hot water to some 800 homes in the neighborhood. The water is warmed by burning gas from sewage treatment, by waste heat from a nearby factory, and by solar panels that now cover the roof of the bunker, supported by struts angling from the old gun turrets. The bunker also converts sunlight into electricity; a scaffolding of photovoltaic (PV) panels on its south facade feeds enough juice into the grid to supply a thousand homes. On the north parapet, from which the flak gunners once watched flames rising from the city center, an outdoor café offers a view of the changed skyline. It’s dotted with 17 wind turbines now.

Germany is pioneering an epochal transformation it calls the energiewende—an energy revolution that scientists say all nations must one day complete if a climate disaster is to be averted. Among large industrial nations, Germany is a leader. Last year about 27 percent of its electricity came from renewable sources such as wind and solar power, three times what it got a decade ago and more than twice what the United States gets today. The change accelerated after the 2011 meltdown at Japan’s Fukushima nuclear power plant, which led Chancellor Angela Merkel to declare that Germany would shut all 17 of its own reactors by 2022. Nine have been switched off so far, and renewables have more than picked up the slack.

What makes Germany so important to the world, however, is the question of whether it can lead the retreat from fossil fuels. By later this century, scientists say, planet-warming carbon emissions must fall to virtually zero. Germany, the world’s fourth largest economy, has promised some of the most aggressive emission cuts—by 2020, a 40 percent cut from 1990 levels, and by 2050, at least 80 percent.

The fate of those promises hangs in the balance right now. The German revolution has come from the grass roots: Individual citizens and energy genossenschaften—local citizens associations—have made half the investment in renewables. But conventional utilities, which didn’t see the revolution coming, are pressuring Merkel’s government to slow things down. The country still gets far more electricity from coal than from renewables. And the energiewende has an even longer way to go in the transportation and heating sectors, which together emit more carbon dioxide (CO₂) than power plants.

German politicians sometimes compare the energiewende to the Apollo moon landing. But that feat took less than a decade, and most Americans just watched it on TV. The energiewende will take much longer and will involve every single German—more than 1.5 million of them, nearly 2 percent of the population, are selling electricity to the grid right now. “It’s a project for a generation; it’s going to take till 2040 or 2050, and it’s hard,” said Gerd Rosenkranz, a former journalist at Der Spiegel who’s now an analyst at Agora Energiewende, a Berlin think tank. “It’s making electricity more expensive for individual consumers. And still, if you ask people in a poll, Do you want the energiewende? then 90 percent say yes.”

Why? I wondered as I traveled in Germany last spring. Why is the energy future happening here, in a country that was a bombed-out wasteland 70 years ago? And could it happen everywhere?

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View Images Workers have been taking apart this Soviet-era nuclear power plant, near Greifswald in eastern Germany, since 1995, cleaning radioactive surfaces with steel grit so the metal can be recycled. Germany plans to shut all its reactors by 2022.

The Germans have an origin myth: It says they came from the dark and impenetrable heart of the forest. It dates back to the Roman historian Tacitus, who wrote about the Teutonic hordes who massacred Roman legions, and it was embellished by German Romantics in the 19th century. Through the upheavals of the 20th century, according to ethnographer Albrecht Lehmann, the myth remained a stable source of German identity. The forest became the place where Germans go to restore their souls—a habit that predisposed them to care about the environment.

So in the late 1970s, when fossil fuel emissions were blamed for killing German forests with acid rain, the outrage was nationwide. The oil embargo of 1973 had already made Germans, who have very little oil and gas of their own, think about energy. The threat ofwaldsterben, or forest death, made them think harder.

Government and utilities were pushing nuclear power—but many Germans were pushing back. This was new for them. In the decades after World War II, with a ruined country to rebuild, there had been little appetite for questioning authority or the past. But by the 1970s, the rebuilding was complete, and a new generation was beginning to question the one that had started and lost the war. “There’s a certain rebelliousness that’s a result of the Second World War,” a 50-something man named Josef Pesch told me. “You don’t blindly accept authority.”

Pesch was sitting in a mountaintop restaurant in the Black Forest outside Freiburg. In a snowy clearing just uphill stood two 320-foot-tall wind turbines funded by 521 citizen investors recruited by Pesch—but we weren’t talking about the turbines yet. With an engineer named Dieter Seifried, we were talking about the nuclear reactor that never got built, near the village of Wyhl, 20 miles away on the Rhine River.

The state government had insisted that the reactor had to be built or the lights would go out in Freiburg. But beginning in 1975, local farmers and students occupied the site. In protests that lasted nearly a decade, they forced the government to abandon its plans. It was the first time a nuclear reactor had been stopped in Germany.

The lights didn’t go out, and Freiburg became a solar city. Its branch of the Fraunhofer Institute is a world leader in solar research. Its Solar Settlement, designed by local architect Rolf Disch, who’d been active in the Wyhl protests, includes 50 houses that all produce more energy than they consume. “Wyhl was the starting point,” Seifried said. In 1980 an institute that Seifried co-founded published a study called Energiewende—giving a name to a movement that hadn’t even been born yet.

View Images A nuclear reactor at Kalkar was finished just before the 1986 explosion at Chernobyl, Ukraine—and never used. It’s now an amusement park with a ride in what would have been the cooling tower. Fear of nuclear power spurred Germany’s transition.

It wasn’t born of a single fight. But opposition to nuclear power, at a time when few people were talking about climate change, was clearly a decisive factor. I had come to Germany thinking the Germans were foolish to abandon a carbon-free energy source that, until Fukushima, produced a quarter of their electricity. I came away thinking there would have been no energiewende at all without antinuclear sentiment—the fear of meltdown is a much more powerful and immediate motive than the fear of slowly rising temperatures and seas.

All over Germany I heard the same story. From Disch, sitting in his own cylindrical house, which rotates to follow the sun like a sunflower. From Rosenkranz in Berlin, who back in 1980 left physics graduate school for months to occupy the site of a proposed nuclear waste repository. From Luise Neumann-Cosel, who occupied the same site two decades later—and who is now leading a citizens’ initiative to buy the Berlin electric grid. And from Wendelin Einsiedler, a Bavarian dairy farmer who has helped transform his village into a green dynamo.

All of them said Germany had to get off nuclear power and fossil fuels at the same time. “You can’t drive out the devil with Beelzebub,” explained Hans-Josef Fell, a prominent Green Party politician. “Both have to go.” At the University of Applied Sciences in Berlin, energy researcher Volker Quaschning put it this way: “Nuclear power affects me personally. Climate change affects my kids. That’s the difference.”

Germany’s Audacious Goal Germany has Europe’s second highest consumer electricity prices, yet public support for its energiewende—an aggressive transition to renewable energy—is at an impressive 92 percent. The support is rooted in an eco-friendly culture, a collective desire to abandon nuclear energy, and laws that allow citizens to profit from selling their energy to the grid. Roughly 27 percent of Germany’s electricity is from renewables; the goal is at least 80 percent by 2050. Solar and Wind Energy in Germany Installed capacity by postal code area, megawatts per square mile OFFSHORE WIND FARM AREAS ALSO SHOWN Wind-dominant region 0.5 1.0 1.5 1.5+ Solar-dominant region 0.5 1.0 1.5 1.5+ Planned power line Operational nuclear reactor Closed nuclear reactor 2014 Green Day On July 25, 2015, it was very windy in the north and sunny in the south. For a few hours renewables yielded about three-quarters of Germany’s electricity. No Nukes After the disaster in Fukushima, Japan, in 2011, Germany vowed to quickly abandon nuclear energy. Of 17 operable reactors, nine have since been shuttered. The rest are set to close by 2022. **Reactor closed prior to 2011 2050 Offshore Promise Germany has invested heavily in energy generated by offshore wind and expects one-third of its future wind energy to come from offshore farms. Electricity Highways To bring renewable power from the windy north to the heavily industrialized south, government and utilities have proposed at least two high-voltage, direct current (HVDC) power lines. Landowners and even the Bavarian government are resisting the unsightly lines. A possible compromise: running some stretches of cable underground. Explosion of Renewables The government has boosted renewables by paying producers for energy and guaranteeing prices. Decline in Emissions Germany's renewable-energy surge has contributed to a 27 percent reduction in its greenhouse gas emissions. *Latest available data JASON TREAT, NG STAFF; EVAN APPLEGATE. SOURCES: FRAUNHOFER IWES, KASSEL; U.S. ENERGY INFORMATION ADMINISTRATION; GERMAN FEDERAL MINISTRY FOR THE ENVIRONMENT; EUROSTAT

If you ask why antinuclear sentiment has been so much more consequential in Germany than, say, across the Rhine in France, which still gets 75 percent of its electricity from nukes, you end up back at the war. It left Germany a divided country, the front along which two nuclear superpowers faced off. Demonstrators in the 1970s and ’80s were protesting not just nuclear reactors but plans to deploy American nuclear missiles in West Germany. The two didn’t seem separable. When the German Green Party was founded in 1980, pacifism and opposition to nuclear power were both central tenets.

In 1983 the first Green representatives made it into the Bundestag, the national parliament, and started injecting green ideas into the political mainstream. When the Soviet reactor at Chernobyl exploded in 1986, the left-leaning Social Democrats (SPD), one of Germany’s two major parties, was converted to the antinuclear cause. Even though Chernobyl was hundreds of miles away, its radioactive cloud passed over Germany, and parents were urged to keep their children inside. It’s still not always safe to eat mushrooms or wild boar from the Black Forest, Pesch said. Chernobyl was a watershed.

But it took Fukushima, 25 years later, to convince Merkel and her Christian Democratic Union (CDU) that all nuclear reactors should be switched off by 2022. By then the boom of renewable energy was in full swing. And a law that Hans-Josef Fell had helped create back in 2000 was the main reason.

Fell’s house in Hammelburg, the town in northern Bavaria where he was born and raised, is easy to spot among all the pale postwar stucco: It’s the one built of dark larch wood, with a grass roof. On the south side, facing the backyard, the grass is partially covered by photovoltaic and solar hot water panels. When there’s not enough sun to produce electricity or heat, a cogenerator in the basement burns sunflower or rapeseed oil to produce both. On the March morning when I visited, the wood interior of the house was bathed in sunlight and warmth from the conservatory. In a few weeks, Fell said, wildflowers would be blooming on the roof.

A tall man in jeans and Birkenstocks, with a bald, egg-shaped head and a fringe of gray beard, Fell has moments of sounding like a preacher—but he’s no green ascetic. A shed in his backyard, next to the swimming pond, houses a sauna, powered by the same green electricity that powers his house and his car. “The environmental movement’s biggest mistake has been to say, ‘Do less. Tighten your belts. Consume less,’ ” Fell said. “People associate that with a lower quality of life. ‘Do things differently, with cheap, renewable electricity’—that’s the message.”

See how German citizens are preparing for more renewable energy industries.

From Fell’s garden, on a clear day, you used to be able to see the white steam plumes of the nuclear reactor at Grafenrheinfeld. His father, the conservative mayor of Hammelburg, supported nuclear power and the local military base. Young Fell demonstrated at Grafenrheinfeld and went to court to refuse military service. Years later, after his father had retired, Fell was elected to the Hammelburg city council.

It was 1990, the year Germany was officially reunified—and while the country was preoccupied with that monumental task, a bill boosting the energiewende made its way through the Bundestag without much public notice. Just two pages long, it enshrined a crucial principle: Producers of renewable electricity had the right to feed into the grid, and utilities had to pay them a “feed-in tariff.” Wind turbines began to sprout in the windy north.

But Fell, who was installing PV panels on his roof in Hammelburg, realized that the new law would never lead to a countrywide boom: It paid people to produce energy, but not enough. In 1993 he got the city council to pass an ordinance obliging the municipal utility to guarantee any renewable energy producer a price that more than covered costs. Fell promptly organized an association of local investors to build a 15-kilowatt solar power plant—tiny by today’s standards, but the association was one of the first of its kind. Now there are hundreds in Germany.

In 1998 Fell rode a Green wave and his success in Hammelburg into the Bundestag. The Greens formed a governing coalition with the SPD. Fell teamed up with Hermann Scheer, a prominent SPD advocate of solar energy, to craft a law that in 2000 took the Hammelburg experiment nationwide and has since been imitated around the world. Its feed-in tariffs were guaranteed for 20 years, and they paid well.

“My basic principle,” Fell said, “was the payment had to be so high that investors could make a profit. We live in a market economy, after all. It’s logical.”

View Images Renewables are booming, but Germany’s use of lignite, the dirtiest coal, hasn’t declined. At Vattenfall’s Welzow-Süd mine, some of the world’s largest machines claw 22 million tons a year from a 45-foot-thick seam. How long will that go on? “Very long, I hope,” said Jan Domann, a young engineer. “We have enough lignite.”

Fell was about the only German I met who claimed not to have been surprised at the boom his logic unleashed. “That it would be possible to this extent—I didn’t believe that then,” said dairy farmer Wendelin Einsiedler. Outside his sunroom, which overlooks the Alps, nine wind turbines turned lazily on the ridge behind the cow pen. The smell of manure drifted in. Einsiedler had started his personal energiewende in the 1990s with a single turbine and a methane-producing manure fermenter. He and his brother Ignaz, also a dairy farmer, burned the methane in a 28-kilowatt cogenerator, generating heat and electricity for their farms. “There was no question of making money,” Einsiedler said. “It was idealism.”

But after the renewable energy law took effect in 2000, the Einsiedlers expanded. Today they have five fermenters, which process corn silage as well as manure from eight dairy farms, and they pipe the resulting biogas three miles to the village of Wildpoldsried. There it’s burned in cogenerators to heat all the public buildings, an industrial park, and 130 homes. “It’s a wonderful principle, and it saves an unbelievable amount of CO₂,” said Mayor Arno Zengerle.

The biogas, the solar panels that cover many roofs, and especially the wind turbines allow Wildpoldsried to produce nearly five times as much electricity as it consumes. Einsiedler manages the turbines, and he’s had little trouble recruiting investors. Thirty people invested in the first one; 94 jumped on the next. “These are their wind turbines,” Einsiedler said. Wind turbines are a dramatic and sometimes controversial addition to the German landscape—“asparagification,” opponents call it—but when people have a financial stake in the asparagus, Einsiedler said, their attitude changes.

It wasn’t hard to persuade farmers and homeowners to put solar panels on their roofs; the feed-in tariff, which paid them 50 cents a kilowatt-hour when it started in 2000, was a good deal. At the peak of the boom, in 2012, 7.6 gigawatts of PV panels were installed in Germany in a single year—the equivalent, when the sun is shining, of seven nuclear plants. A German solar-panel industry blossomed, until it was undercut by lower-cost manufacturers in China—which took the boom worldwide.

Fell’s law, then, helped drive down the cost of solar and wind, making them competitive in many regions with fossil fuels. One sign of that: Germany’s tariff for large new solar facilities has fallen from 50 euro cents a kilowatt-hour to less than 10. “We’ve created a completely new situation in 15 years—that’s the huge success of the renewable energy law,” Fell said.

Germans paid for this success not through taxes but through a renewable-energy surcharge on their electricity bills. This year the surcharge is 6.17 euro cents per kilowatt-hour, which for the average customer amounts to about 18 euros a month—a hardship for some, Rosenkranz told me, but not for the average German worker. The German economy as a whole devotes about as much of its gross national product to electricity as it did in 1991.

In the 2013 elections Fell lost his seat in the Bundestag, a victim of internal Green Party politics. He’s back in Hammelburg now, but he doesn’t have to look at the steam plumes from Grafenrheinfeld: Last June the reactor became the latest to be switched off. No one, not even the industry, thinks nuclear is coming back in Germany. Coal is another story.

Germany got 44 percent of its electricity from coal last year—18 percent from hard coal, which is mostly imported, and about 26 percent from lignite, or brown coal. The use of hard coal has declined substantially over the past two decades, but not the use of lignite. That’s a major reason Germany isn’t on track to meet its own greenhouse gas emissions target for 2020.

Germany is the world’s leading producer of lignite. It emits even more CO₂ than hard coal, but it’s the cheapest fossil fuel—cheaper than hard coal, which is cheaper than natural gas. Ideally, to reduce emissions, Germany should replace lignite with gas. But as renewables have flooded the grid, something else has happened: On the wholesale market where contracts to deliver electricity are bought and sold, the price of electricity has plummeted, such that gas-fired power plants and sometimes even plants burning hard coal are priced out of the market. Old lignite-fired power plants are rattling along at full steam, 24/7, while modern gas-fired plants with half the emissions are standing idle.

View Images The chalk cliffs at Jasmund National Park on the Baltic have drawn tourists for centuries. The beech woods there are a remnant of the forest that once covered Germany. According to Romantic lore, the forest forged the German identity as a nature-loving people—a key inspiration for the clean-energy movement. When a quarry threatened this site in the 1920s, ranger Rico Markmann explains, “the populace didn’t stand for it.”

“Of course we have to find a track to get rid of our coal—it’s very obvious,” said Jochen Flasbarth, state secretary in the environment ministry. “But it’s quite difficult. We are not a very resource-rich country, and the one resource we have is lignite.”

Curtailing its use is made harder by the fact that Germany’s big utilities have been losing money lately—because of the energiewende, they say; because of their failure to adapt to the energiewende, say their critics. E.ON, the largest utility, which owns Grafenrheinfeld and many other plants, declared a loss of more than three billion euros last year.

“The utilities in Germany had one strategy,” Flasbarth said, “and that was to defend their track—nuclear plus fossil. They didn’t have a strategy B.” Having missed the energiewende train as it left the station, they’re now chasing it. E.ON is splitting into two companies, one devoted to coal, gas, and nuclear, the other to renewables. The CEO, once a critic of the energiewende, is going with the renewables.

Vattenfall, a Swedish state-owned company that’s another one of Germany’s four big utilities, is attempting a similar evolution. “We’re a role model for the energiewende,” spokesperson Lutz Wiese said cheerfully as he greeted me at Welzow-Süd—an open-pit mine on the Polish border that produces 22 million tons of lignite a year. In a trench that covers 11 square miles and is more than 300 feet deep, 13 gargantuan digging machines work in synchrony—moving the trench through the landscape, exposing and removing the lignite seam, and dumping the overburden behind them so the land can be replanted. In one recultivated area there’s a small experimental vineyard. On the same rebuilt hill stands a memorial to Wolkenberg, a village consumed by the mine in the 1990s. Boulders mark the spots where the church and other buildings once stood.

It was a gorgeous spring day; from Wolkenberg, the only cloud we could see was the lazily billowing steam plume from the 1.6-gigawatt power plant at Schwarze Pumpe, which burns most of the lignite mined at Welzow-Süd. In a conference room, Olaf Adermann, asset manager for Vattenfall’s lignite operations, explained that Vattenfall and other utilities had never expected renewables to take off so fast. Even with the looming shutdown of more nuclear reactors, Germany has too much generating capacity.

View Images Citizens have funded half of Germany’s investment in renewable energy after a law made it profitable. Outside the village of Feldheim, visitors tour the wind park. It sells electricity to the national grid—but also supplies a local grid that makes Feldheim self-sufficient.

“We have to face some kind of a market cleaning,” Adermann said. But lignite shouldn’t be the one to go, he insisted: It’s the “reliable and flexible partner” when the sun isn’t shining or the wind isn’t blowing. Adermann, who’s from the region and worked for its lignite mines before they belonged to Vattenfall, sees them continuing to 2050—and maybe beyond.

Vattenfall, however, plans to sell its lignite business, if it can find a buyer, so it can focus on renewables. It’s investing billions of euros in two new offshore wind parks in the North Sea—because there’s more wind offshore than on and because a large corporation needs a large project to pay its overhead. “We can’t do onshore in Germany,” Wiese said. “It’s too small.”

Vattenfall isn’t alone: The renewables boom has moved into the North and Baltic Seas and, increasingly, into the hands of the utilities. Merkel’s government has encouraged the shift, capping construction of solar and onshore wind and changing the rules in ways that shut out citizens associations. Last year the amount of new solar fell to around 1.9 gigawatts, a quarter of the 2012 peak. Critics say the government is helping big utilities at the expense of the citizens’ movement that launched the energiewende.

At the end of April, Vattenfall formally inaugurated its first German North Sea wind park, an 80-turbine project called DanTysk that lies some 50 miles offshore. The ceremony in a Hamburg ballroom was a happy occasion for the city of Munich too. Its municipal utility, Stadtwerke München, owns 49 percent of the project. As a result Munich now produces enough renewable electricity to supply its households, subway, and tram lines. By 2025 it plans to meet all of its demand with renewables.

In part because it has retained a lot of heavy industry, Germany has some of the highest per capita carbon emissions in western Europe. (They’re a bit more than half of U.S. emissions.) Its goal for 2020 is to cut them by 40 percent from 1990 levels. As of last year, it had achieved 27 percent. The European carbon-trading system, in which governments issue tradable emissions permits to polluters, hasn’t been much help so far. There are too many permits in circulation, and they’re so cheap that industry has little incentive to cut emissions.

Though Germany isn’t on track to meet its own goal for 2020, it’s ahead of the European Union’s schedule. It could have left things there—and many in Merkel’s CDU wanted her to do just that. Instead, she and Economics Minister Sigmar Gabriel, head of the SPD, reaffirmed their 40 percent commitment last fall.

View Images In 1996 the Kalkar nuclear reactor site, on the Rhine near Holland, opened as an amusement park: Wunderland Kalkar. By 2050 Germany aims to be a new kind of wonderland—an industrial country that uses half as much energy as before and gets at least 80 percent from renewables.

They haven’t proved they can meet it, however. Last spring Gabriel proposed a special emissions levy on old, inefficient coal plants; he soon had 15,000 miners and power plant workers, encouraged by their employers, demonstrating outside his ministry. In July the government backed down. Instead of taxing the utilities, it said it would pay them to shut down a few coal plants—achieving only half the planned emissions savings. For the energiewende to succeed, Germany will have to do much more.

It will have to get off gasoline and diesel too. The transportation sector produces about 17 percent of Germany’s emissions. Like the utilities, its famous carmakers—Mercedes-Benz, BMW, Volkswagen, and Audi—were late to the energiewende. But today they’re offering more than two dozen models of electric cars. The government’s goal is to have a million electric cars on the road by 2020; so far there are about 40,000. The basic problem is that the cars are still too expensive for most Germans, and the government hasn’t offered serious incentives to buy them—it hasn’t done for transportation what Fell’s law did for electricity.

Much the same is true of buildings, whose heating systems emit 30 percent of Germany’s greenhouse gases. Rolf Disch in Freiburg is one of many architects who have built houses and buildings that consume almost no net energy or produce a surplus. But Germany is not putting up many new buildings. “The strategy has always been to modernize old buildings in such a way that they use almost no energy and cover what they do use with renewables,” said Matthias Sandrock, a researcher at the Hamburg Institute. “That’s the strategy, but it’s not working. A lot is being done, but not enough.”

All over Germany, old buildings are being wrapped in six inches of foam insulation and refitted with modern windows. Low-interest loans from the bank that helped rebuild the war-torn west with Marshall Plan funds pay for many projects. Just one percent of the stock is being renovated every year, though. For all buildings to be nearly climate neutral by 2050—the official goal—the rate would need to double at least. Once, Sandrock said, the government floated the idea of requiring homeowners to renovate. The public outcry shot that trial balloon down.

“After Fukushima, for a short time there was aufbruchstimmung—for about half a year there was a real euphoria,” said Gerd Rosenkranz. Aufbruchstimmung means something like “the joy of departure”; it’s what a German feels when he’s setting out on a long hike, say, in the company of friends. With all the parties in Germany in agreement, Rosenkranz said, the energiewende felt like that. But the feeling hasn’t lasted. Economic interests are clashing now. Some Germans say it might take another catastrophe like Fukushima to catalyze a fresh burst of progress. “The mood is bad,” Rosenkranz said.

But here’s the thing about the Germans: They knew the energiewende was never going to be a walk in the forest, and yet they set out on it. What can we learn from them? We can’t transplant their desire to reject nuclear power. We can’t appropriate their experience of two great nation-changing projects—rebuilding their country when it seemed impossible, 70 years ago, and reunifying their country when it seemed forever divided, 25 years ago. But we can be inspired to think that the energiewende might be possible for other countries too.