Germany shut its last three nuclear reactors on April 15, 2023. That year, the country’s power-sector emissions fell 21 percent to a record low of 177 million tons. Coal absorbed nuclear’s lost output for most of the decade before that, but renewables have since pulled ahead of it and coal’s share keeps shrinking.
If you’re trying to figure out whether a nuclear phase-out helps or hurts a climate plan, Germany already ran the experiment. Coal came back before renewables did, and emissions fell anyway once they caught up.
What filled the hole nuclear left behind
Nuclear supplied more than a quarter of German electricity as recently as 2010, when the country’s 17 reactors generated 133 terawatt-hours. After 8 of those 17 reactors went offline in 2011, cutting nuclear output roughly in half, the lost generation didn’t shift to wind turbines. Reporting on the years since Fukushima shows reductions in nuclear generation were offset primarily by increases in coal, not by the renewable buildout that was supposed to be the long-term answer (CNN).
Renewables kept growing through the 2010s, but not fast enough to close the gap outright. By the time the last three reactors closed in April 2023, nuclear was still supplying about 6 percent of German electricity, and coal had climbed to more than 30 percent.
When a reactor goes offline, the grid needs something to answer the gap that same hour. A coal plant already sits on standby, its stacks built and permitted, while a solar field a few miles away still needs two or three years of construction before it can connect to the grid. Wind and solar add capacity gradually. Without enough storage or transmission to move their output where it’s needed, they can’t step in for a retired reactor on short notice.
The 2022 energy crisis pushed the same lever harder. If you heated a German home that winter, you felt it directly. Gas covers almost half of German home heating, and Russia had supplied 55 percent of the country’s gas imports in 2021.
When Russian gas deliveries collapsed after the invasion of Ukraine, Berlin passed the Substitute Power Plants Maintenance Act to bring mothballed coal capacity back into the grid. It moved roughly 2.7 gigawatts of lignite units and several gigawatts of hard coal plants out of cold reserve between mid-2022 and early 2023, to save gas for winter heating. Delaying the nuclear exit and reviving coal plants were two sides of the same emergency response.
Climate scientists don’t agree on whether losing that last 6 percent of nuclear was worth it, or how safe those reactors were to begin with. Hans von Storch, a climate researcher at Germany’s Institute for Coastal Research, called the decision “incomprehensible” from a climate standpoint. Niklas Höhne, who studies climate policy at Wageningen University, took the opposite position. Phasing out nuclear, he argued, gave renewables the certainty to scale “much faster, cheaper and safer” than nuclear power could.
What economists found it cost
An economics team, Stephen Jarvis, Olivier Deschenes and Akshaya Jha, tried to put a number on that substitution. Their study traced what happened after Germany shut down more than half its nuclear capacity in the wake of Fukushima. It circulated first as an NBER working paper in 2019 and was published in 2022 in the Journal of the European Economic Association.
Their finding matches the pattern above. The lost nuclear output was replaced primarily by coal-fired production and net electricity imports.
The published version puts the added social cost of that substitution at €3 billion to €8 billion a year, mostly from the mortality risk that local air pollution from burning coal creates. If you live near one of the plants that picked up nuclear’s old load, that mortality risk is the bill you paid instead of a bigger charge on a power statement. Most of the total has nothing to do with carbon.
An earlier working-paper version of the same research had put the annual toll at about $12 billion, with more than 70 percent of it coming from that same air-pollution mortality channel. The estimates moved between drafts. The conclusion didn’t. The accident and waste-disposal risks that motivated the phase-out were real, and by the authors’ own accounting, still smaller than the health and climate costs of running coal harder in nuclear’s place.
Where German power emissions stand now
The renewable buildout that was meant to replace nuclear has largely caught up, years after the fact. Renewables supplied more than half of Germany’s gross electricity consumption for the first time in 2023, the same year power-sector CO2 emissions fell 21 percent to 177 million tons. In 2024, renewables reached 55 percent of consumption, and coal-fired generation dropped another 16 percent year on year.
Germany’s federal environment agency put the energy sector’s 2024 emissions decline at more than 15 million tons, a 7.4 percent year-on-year drop, driven mainly by lower coal and lignite burning. The carbon intensity of German grid power fell alongside it, from 433 grams of CO2 per kilowatt-hour in 2022 to 386 grams in 2023 and 363 grams in 2024. That’s a cleaner electron for anything you plug in, a dishwasher or an EV charger, than the German grid delivered two years earlier.
What 2025 looked like without nuclear at all
The full 2025 numbers show the same trend continuing, with no nuclear anywhere in the mix. Wind became Germany’s largest electricity source for the year at 132 terawatt-hours, and solar generation rose 21 percent to overtake lignite for the first time on record. That’s what solar can do without nuclear left to lean on, and it’s real context if you’re weighing panels for your own roof. Renewables held at 55.9 percent of net public electricity generation, per Fraunhofer ISE.
Coal hasn’t gone away. It still covers the gaps on windless, sunless days, the moment you’d notice it most if you lived on that grid, and it came back briefly during the 2022 gas crisis. Every year since the phase-out finished, though, coal has lost ground to renewables and imports.
How the phase-out happened
Germany’s exit from nuclear power didn’t start with Fukushima. It started nine years earlier, when Chancellor Gerhard Schröder’s SPD-Green government struck what’s known in Germany as the nuclear consensus, a 2000 deal with the country’s utilities to cap reactor lifespans at roughly 32 years and wind the fleet down by around 2022, written into law in 2002 as an amendment to the Atomic Energy Act.
The center-right government elected in 2009 tried to undo it. Angela Merkel’s coalition with the FDP extended reactor operating licenses by eight to fourteen years in 2010, which drew large protests. Roughly 40,000 people marched in Berlin that autumn.
Then came Fukushima. Merkel imposed a three-month moratorium within days of the disaster and took 8 of the country’s 17 operating reactors offline for review. By June, she had reversed course for good, keeping those reactors shut permanently and setting the remaining nine to close by 2022 with support from more than 80 percent of Bundestag members.
The last three plants, Emsland, Isar 2 and Neckarwestheim, were due to close at the end of 2022. Russia’s invasion of Ukraine and the resulting gas squeeze pushed Berlin to delay that by three and a half months. Parliament approved a one-time extension to April 15, 2023, with no further extensions on offer. That’s the date nuclear power in Germany ended, and the last day it showed up on a German electricity bill in any form.
| Date | What happened |
|---|---|
| 2000-2002 | Schröder government and utilities agree the “nuclear consensus,” written into law as an Atomic Energy Act amendment |
| 2010 | Merkel government extends reactor lifespans by 8-14 years |
| March 2011 | Fukushima triggers a moratorium, and 8 of Germany’s 17 reactors go offline |
| June 2011 | Bundestag votes to close the remaining nine reactors by 2022 |
| Late 2022 | Gas crisis prompts a short extension for the last three plants |
| April 15, 2023 | Emsland, Isar 2 and Neckarwestheim close, taking German nuclear output to zero |
Source: Clean Energy Wire, U.S. Energy Information Administration (EIA)
Fusion and small reactors are the only nuclear left on the table
Katherina Reiche, Germany’s energy minister, said in May 2025 that the phase-out is complete, and that restarting conventional reactors would need investor money and trust the country doesn’t have right now. “I don’t see companies investing on their own initiative,” she said. The coalition agreement she serves under still funds a first nuclear fusion reactor in Germany, and Reiche called small modular reactors “another matter” worth a separate look.
Everything else in her ministry’s actual plan, wind, solar, storage and transmission, is the technology already running the German grid without a single reactor. Conventional nuclear in Germany is closed for good. The fusion reactor and the small modular reactors Reiche mentioned are still lines in a coalition agreement. Neither one has produced a kilowatt-hour yet.
