FÖS calculated the support, which includes both state support, power prices and external costs, had been the most draining of all energy sources on the finances of the country, which is Europe’s largest economy.

“No other energy source has caused costs as high as those of risky atomic power, which even after 65 years continues highly uneconomical,” said Sönke Tangermann, chairman of independent power provider Greenpeace Energy, which had commissioned the study.

Germany by the end of 2022 is phasing out nuclear power. Since a first reactor started operations in 1955, the country had built more than 100 nuclear facilities, including power and research stations, and waste deposits.

Other countries, such as Switzerland, have followed Germany’s lead and will also phase out nuclear power, while France at least wants to diminish the share of atomic power in its energy mix.

But at the same time a new debate has started to build supposedly cheap mini nuclear reactors for power or hydrogen production. While none of these have been built yet, prices for the construction of conventional new nuclear plants in countries like France or Finland have ballooned into amounts several times the original cost estimate.

Direct and indirect German government subsidies alone, including research grants and tax credits, since the mid-1950s have added up to €287bn, FÖS has calculated. Another €9bn were spent on other costs for the state, such as police operations during anti-nuclear protests, or follow-up costs from nuclear operations in former Eastern Germany.

“Great part of these costs never had been included in the electricity price, which is why atomic energy wrongly was considered as a cheap power source,” Tangermann said, adding that the study for the overall costs of nuclear energy has included external costs that had been passed on to society for decades, such as the risk of accidents.

Even after Germany’s nuclear exit, the country will face high costs, such as at least €7bn for the rehabilitation of the Morsleben nuclear storage facility and the Asse research storage facility as well as the Wismut uranium ore mine, or for the closure of former nuclear power plant sites.

Tangermann said he hopes Berlin will resist current demands for an extension of Germany’s nuclear power plants, or investments into new ones, also as those would serve to discredit the expansion of renewables.

“Given the enormous costs and aging infrastructure with ever greater risks, nuclear power cannot be a serious alternative to effectively tackling the climate crisis,” he said.