06 Sep 2022, 13:50
Benjamin Wehrmann

Econ min proposes to keep two of Germany’s remaining nuclear plants on standby during winter

Nuclear power plant Isar in southern Germany. Photo: Preussen Elektra.
Nuclear power plant Isar in southern Germany. Photo: Preussen Elektra.

Germany should keep two of its three remaining nuclear power plants on standby beyond the planned phase-out date at the end of the year to help secure power system stability in the coming winter if necessary, economy and climate minister Robert Habeck has said. A long-awaited grid stress test had found that the two plants located in southern Germany could be of help in certain “very unlikely” emergency situations, meaning the plants should move into a reserve until April next year before they are permanently decommissioned, the minister said. The plants would only be reactivated to produce electricity if other instruments are not sufficient to avert a supply crisis in Germany's industrial south. Chancellor Olaf Scholz’s SPD welcomed the Green Party minister’s proposal, while their coalition partner FDP vowed to advocate a runtime extension also for the third plant when the extension is decided in parliament. Environmental groups in the country wholly rejected a runtime extension, arguing this would cancel a longstanding phase-out consensus and obstruct the urgent need to build more renewables.

Two of Germany’s three remaining nuclear plants should not go fully offline as planned at the end of this year but instead will remain in an emergency reserve until mid-April 2023 to provide a backup for the power grid if needed, economy and climate minister Robert Habeck said in Berlin. The Green Party minister presented the results of a grid “stress test” conducted over several weeks by Germany’s transmission grid operators, which found that keeping the two nuclear plants in the south of the country operational could help avoid grid bottlenecks in extreme situations during the upcoming winter. The plants, Isar 2 in Bavaria and Neckarwestheim 2 in Baden-Wurttemberg, will be on standby for several months after the scheduled end date on 31 December to possibly “contribute in certain stress situations in the power grid”. The Emsland plant, in northern Germany, will be decommissioned as planned. The proposal by Habeck's ministry must now be debated by the government and by parliament, as legislative reforms are necessary.

The decision means that Germany will stick to the nuclear phase-out as regulated by law, said Habeck. New fuel elements would not be loaded, and the new reserve would be ended by mid-April 2023. "Nuclear power is and will remain a high-risk technology and the highly radioactive waste will burden many generations to come," said Habeck.

The stress test’s results had been awaited for weeks, as Europe’s energy crisis pushed gas and electricity prices to unprecedented levels and led to fears over household budgets and businesses collapsing due to unaffordable energy bills as well as possible gas rationing that could lead to lasting economic damage in entire industries. While Habeck’s Green Party and chancellor Olaf Scholz’s Social Democrats (SPD) have insisted that delaying the nuclear power phase-out in a so-called “stretched operation” mode would only be an option for several months into the next year, finance minister Christian Lindner, of their coalition partner Free Democrats (FDP), had joined the conservative CDU/CSU opposition alliance in calling for a longer extension for several years. This would include procuring new nuclear fuel rods and changing the country’s carefully balanced nuclear exit law. The FDP and opposition parties point to a shift in attitude among German citizens, whose rejection of nuclear power has dropped in the wake of the energy crisis, but the SPD and the Greens have ruled out any longer extension.

Due to the technology's risks, “a sweeping runtime extension is not justifiable, also with regard to the plant’s security standards,” Habeck argued. Any changes to Germany’s existing nuclear exit law would therefore only entail a limited runtime extension until spring next year. The minister said he does not expect plants to be turned off and on several times. If Germany decided to keep the plants online during the coming winter -- a decision which could already be taken in December -- then the plants would run continuously until April. Following intensive monitoring of the power supply situation, the economy ministry would propose to give the plants a limited runtime extension. The grid agency would then recommend to get them out of the reserve. The final decision is then to be made via government decree with the possibility of objection by the parliament.

In an interview with public broadcaster ARD following his announcement, Habeck vehemently rejected concerns the decision to limit the runtime extension could jeopardize supply security. “Germany’s energy supply is safe, we have enough energy and our grid is secure,” he said.

Germany cannot be certain to receive enough energy from abroad in “very unlikely” emergency

Following a first assessment earlier this year, the second stress test took into account the drought across Europe this summer, low water levels in rivers, the outage of about half of the France’s nuclear power plant fleet, and the overall tense situation on the energy markets since the start of Russia’s war. It also paid particular attention to the interaction of the national power grid with those of neighbouring states, as Germany's central geographic location connects it with 11 other European countries.

Habeck stressed that renewable power expansion, especially in southern Germany, had not progressed at the necessary speed in the past years, making a higher use of coal plants and possibly also the limited runtime extension for the nuclear reactors necessary in the current crisis. Given the Europe-wide supply challenges, Germany could not be certain of receiving enough energy from abroad in case of a shortfall. He stressed that “it continues to be very unlikely that we run into a crisis situation and extreme scenarios”, but precautions had to be taken.

Conducted jointly by grid operators 50Hertz, Tennet, Amprion and TransnetBW, the assessment found that “crisis-like situations in the power system for some hours are very unlikely in the winter of 2022/2023 but cannot be ruled out entirely at the moment”. 50Hertz head Stefan Kapferer said the test had shown that Europe as a whole is facing a “tense” situation for its power systems. “Our message therefore is clear: it makes sense and is necessary to use all options for increasing our power production and transmission capacities,” Kapferer said. Letting the two plants run a few months longer could be only one measure out of many to alleviate supply security risks. Kapferer said the grid operators had recommended to keep all three plants in the emergency reserve but stressed that the “political decision” to take the Emsland plant offline as planned would be acceptable from a technical point of view, as the plant in northern Germany cannot contribute as much to grid stability as the two southern ones.

However, the stress test also found that the plants could only make a limited contribution to stabilising the system in critical situations. In a “very critical” scenario studied in the test, the reactors would reduce the demand for power imports by merely 0.5 gigawatts (GW), meaning total demand for power from abroad would remain at 4.6 GW in these circumstances. The transmission grid operators, therefore, also called for measures like increasing the transport capacity for electricity from northern to southern Germany. Moreover, Germany should make provisions to secure capacity from power plants abroad to balance grid bottlenecks, while large power consumers in the industry should be given financial incentives to forego part of their power consumption in case of supply shortages.

Coalition partner FDP vows to advocate for keeping third plant in operation

The decision by the Green-led ministry was welcomed by the leader of the SPD’s parliamentary group, Matthias Miersch. He said the stress test had provided “a sound foundation for a fact-based and thorough debate in parliament”, which would have to precede any final decision on extending the two plants’ runtime. Miersch said the test had demonstrated that nuclear power “is not the general solution many had hoped for it to be”. With a view to the neglect of wind power expansion by Bavaria’s CSU government, he argued grid instability would be a risk “especially in regions where wind power and power grids have not been expanded for years”. All efforts should now be directed at building out renewable energy generation, Miersch argued.

Representatives of the pro-business FDP were not satisfied with the stress test’s outcome. “Habeck’s emergency reserve is a step ahead, but it also appears to be a political emergency exit,” FDP parliamentary group leader Johannes Vogel said. Enabling generation of every kilowatt hour of climate neutral power would be “a matter of reason” in the current situation, which is why his party would continue to advocate for keeping all three plants on the grid, Vogel said.

The leader of the opposition Christian Democrats (CDU), Friedrich Merz, criticised the economy and climate ministry’s decision before it had been officially announced, arguing that “it makes no sense to talk about reserves, stand-by operation or anything similar to that”. Instead, Germany should “run all three nuclear power plants at full steam”, Merz said. New fuel rods should be bought quickly to enable operation “for possibly another three to four years, until we’ve left this crisis behind”.

Economist Sonja Peterson, from research institute IfW Kiel, said Habeck had given the government “political leeway” with the call for a limited runtime extension of the two plants. However, the effect would be greater at the European level than its safety benefits for Germany’s national energy system. Nuclear power plants could cover less than five percent of the country’s gas demand and, unlike gas-fired plants, are unable to respond quickly to demand peaks. “But in the currently very volatile situation, all options for saving gas are useful, expand the range of possible policies and dampen the power price rise,” Peterson said. As Germany had brought its current predicament upon itself by increasing its energy dependence on Russia over many years, allowing a runtime extension would be a necessary concession to European partners for ensuring solidarity in gas supply, she argued. However, the current crisis had “not changed anything” regarding the medium- to long-term usefulness of nuclear power, meaning it remained “an expensive, risk-laden and conflict-prone technology that does not fit into a power system based on renewable energy”, Peterson said.

Environmental groups warn against “cancelling societal consensus” for phase-out

Greenpeace criticised Habeck’s decision for “cancelling a hard-won societal consensus” on ending nuclear power. Keeping the reactors running longer than planned would be “unacceptable” and delay the energy transition in southern Germany. Irrespective of the supply crisis, the “last and old” nuclear plants could be no solution, NGO head Martin Kaiser commented. He called on the parliament to reject Habeck’s proposal. Expanding renewables “at the speed of light” and reducing power consumption would be better options to get through the crisis, Kaiser argued.

The consensus on ending nuclear power this year should not be reversed “even as a reserve,” Jörg-Andreas Krüger, head of environmental NGO Nabu commented. The maintenance problems in the French nuclear fleet and also the current risk of a nuclear disaster at the embattled Zaporizhzhia nuclear power station in Ukraine would be stark reminders of the dangers lurking in the technology. “And we’ve not even started talking about the unresolved question of nuclear waste,” Krüger added. The fact that many nuclear plants in Europe had to be taken offline during the summer because not enough cooling water was available also demonstrated that the reactors are not a completely reliable option for power supply. He too said a fast expansion of renewables would be the only lasting way out of the energy crisis.

Lutz Weischer, of NGO Germanwatch, said it would be “absurd if the answer to the safety issues at old French reactors would be to run old German reactors longer”. The stress test had confirmed that a lifetime extension has a very limited effect on grid stability. “What Habeck has proposed with the safety reserve for four months is a safety measure that will most likely never be used,” he said.

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