The Chancellor has decided. The last three nuclear power plants will remain online longer – until April 15. But the debate about the role of nuclear power in the current energy crisis continues. Opponents of nuclear power doubt that the three power plants – especially the one in Emsland in Lower Saxony – will make any significant contribution to security of supply in Germany. Advocates of renewable energies even criticize that the reactor in northern Germany is blocking the power grid for wind power and is thus making the energy transition more difficult. Proponents of lifetime extensions, on the other hand, argue that the nuclear power plants (NPP) increased production, ensured grid stability and lowered prices. Demands for an extension beyond spring 2023 are already being made. What is the truth behind the arguments for and against the continued operation of the last three German nuclear power plants?

Do we have a problem with grid stability in Germany? And what can the three nuclear power plants do to change that?

In order to keep the power grid stable and avoid blackouts, power consumption and feed-in must always be precisely balanced. In Germany, however, we have – long before the current crisis – the problem that in the north, with high wind availability, a lot of electricity is produced and there is comparatively little demand, while in the south, high demand tends to be offset by less production. “Especially in winter, when there is a lot of wind in the north and demand increases in the south, the line capacity between northern and southern Germany is not sufficient to compensate for this difference,” explains Mirko Schlossarczyk, partner at the energy consulting company Enervis. In the north, this could mean that wind turbines have to be shut down. “In the worst case, however, there could be supply bottlenecks in the south,” says Schlossarczyk. “The continued operation of the Neckarwestheim and Isar II nuclear power plants, which are located right in the critical grid area, helps to avoid such bottlenecks.” According to Tobias Federico, managing director of the consulting firm Energy Brainpool, one important aspect has been neglected as a result of the discussion about nuclear power plants: “We would have been better off concentrating on savings in consumption.”

What about the nuclear power plant in Emsland?

The power plant in Lingen is located in the Emsland in northern Germany, where there is more than too little electricity in winter. Experts disagree on whether it makes sense to keep the reactor running this winter. “The Emsland nuclear power plant doesn’t help at all for grid stability,” says Federico. Schlossarcyk, on the other hand, thinks scenarios are conceivable “in which this power plant also provides relief on the electricity market, for example when there is little wind or the situation in the French power plant park does not improve significantly”. It is “clearly about risk minimization in view of possible supply bottlenecks”.

Is the Emsland nuclear power plant “clogging up” the power grid for climate-friendly wind power?

In order to keep the power grid stable, countermeasures must be taken in the event of “non-ideal grid flows”, explains Federico. In northern Germany, this means that wind turbines are switched off if they produce more electricity than is needed or can be transported further through the grid. Here, too, the central problem is the lack of transport capacity to southern Germany. “If the Emsland nuclear power plant then also produces electricity, that doesn’t help,” states Federico. Schlossarcyk sees it a little differently: higher electricity production in certain grid regions increases the probability that wind turbines will have to be shut down in some situations when there is high wind availability. “However, in the current crisis, the aspect of climate protection is somewhat behind the aspect of risk minimization and network security,” says the expert.

Does the continued operation of the nuclear power plants help to save significant gas in electricity production?

Model calculations by the experts come to similar conclusions. The nuclear power plants could help save around 6 terawatt hours of gas by April 15th. That is less than two percent of the total German consumption. Not enough to have a significant impact on gas prices, for example.

Will the additional nuclear power affect the price of electricity?

“The nuclear power plants are likely to drive at least the particularly inefficient and therefore expensive gas-fired power plants out of the market,” says Schlossarcyk. Overall, Enervis predicts a moderate reduction in the wholesale price of around six euros or 2.5 percent on average in 2023 compared to a scenario without an extension of the term. This roughly corresponds to Brainpool’s calculations of an effect of around one cent gross per kilowatt hour for consumers. “That’s nice given the current price of around 40 cents, but it doesn’t move the needle,” summarizes Federico.

Do the operators even have enough fuel elements?

Yes, close. “The plant can be operated with the available fuel until April 15, but with increasingly reduced performance,” says RWE about its reactor in Emsland. According to EON, Isar 2 can run until March 2023 with the existing fuel elements. According to ENBW, the following applies to Neckarwestheim: Electricity production up to April 15, 2023 is basically feasible with the existing fuel elements. “However, electricity production beyond the second quarter of 2023 is impossible with the existing fuel elements.”

What about the necessary specialist staff in the power plants that have been scheduled to be shut down for years?

The necessary staffing is secured, explains EON. Some employees had agreed not to take early retirement, but to remain available for continued operations. According to its own statements, ENBW can also rely on its experienced staff. This is available because the employees were shown long-term career prospects and given an employment guarantee more than ten years ago after the decision to phase out nuclear power. The same employees would also be needed for the demolition of the nuclear power plants because their nuclear know-how is also very valuable for dismantling.

Isn’t the real problem in France, where a large number of nuclear power plants are not connected to the grid due to various problems?

According to Federico, this is not the reason to continue operating the nuclear power plants. The German nuclear power plants could help France a bit. “But when it’s cold, we export around 14 gigawatts of power. The Emsland nuclear power plant, for example, has an output of 1,400 megawatts, so the share of the nuclear power plants is not large.” Schlossarczyk explains: “France is a major factor on the European electricity market and in the current crisis – but not the only one.” In winter, France is regularly dependent on electricity imports, and grid shutdowns are not uncommon there. “This is critical at the moment because there are problems in Germany, where base load power plants are not sufficiently connected to the grid and gas is currently extremely expensive,” says Schlossarczyk.

Do we have to fear that next winter will be even more difficult?

In terms of energy shortages, Federico does not expect major problems in the winter of 2023/24. Until then, Germany will be able to import enough liquid gas. “But the danger of sabotaging critical infrastructure is growing,” warns the Energy Brainpool boss – “all the more so the better we get through the winter.” Enervis expert Schlossarczyk, on the other hand, does not yet see the gas supply secured for next winter. “If you assume that we will not receive any gas from Russia in the foreseeable future, it could be challenging to reach the necessary storage levels before winter 23/24,” he warns. At least worst-case scenarios are conceivable in which the power supply in Germany is not completely secured in the coming winter, precisely because the wind availability is low or the situation in France is repeating itself.

Schlossarczyk therefore considers it “not unrealistic” that there will be a discussion about the continued operation of the nuclear power plants after April 15th. “However, this is much more complicated than the stretching operation that has now been decided for a few months.” The operators would have to order appropriate new fuel elements at an early stage. Once these fuel rods have been put into operation, they cannot simply be switched off. “Then they have to remain in the reactor cores for about four years and produce electricity,” explains Schlossarcyk. “Moreover, an amendment to the Atomic Energy Act would also be necessary, which not only the Greens, but also the SPD have so far categorically rejected.”