The nuclear phase-out – myths about stretchout operation and extension of lifetimes

The nuclear phase-out is a done deal. However, in response to the gas crisis, it is once again being discussed. In this two-part blog article, we explain why Germany should abide by its commitment to phase out nuclear power. Part One: The energy industry.

Part One: The energy industry

Germany’s three remaining nuclear power plants are due to be shut down at the end of 2022, as stipulated in the German Atomic Energy Act (Atomgesetz – AtG). The expiry of the operating licences for the Emsland, Neckarwestheim 2 and Isar 2 plants will mark the end of the nuclear age in Germany. However, the war in Ukraine and the gas crisis have now sparked a discussion about the option of standby or stretchout operation for the German nuclear power plants and a possible extension of their lifetimes. But the answers given by supporters of these options to urgent energy security issues ignore energy policy reality and jeopardise the social consensus, reached in 2011, on a safe and sustainable energy supply. Instead, myths about security of supply and electricity prices abound. In this blog article, we examine these myths from a scientific perspective.

1. The nuclear power plants can only replace gas-fired power plants to a very limited extent.

The myth: We need nuclear power to cope with the gas crisis this winter.

Germany’s annual consumption of natural gas amounts to around 998 terawatt hours (TWh). Most of it is used in heat production for buildings or in industrial processes and cannot be replaced by nuclear power. Nuclear power plants would, at best, serve as a substitute in power generation, but not in heat production. The German Association of Energy and Water Industries (BDEW) has estimated the nuclear power plants’ potential to replace gas-fired power plants in electricity generation at around 3 TWh, equivalent to 0.6% of total consumption in 2020/2021. The results of the second stress test even indicate that continuing to operate the three nuclear power plants would save only one thousandth of Germany’s gas consumption.

The truth: Operating the three nuclear power plants in stretchout mode will therefore contribute very little to energy supply security or to any effective response to a potential gas crisis this winter.

Also true: The gas-fired power plants which only produce electricity perform a specific function in the energy market, not least for the grids. They are highly flexible and can start operating very quickly to compensate for any shortfall in energy generation from wind or solar. Nuclear power plants are less suited to this type of operation as they have less flexible response capacity.

2. Electricity prices do not provide sound justification for stretchout operation.

The myth: Unless the nuclear power plants remain in operation, electricity prices will continue to rise.

Electricity prices are formed in the European market. Prices are currently very high, not only for peak-load electricity, where gas-fired power plants determine the price in line with the merit order principle, but also for baseload electricity, which is supplied by nuclear, hydro and coal-fired power plants and does not involve the use of gas at all. This rise in baseload prices is of far greater relevance to the electricity prices paid by consumers and industry and is driven by further factors.

Calculations by the Oeko-Institut show that operating the Isar 2 and Neckarwestheim nuclear plants in stretchout mode would have minimal impact on wholesale electricity prices, resulting in a price decrease of just 0.5-0.8%.

The truth, then, is that operating the German nuclear power plants in stretchout mode would not have a significant impact on electricity prices.

Also true: A major cause of the high electricity prices is the current crisis in the French nuclear industry. Due to acute corrosion-related safety issues and ongoing reviews, 32 of France’s 56 nuclear power plants are currently offline; some reactors were unable to operate at full capacity during the very hot and dry summer. France also saw a sharp fall in electricity production at its hydropower plants – 4 TWh in June 2022, compared with 6 TWh last year. As a result, the shortfall in French nuclear and hydroelectric power in June amounted to 9.6 TWh. By comparison, Germany’s lignite-fired power plants generated around 9 TWh of electricity in June.

This has an impact on wholesale prices in Europe’s power exchange: one megawatt hour of power for December in France is currently trading at more than 1,600 euros, compared with just 86 euros a year ago. Germany has already exported around 10 TWh of power to France this year – a substantial expansion of its exports to France; in 2020, net exports stood at 1.6 TWh, while the figure for 2021 was 6.5 TWh.

3. In winter 2022, electricity grid stability would only be at risk in very extreme scenarios.

The myth: We can only maintain the stability of the electricity grid if the nuclear power plants remain in operation.

The second stress test has revealed that an overlap of various extreme scenarios could potentially cause several hours of crisis in the electricity system during the year, with possible power outages and a requirement for additional measures to meet demand. An extreme scenario might mean that the French nuclear power plants remain offline, fossil fuel replacement power plants in Germany are only partially available, or there is no rainfall for the rest of the year and low river water levels adversely impact coal deliveries into December.

The stress test therefore proposes a package of measures to avoid this network congestion. They include the use of reserve capacities at fossil fuel power plants, contractual load management and the purchase of power plant capacity in other European countries. In a very extreme scenario, the continued operation of the nuclear power plants could reduce demand at these redispatch power plants in other countries by 0.5 gigawatts (GW) (assuming that total demand for redispatch capacity is 4.6 GW). In a potentially extreme scenario, the two nuclear power plants in the deployment reserve could then make a modest contribution to grid stability; however, other measures are far more important. It will not become clear until later this year whether such extreme scenarios will indeed occur. For that reason, a decision on whether the extreme scenarios have become reality shall be postponed until December; the two standby nuclear power plants would then resume operations. If that eventuality occurs, the nuclear power plants shall run until the fuel is spent or until the plants are shut down no later than mid-April.

The truth: Careful planning is therefore the right approach, factoring in all eventualities and aligning the deployment of the remaining nuclear power plants exclusively to technical needs under extreme conditions.

Also true: Such extreme scenarios are unlikely over long periods. It would therefore be preferable to restrict the nuclear power plants’ deployment as reserve capacity for network stabilisation to periods when these plants are genuinely needed. If it is decided in December that extreme conditions justify the nuclear power plants’ continued operation with the remaining fuel reserves, there must, at minimum, be monthly reviews to determine whether the circumstances still warrant their remaining online.

4. Neither the stress test nor energy supply security and electricity prices justify a multi-year lifetime extension for the nuclear power plants with new fuel elements.

The myth: Germany relies on the nuclear power plants for electricity generation.

By the following winter, many of the factors now being considered in the stress test scenarios will have been resolved. For example, there will be more options for load management, a further increase in renewable energy capacity and more LNG terminals to handle gas imports. The current crisis in the French nuclear industry shows that these plants by no means guarantee energy supply security and that nuclear facilities whose safety reviews are well overdue have a high risk of failure.

The truth: There is therefore no technical justification for continuing to operate the nuclear power plants beyond winter 2023.

Also true: Due to Russia’s warmongering, we face a new threat scenario. Nuclear power plants are not designed to withstand military assaults, and cyber attacks also pose a threat. For that reason, high-risk facilities such as nuclear power plants have become less safe and secure since the attack on the Ukrainian plants, as every nuclear facility in Europe has become a potential military target. The risk of catastrophic accidents has increased once more. Any extension of the lifetimes of German nuclear power plants increases the security risks.

5. EU emissions trading ensures that total carbon emissions do not increase.

The myth: We can only reach Germany’s climate targets if we keep the nuclear power plants in service for longer to replace electricity generation in coal-fired power plants.

If the gas crisis means that less electricity is produced by gas-fired power plants, more coal-fired power plants will have to be deployed to generate electricity over the short term. Climate-damaging greenhouse gas emissions will therefore increase for a limited period. One of the characteristic features of European emissions trading at present is the surplus of allowances. Increasing power generation by coal-fired plants will reduce this surplus, so these allowances will no longer be available for future use. The European system also imposes an upper limit (cap) on permissible emissions, ensuring that in terms of the overall balance, the total emissions produced by power generation facilities and industry do not increase.

The truth: Emissions trading at European level therefore ensures that climate targets are met.


Summary and alternative responses to the gas crisis

It is clear from the facts set out above that there is no need for continued operation of the nuclear power plants in response to the gas crisis. At the same time, there is no doubt that we will have to resort to alternatives this winter in order to safeguard the supply of heat and power. From the Oeko-Institut’s perspective, the following measures will be required:

1. Full gas reservoirs

Germany’s gas storage levels had reached 84 percent by 2 September 2022. This means that the 80 percent storage target for October, stipulated in the Gas Storage Fill Level Act (Gasspeichergesetz), has already been met. With full reservoirs, current average gas consumption can be covered for approximately two winter months. Other EU countries with larger gas storage capacities such as Italy, France, the Czech Republic, Poland and Spain have also filled up their storage facilities in recent months and have, for the most part, achieved the EU’s 80 percent storage target for November 2022. The German Federal Network Agency reports that, although the supply of gas via the Nord Stream 1 pipeline is currently at a standstill, the process of filling the reservoirs is continuing.

2. Activation of fossil fuel power plants from the reserve

Coal- and oil-fired power plants which are currently on standby or provide reserve grid capacity can be put back into operation on a temporary basis as a substitute for heat and power generation from gas. Under the Replacement Power Plant Readiness Act (Ersatzkraftwerkebereithaltegesetz – EKBG), there is the option for 17 (mainly coal-fired) power plants with capacity of 10.5 GW to be brought back into service; according to the BDEW, these reserve power plants can generate around 7 TWh of electricity. To achieve this target, swift and comprehensive preparations must be made; this includes stockpiling the necessary fuel, providing staff, verifying the plants’ technical status and achieving compliance with air pollution limits.

3. Short-term solutions: gas- and energy-saving

In industry

There is major potential for energy-saving in industry, which needs to be harnessed. The initial response to the price rises over recent months has indicated that this is feasible. For example, gas consumption in industry in the first six months of 2022 stood at 497 billion KWh – around 15% less than in the same period last year. In June 2022, adjusted gas consumption was approximately 23% – almost a quarter – lower than consumption in June 2021. A significant proportion of these gas savings was achieved through a shift to other fuels or via relocation of production sites, as these examples show:

  • BASF in Ludwigshafen is able to substitute oil for around 15% of the natural gas it uses for heat and power generation. It has also relocated some of its ammonia production to manufacturing sites in the US.

  • Glass manufacturer Wiegand-Glas has switched its furnaces over to fuel oil.

  • Toolmaker Würth has converted its furnaces from gas to electricity.

  • The Veltins brewing company has switched from gas to fuel oil.

  • Steel producer ArcelorMittal has arranged for base products with high gas consumption to be manufactured in Canada.

Other genuine savings potential must be utilised in future, such as reductions in gas losses or efficiency increases through improved factory control systems.

In private households

Private households can save gas and oil in the short term by lowering the room temperature, reducing their hot water consumption, installing smart thermostats, performing controlled ventilation and carrying out hydronic balancing of their heating systems. For example, reducing the room temperature by one degree during the period when heating is in use achieves an energy saving of 5-6%. In the medium term, apartments and houses should undergo energy upgrading in order to achieve further reductions in energy demand. The increase in living space per capita should also be curbed in future.

4. Medium term: expansion of renewable energies and hydrogen

The expansion of renewable energies is an important alternative, as is the development of the hydrogen industry. Here, expediting the issuing of permits, as has been done for the LNG terminals (see Section 5), would be a major step so that the installation of the planned wind and solar facilities can go ahead no later than next year. Here, the Oeko-Institut has put forward proposals on Expedited planning and approval procedures for wind energy expansion.

5. Short and medium term: new LNG terminals

Until Germany is able to wean itself off Russian natural gas entirely, imports of liquefied natural gas (LNG) are to secure part of the supply in the short to medium term. For this purpose, Germany requires specialised LNG terminals, including the requisite infrastructural links, which have yet to be built. With the LNG Acceleration Act (LNG-Beschleunigungsgesetz), capacity and infrastructure for LNG imports are being created at various locations. In total, the German government has chartered five floating LNG terminals. The first two will be available at the Brunsbüttel and Wilhelmshaven sites in winter 2022/2023. Three further floating terminals will be in operation by the end of 2023. In addition, a private initiative will establish a terminal in Lubmin by the end of the year. Together, the LNG terminals will be capable of meeting around one third of current gas demand by winter 2023/2024.


Anke Herold is the Executive Director of the Oeko-Institut. She was previously an EU negotiator at the international climate negotiations under the United Nations Framework Convention on Climate Change (UNFCCC). Hauke Hermann is a Senior Researcher in the Energy and Climate Division. His areas of expertise include Germany’s power plant sector.

Further information

Blog article: Energy policy in times of the Ukraine war: Nuclear power instead of natural gas?

FactcheckNuclearPower, in this blog

no comments

New comment

* Required fields