Nuclear power plant shutdown This is how much electricity will be lost with Beznau and how it is to be replaced

Axpo plans to take the Beznau nuclear power plant off the grid in 2033. The Swiss electricity system will then have to generate a considerable amount of energy from other sources - or import it.

In 2033, after 64 years of operation, the Beznau nuclear power plant will be decommissioned. Axpo is not willing to make further investments to keep the oldest nuclear power plant in operation for much longer.

The reactions to the decision show the dominant positions in Swiss energy policy.

There are no two opinions on this question: The two reactors Beznau 1 and 2 supply around 6 terawatt hours of electricity per year. Half of this is generated in winter, as Axpo CEO Christoph Brand explains to the "Aargauer Zeitung" newspaper. The output in winter is particularly important, as solar power plants supply less at this time.

It should be noted that the last Swiss nuclear power plants - Gösgen and Leibstadt - will also be taken off the grid by 2050. That is another 22 terawatt hours of electricity per year that the Swiss energy system will have to replace. In addition, electricity demand is forecast to increase by 30 to 50 percent by 2050.

End of nuclear power plant after 64 yearsAxpo wants to shut down Beznau nuclear power plant for good in 2033

The Association of Swiss Electricity Suppliers (VES) is certain: in winter 2033/2034 there will be an electricity shortfall equivalent to the 3 terawatt hours of electricity mentioned.

The nuclear-critical Swiss Energy Foundation SES disagrees: The expansion of solar energy is taking place so quickly that it will replace the output of the Beznau reactors and the already decommissioned Mühleberg nuclear power plant before 2030 - even in winter.

Economiesuisse calculates that current solar energy generation would have to be increased by 150 percent to compensate for Beznau. In addition, due to the fog and short days, electricity storage capacity in the order of magnitude of all pumped storage power plants in Switzerland would have to be available in winter.

In principle, the electricity suppliers and the federal government have a roadmap for the energy transition. However, quite a few of the projects for more electricity from the sun, wind and water are facing objections. The solar express has come to a standstill, there is strong opposition to wind turbines and the raising of dam walls is not without controversy.

Grid as a bottleneckWhy the feed-in of solar power should be slowed down

Renewable-friendly organizations such as SES and Swissolar are convinced that the expansion is fast enough (see above). Solar plants currently generate around 6 terawatt hours, i.e. the same amount as the Beznau nuclear power plant. From 2027, 2 gigawatts are to be newly installed each year. However, the problem of storage remains, as solar power is only generated during the day and when it is not too cloudy. In addition, the electricity grid must be expanded in order to be able to absorb the energy from the many decentralized systems and direct it to where it is needed.

The VES refers to the Mantel Decree, which aims to expand hydropower by 2 terawatt hours. The Association of Electricity Suppliers does not believe that these energy sources can cover the missing one terawatt hour with solar and wind energy. This is also because the electricity grid cannot be expanded quickly enough.

Switzerland already exports and imports electricity. It will continue to do so. In 2023, it supplied 33.8 terawatt hours abroad and purchased 27.5 terawatt hours from abroad.

The SES points out that prices on the international energy exchanges are low, which indicates a sufficient supply of electricity in the coming years. However, this can change quickly, as the months following the Russian invasion of Ukraine have shown. At the time, there were fears of an electricity shortage in Switzerland, which ultimately did not materialize.

Switzerland voted to phase out nuclear power in 2017. The resulting law is in force, even though the Federal Department of Energy, under the leadership of Federal Councillor Rösti, has made preparations so that the ban on new nuclear power plant construction could be lifted.

However, it is clear that the nine years until Beznau is shut down will be nowhere near enough time to democratically approve, plan and build a new nuclear power plant. Both supporters and opponents of new nuclear power plants in Switzerland share this view. The most optimistic time frame is 20 years until commissioning.

Opting out of the nuclear phase-outA new Swiss nuclear power plant would be a major economic risk

The pro-nuclear VSE points to the small modular reactors being developed in other countries, which could be connected to the grid much faster. These are "the only hope" for Switzerland. If they become marketable in time, Switzerland could start building them at the end of the 2020s, according to the VSE.

The nuclear-sceptic SES, on the other hand, sees the end of Beznau as the next step in Switzerland's nuclear phase-out. The accelerated expansion of renewable energies will enable this to continue. The Gösen and Leibstadt nuclear power plants will remain on the Swiss grid from 2034.