Second stress test for the electricity system

Security of supply in the German electricity system remains high despite the tense situation on the energy markets. This is shown by the results of the second stress test.

transmission tower© Adobe Stock / Gina Sanders

The reason for the review was not only the tense situation on the energy markets caused by the Russian war of aggression against Ukraine. The dry summer, low river levels which restricted coal shipments and the current loss of roughly half of France’s fleet of nuclear power plants are also impacting energy security.

Crisis situations remain highly unlikely

The four German transmission system operators 50Hertz, Amprion, TenneT and TransnetBW presented the findings of the second grid stress test (second special analysis for winter 22/23) on 9 September. They find that hourly crisis situations in the power system in the winter of 2022/2023 are very unlikely, but cannot be entirely excluded at present. Additional measures are to help keep the grid stable even in these unlikely events.

The first measures include additional power generation in biogas plants, measures to increase the capacity utilisation of the grids and steps to improve the grids’ transport capacities, and the return of coal-fired power plants to the market.

On 28 September, the federal cabinet decided that power stations from the grid reserve can remain in use for longer than previously planned due to the gas shortage (until the end of March 2024) as long as the electricity supply situation remains tense. Since the beginning of October, it has also been possible for the lignite power stations on security standby to return to the market.

Two nuclear power plants form deployment reserve until April 2023

On the basis of the findings from the stress test, it was also decided that two of the last three German nuclear power plants would be placed in a deployment reserve until April 2023.

Whether it becomes necessary to operate the plants will depend on the basic data of the grid stress test. This refers primarily to the availability of the nuclear power plants in France, the volume of coal-fired power plants back on the market, the availability of the gas-fired and coal-fired power plants, and the expected development in electricity consumption. According to the paper of principles agreed for this, the decision on the reserve operation of the nuclear power plants is to be taken before the end of this year.

In the three different scenarios of the stress test (critical scenario +, very critical scenario ++, and extreme scenario +++), possible effects of differing critical energy market situations on the electricity sector in Germany and Europe were examined. The interplay with neighbouring European countries is an important factor here since, in view of its geographical location and the fact that it has interconnectors to eleven other European countries, Germany’s energy situation is particularly affected by developments across Europe.

In comparison with the first special analysis (March to May 2022), the assumptions made about the effects on the energy market of the Russian war of aggression were much more demanding in response to the need for crisis-preparedness, and were gradually scaled up. Also, the calculations take account of other possible bottlenecks in power plant availability.

Much better situation expected for the winter of 23/24

„The situation in the electricity system this winter cannot be compared with that in the winter of 2023-24,“ Federal Minister Habeck emphasises in view of the outcome of the stress test. „Next year, the fundamentals will be different, because the measures we are taking will have had more time to work, and further steps can be taken.“

Not least, the Federal Government intends to boost import capacities for gas via floating LNG terminals (FSRUs) to such an extent for the winter of 23/24 that there will no longer be any fears of a shortage of fuel for the gas-fired power stations. More use can be made of electricity from biogas and renewable energy plants. By the winter of 23/24, the performance of the grids is to be improved, availability of power-plant capacity is to be increased, and flexible loads are to be on the market.