Winter 2022/2023

Responsibility for the security of supply in Switzerland is shared by various players. As the national grid company, Swissgrid is responsible for ensuring the non-discriminatory, reliable and efficient operation of the transmission grid.

The Federal Council has enacted various measures to increase the security of supply in the short term and has assigned new roles to Swissgrid.

Swissgrid is working closely with partners in Switzerland and abroad and doing everything it can to contribute to Switzerland’s secure and reliable supply of electricity. Ensuring secure grid operation is an absolute priority for Swissgrid. At the beginning of July 2022, Swissgrid set up an internal task force that continuously monitors and analyses the current situation and plans possible measures on the basis of various scenarios.

Hydropower reserve

The Federal Council has decided to establish a hydropower reserve for the winter of 2022/2023. The measure contained in the Federal Act on a Secure Electricity Supply from Renewable Energy Sources (consolidation legislation) has been brought forward by ordinance. The Federal Council will bring the hydropower reserve into force on 1 October 2022. The auction will take place at the end of October 2022.

In exchange for a fee, storage power plants will retain a certain amount of energy, the hydropower reserve, that can then be requested when needed. This reserve is intended to bridge a period of a few weeks towards the end of winter when there are fewer import possibilities and lower availability of domestic production. The Swiss Federal Electricity Commission ElCom expected a magnitude of 500 GWh plus or minus 166 GWh. The hydropower reserve is to remain in place from 1 December 2022 until 15 May 2023.

In the auction, which took place at the end of October, a total energy volume of 400 GWh was procured at an average price of EUR 739.97/MWh. The Federal Electricity Commission (ElCom) has examined the tenders and approved the awarding of contracts. The costs for the reservation of water («reserve charges») are financed by Swissgrid via a separate tariff. It can be assumed that Swissgrid’s tariffs will increase significantly as a result.

In exchange for a fee, storage power plants will retain a certain amount of energy, the hydropower reserve.
In exchange for a fee, storage power plants will retain a certain amount of energy, the hydropower reserve.

The Federal Council has transferred the operational management of the hydropower reserve to Swissgrid by ordinance. Consequently, Swissgrid is taking on a new role that goes beyond its previous legal mandate. In specific terms, Swissgrid is providing the IT systems for handling the auction and the requests. Swissgrid was also entrusted with defining and organising training for all processes, conducting the auctions and overseeing the accounting. This requires close cooperation with the industry and new contracts.

The reserve will be used when the supply on the market on the day before delivery can no longer cover demand, i.e. when the market does not close. The market player whose demand cannot be met reports its requirements to Swissgrid. Swissgrid then requests the necessary reserve power from the reserve providers.

Against the backdrop of the current geopolitical situation, the lack of an electricity agreement with the EU and the slow approval procedures for the construction of production plants and grid infrastructure, the hydropower reserve is a comprehensible and feasible measure to ensure the security of supply.

In the medium and long term, further measures are needed to effectively counteract shortages of electricity. Swissgrid has drawn up appropriate proposals with the authorities and the industry. They include building additional domestic production capacity, accelerating procedures for the necessary expansion of production plants and grid infrastructure, and negotiating an electricity agreement with the EU.



Temporary voltage increase on the Bickigen – Chippis and Bassecourt – Mühleberg lines

The Federal Council has enacted various measures to strengthen security of supply in the short term. These measures are ready to be implemented in the coming winter in order to deal with extraordinary and critical situations. They include plans for temporary voltage increases on the Bickigen – Chippis (Gemmi line) and Bassecourt – Mühleberg transmission lines.

To prevent congestion in the transmission system in the coming winter, the Federal Council is allowing a temporary increase in the operating voltage of the two transmission lines between Bickigen and Chippis (Gemmi line) and Bassecourt and Mühleberg from 220 kilovolts (kV) to 380 kV in the period from January to April 2023. This will relieve congestion in the Swiss transmission grid so that the energy from the pumped storage power plants in the Alps can be transported in full to Central Switzerland. In an emergency, Swissgrid can increase the transfer capacity of the extra-high-voltage grid on the basis of criteria set by the federal government.

Test operation at a voltage of 380 kV

Swissgrid is making the necessary technical preparations to operate the Bickigen – Chippis and Bassecourt – Mühleberg lines at a voltage of 380 kV on a temporary basis in the event of a tense supply situation. The measure is only planned for the period between January and April 2023. Test operations will take place on both lines between mid-December 2022 and the end of February 2023. This will involve temporarily changing the voltage of the existing lines from 220 kV to 380 kV. The test operation with 380 kV will only be carried out if the grid situation allows it. The combined test operations will verify the lines from an operational point of view. The two voltage increases influence each other and can shift congestion depending on grid utilisation. The scope and duration of the test operations were approved by the Federal Inspectorate for Heavy Current Installations (ESTI).

Bickigen – Chippis
Swissgrid is making the necessary technical preparations to operate the existing Bickigen – Chippis 220 kV line at 380 kV on a temporary basis. Two 220 kV lines are currently connected via the electricity pylons along the Bickigen – Chippis route. For the temporary voltage increase, all phases will be shifted by one position so that the 220 kV line is on the lowest cantilever. The line systems on four electricity pylons in the vicinity of the Bickigen, Chippis and Wimmis substations have been transposed especially for this purpose (see information sheet). The line lead-ins to the Bickigen and Chippis substations have also been modified. This will minimise the impact on people and the environment as much as possible and ensure that the safety distances between the conductors and the ground, houses or cableways can be observed. The voltage change will slightly increase the noise level. The planned line modifications required for the permanent voltage conversion to 380 kV are currently in the approval process.

Bassecourt – Mühleberg
Swissgrid had already successfully tested the operation of the Bassecourt – Mühleberg line and the transformer in Mühleberg at a voltage of 380 kV in autumn 2021. This means that Swissgrid will be technically ready to operate this line at 380 kV on a temporary basis in the event of a critical supply situation. The planned construction measures necessary for the permanent voltage change to 380 kV are being carried out in two stages from mid-August 2022 until the end of 2023.


Grid connection of the reserve power plant in Birr

Every unused kilowatt hour counts. It is not only important to save electricity, but also to increase generation capacity. This is the conclusion of a report that Swissgrid prepared in association with the industry and that was presented to the administration and politicians at the beginning of the year. Swissgrid therefore welcomes the Confederation’s efforts to bring a strategic reserve onto the grid in the form of a back-up power plant.

A reserve power plant of this kind, consisting of eight modular, mobile gas turbines, each with around 30 megawatts of power, totalling almost 250 MW, is being installed on the premises of General Electric (GE) in Birr (AG). The turbines can be operated with various gaseous and liquid fuels. The Federal Council has issued an ordinance to govern the deployment of these reserve power plants. The use of energy is managed by Swissgrid. These energy reserves can be used as needed in extraordinary shortage situations until the end of April 2026..

A grid connection in record time

Swissgrid had to establish a new grid connection in order to feed the energy from the mobile gas turbines into the transmission system via the 220 kV substation in Birr. The grid connection for the Birr reserve power plant has been ready since 24 February 2023. Swissgrid took less than six months to set up the grid connection, which is something that usually requires several years. Implementing a project of this kind under extreme pressure in just a few months was a huge challenge for the project team and the commissioned suppliers and service providers. Firstly, it required the corresponding infrastructure components such as switchgear and lines. In addition, before the Birr reserve power plant was commissioned, extensive contractual negotiations on operational aspects in relation to the reserve power plant were necessary with the federal government and the operating company within a short period of time. Keeping people safe was the highest priority for Swissgrid. Everything was done to ensure that occupational safety was guaranteed at all times.

Control energy for secure grid operation

Electricity cannot be stored in the transmission grid, so the amount of electricity fed in must always be the same as the amount of electricity fed out. This means the production and consumption of energy must always be balanced. This equilibrium guarantees the secure and stable operation of the grid at a constant frequency of 50 hertz. If unforeseen fluctuations arise, the operators in the grid control rooms use control energy, a reserve that power plants keep available for Swissgrid and that can be retrieved as required. The power plants either increase or decrease their power to compensate for any missing or excess electrical energy. Even if electricity becomes scarce in the winter of 2022/2023, Swissgrid must be able to provide sufficient control power. For this reason, procurements were made at an early stage to prepare for the winter.

The employees in the two control rooms in Aarau and Prilly monitor the entire Swiss transmission grid around the clock.

Emergency power groups

At its meeting on 19 October 2022, the Federal Council opened the consultation on the Ordinance on the Establishment of a Winter Reserve (Winter Reserve Ordinance). The consultation will last until 18 November 2022, and the ordinance is intended to enter into force by mid-February 2023 at the latest.

It regulates the use of emergency power groups as an additional reserve alongside the hydropower reserve and reserve power plants.

The use of emergency power groups as an additional reserve for the coming winter is being substantiated. At its meeting on 9 November 2022, the Federal Council approved further work on the implementation of this reserve. The aim is to contract emergency power groups to provide a total capacity of around 280 MW.

The SFOE launched a call for tenders to find suitable aggregators to participate in the reserve with which it could conclude contracts. The call for tenders has been completed. The Confederation has signed contracts with Axpo, BKW and CKW for a period of four years with a total budget of CHF 1 million.

As aggregators, these three companies are responsible for setting up a virtual national reserve power plant, consisting of emergency power groups. The holders of these emergency power groups voluntarily agree to make them available in return for remuneration. They can register now with the three aggregators.

As with the hydropower reserve, Swissgrid will be responsible for the operational management and is preparing itself accordingly.

Interconnection with Europe

The Swiss transmission grid is part of the European interconnected grid and is connected to neighbouring countries via 41 cross-border lines. The close meshing of the electricity system and cooperation with European partners to date make a significant contribution to Switzerland’s security of supply. Close cooperation with partners in Europe is of the utmost importance for system security in Switzerland and in neighbouring European countries with regard to the winter of 2022/2023 as well. Electricity self-sufficiency would not mitigate the risk of a power shortage.

If Switzerland were to operate as an island, the entire reserve for a power plant failure in Switzerland would have to be available within Switzerland itself. It would have to be possible to compensate outages of big power plants at any time. With a grid load of 10 GW in winter and 5 GW in summer, 10 to 20 percent of power would be lost with the outage of Leibstadt. This would have a massive impact on frequency. The drop would be striking and would cause a grid disturbance. This would lead to a partial to complete power system failure.

An island solution would jeopardise both secure grid operation and the security of supply. The legislator took the importance of interconnection with Europe into account in the Electricity Supply Act. Cooperating with the European transmission system operators and ensuring sufficient international interconnection of the Swiss transmission grid represent an explicit legal mandate for Swissgrid (Art. 20, Para. 2, lit. f StromVG).

Close cooperation with European partners requires a political or intergovernmental solution. This is the only way to establish a stable framework for secure cooperation with the EU in the long term, and hence for a high level of security of supply in Switzerland.

Close cooperation with European partners requires a political or intergovernmental solution.

Lessons learned from the winters of 2015/2016 and 2016/2017

In the autumn of 2015, it became apparent that the energy and grid situation for the winter of 2015/2016 would be strained. Energy reserves in Switzerland were scarce at that point in time due to a series of specific circumstances.

In the «Strategic Grid 2025», Swissgrid planned the grid that Switzerland will need until the reference year 2025, taking into account the Energy Strategy 2050. It makes provision for additional transformers in Mühleberg, Beznau, Chippis, Mörel and Romanel. The urgency of the rapid implementation of the associated construction projects was confirmed by the situation in the winter of 2015/2016. Swissgrid has installed additional transformers in Mühleberg, Beznau, Chippis and Romanel in recent years. However, some of them cannot yet be used as intended due to slow-moving grid projects, as transformation is only possible when 220 kV and 380 kV voltage levels meet in the substations. Accelerating the approval procedures for the construction of new lines is therefore an important concern for Swissgrid.



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