Peak shaving from 2026: What it means for PV systems

The energy transition is progressing, and that is a good thing. In 2023 and 2024, around 6,000 new solar installations were connected to the grid each year in the BKW distribution network area alone. Several thousand new installations will also be added in 2025, meaning that solar power will already contribute around 14 per cent to total electricity consumption in Switzerland this year.

Maximum load – high costs

The boom also has its downsides. Because solar power is generated in concentrated amounts mainly on sunny summer days and around midday, the electricity grid can become congested at these times. This is a problem because the capacity of the grid infrastructure has to be designed for maximum output, even if this output is actually required for only a few hours in a year. Expansions of this infrastructure are expensive, and all electricity consumers bear the costs through higher grid tariffs on their electricity bills.

One way to reduce such peak loads when feeding in solar power is grid-serving feed-in control. This so-called peak shaving is expressly provided for in the Energy Act, which was clearly approved by the Swiss electorate in the 2024 referendum. The Energy Act and the associated ordinance state that grid operators have the right to curtail a maximum of 3% of annual energy without compensation.

The industry has now agreed to implement the Act and the associated ordinance as of 1 January 2026 by limiting the feed-in of PV electricity to 70 per cent of a system’s maximum output.

No restrictions on self-consumption and storage

Does this now mean that owners of PV systems have to forgo 30% of their production and revenue? The answer is clear and unequivocal: no. The law stipulates that no more than 3% of annual production may be lost. In fact, with 70% peak shaving, the loss of energy will be less than one per cent for most systems, as analyses of existing systems show.

How does this low energy loss come about? A PV system only produces at maximum output for a few hours a year. Almost always, due to the weather and the orientation of the solar installation, the output is in any case below 70% of the installed capacity, so nothing changes during all these hours. In addition, the 70% limit applies only to feed-in to the grid. Anyone who uses the electricity from a PV system in their home, for example to charge an electric car or a storage system, can continue to use all the electricity produced, just as before. This means that systems with self-consumption and an energy management system do not suffer any financial loss.

Creating space for new PV systems

The minor disadvantage of reduced feed-in is offset by important benefits. By cutting power peaks through peak shaving, unnecessary costs for grid expansion can be reduced, as fewer transformer stations, distribution cabinets and lines need to be reinforced or newly built. In addition, space is created in the existing grid for additional solar power from thousands of new PV systems that can be connected without expansion.

Peak shaving will be introduced as mandatory in the BKW grid for systems whose connection applications are submitted from 1 January 2026. Production losses will not be compensated – as stipulated in the Energy Act. Existing systems do not have to be retrofitted for the time being. Peak shaving will only be introduced when changes to the system are due (e.g. replacement of the inverter or expansion of the system). Because specialists are already on site in such cases, customers will incur hardly any additional costs as a result.

Peak shaving is important and necessary

It will continue to be necessary to reinforce and expand the grid infrastructure in the future; this is the only way the energy transition can be achieved. However, peak shaving reduces the need for this expansion and thus lowers costs, which ultimately benefits us all. That is why peak shaving is an important and necessary element in making rapid and efficient progress on the path towards the energy transition.

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