Stock exchange: record for hours with negative electricity prices

In May 2025, electricity was traded at negative prices on the EPEX Spot electricity exchange more often than ever before, according to the company 1Komma5°. This means that electricity producers had to pay money for someone to buy their surplus electricity. So far in May 2025, there have been a total of 112 hours in which the electricity price on the EPEX Spot exchange was below zero cents per kilowatt hour (kWh). In comparison: ten years ago, in May 2015, there were only 21 hours. In May 2024, which held the record until then, there were 78 hours with negative prices.

The figures were published on Wednesday by the Hamburg-based clean tech company 1Komma5°, which has been analyzing the market since 2015. There is unlikely to have been a higher figure before. On average, the negative prices so far this May have been around -1.90 cents per kWh. On May 11, 2025, the price even fell to an extremely low -25 cents per kWh at 1 pm. Negative electricity prices occur when much more electricity is produced than can be consumed at the time. The operators of conventional power plants still have to get rid of their production volume. This is why they accept short-term discounts.

Why are negative electricity prices on the rise?

Jannik Schall, co-founder of 1Komma5°, explains that negative electricity prices often occur at lunchtime, especially when the sun is shining brightly. This is when solar panels on roofs and fields produce a lot of electricity. As there are generally a lot of hours of sunshine in May due to favorable weather conditions, negative prices occur more frequently in this month than in others.

With the expansion of renewable energies such as solar and wind power plants, the number of hours with negative electricity prices is also increasing. In the whole of 2016, for example, there were only 97 hours with negative prices, whereas in 2024 there were already 457 hours. That is an increase of almost five times.

Deployment options for smart meters

Smart meter gateways are considered the technical prerequisite for integrating solar systems, storage systems, electric car charging stations and heat pumps into the electricity market. This allows solar operators to sell their surplus solar power profitably on the exchange when electricity is scarce and therefore expensive. At the same time, they will be able to draw electricity from the grid and charge their storage system or electric car precisely when electricity is plentiful and the price on the exchange is therefore favorable or even negative.

The Federal Council passed the Solar Peak Act in mid-February: Operators of new solar systems will no longer receive feed-in tariffs when electricity prices are negative and smart meters will become more expensive for users. The main aim is to smooth out temporary electricity surpluses. Not all players will benefit from this trend. Operators of wind and solar power plants that cannot react flexibly to price signals lose income. An oversupply of electricity can also destabilize the electricity grid in unfavourable cases and requires grid operators to take measures to maintain frequency and voltage.

(vbr)