Record week on the day-ahead electricity market. Electricity prices were negative for a fifth of the time

Electricity prices on the day-ahead market fell deep into negative territory last week. On Sunday afternoon, the day-ahead market price was at its lowest level at least since 2015 (and very likely a record low over a much longer period). At 14:00, the electricity price reached -489 EUR/MWh. Negative prices began appearing as early as Wednesday last week, with nearly one-fifth of all quarter-hours during the week recording negative prices.

With sunny weather, negative electricity prices returned to the day-ahead market in full force. They occur most frequently at weekends, when electricity consumption in the country is generally lower. Last week, however, was exceptional in this respect.

The first negative prices appeared as early as Wednesday, and from then on prices fell below zero every day around noon until the end of the week. In total, prices were negative in 128 quarter-hours of the week (approximately 19 % of all quarter-hours). Including zero prices, the total would be 133, or roughly one-fifth of all quarter-hours last week.

Detailed data for last week can be found HERE.

Negative prices always occurred around noon, when output from solar power plants was high. Over the full week, they accounted for 12 % of total generation (and as much as 15 % over the weekend alone). In terms of power supplied to the grid, generation regularly exceeded 3 GW, peaking on Wednesday at 11:45, when supplied output surpassed 3415 MW. Solar power plants in the Czech Republic have generated more only once in history, shortly after noon on 7 April 2026.

The highest number of negative-price hours usually occurs at the beginning of May. In addition to favourable weather, the reason is that there are two public holidays during this period. This year, they also fall on a Friday, and this week is expected to be relatively sunny. The number of negative prices is therefore very likely to continue rising.

Negative prices affected all of Europe

Negative prices affected all of Europe on Sunday. As the map below shows, all countries around the Czech Republic had negative prices at around 14:00. In Slovakia and Hungary, prices even fell to -500 EUR/MWh. They declined only slightly in the Baltic states and on the Iberian Peninsula.

An opportunity for BESS and trading flexibility

Sharp fluctuations in day-ahead market prices are creating scope for trading flexibility and, above all, battery storage. A large number of such facilities are now under construction in the Czech Republic and, with a slight exaggeration, it can be said that Czechia stands on the threshold of a battery boom. For example, Second Foundation is building a 300 MW storage facility. Sev.en and SUAS Group are planning further large-scale storage facilities.

Although only a handful of electricity storage licences have been issued so far, a number of companies have announced projects in advanced preparation or construction, with completion scheduled for this year or next year.

Most projects are based economically on so-called trading and technical flexibility. Trading flexibility consists of taking advantage of fluctuations on wholesale markets, including the day-ahead electricity market. Put simply, battery operators store electricity during periods of negative prices (around noon) and sell it during the evening peak or at another hour with a high price.

Last week was ideal for trading flexibility. On Sunday, the price at 14:00 fell to the record level of -489 EUR/MWh, before rising again to 179 EUR/MWh less than six hours later.