Solar power curtailments spread across Europe in early May

Solar photovoltaic power has been massively curtailed in European markets in early May due to excessive output during noon hours, as midday hourly settlements have been deeper into negative territory, according to data from the electricity market operators.

Curtailments in the Spanish market have capped solar production below 14 GW between 11 am-5 pm local time during the weekends of May.

As much as 12 GW of solar power in the country could have entered the grid on May 11 -- considering an output high of nearly 20 GW hit on April 25 --, when the OMIE hourly price reached an all-time record low of minus Eur15/MWh for dispatching at 4-5 pm local time.

Similarly, some 3.5 GW of solar have been cut off from the French grid since last weekend. Solar power in Germany was capped at around 40 GW in the early afternoon of May 11, with curtailments doubling year over year.

"Renewable support mechanisms play a role in the level of price-led solar curtailment seen with Spain, for example, seeing high levels of curtailments due to the majority of its solar fleet being exposed to market prices," said Annika Amin, lead European power analyst at S&P Global Commodity Insights. "Further, most markets are also sensitive to curtailment of solar in their neighboring markets due to differences in scale of capacity and subsidy schemes."

The weekend of May 10-11 saw some of the lowest hourly prices ever recorded in Europe, with the Belgian EPEX clearing at a record low of minus Eur462.33/MWh for 1-2 pm local time on May 11. At that same time, German and Swiss equivalents were at minus Eur250.32/MWh and minus Eur262.21/MWh, respectively, while the Netherlands settled at minus Eur350/MWh.

Platts, part of Commodity Insights, has assessed eight negative daily solar capture prices for Spain this year, compared to just one on June 2, 2024.

Similarly, there have been eight German daily solar capture assessments in 2025, down from 17 instances in all of 2024, following a significant drop to their lowest level in April since the Covid-19 pandemic.

Spain and Germany are expected to have 114.3 GW and 39.5 GW of solar installed capacity by the end of this year, according to the latest S&P Global Commodity Insights' data.

Spanish, Portuguese hourly settlements continue to diverge

The OMIE hourly spread between Spain and Portugal has been over Eur14/MWh Portuguese premium so far this month.

That compares with Portugal averaging a discount of 90 euro cent/MWh to Spain across April.

The Portuguese premium to Spain has been expanded, particularly when the latter goes negative, with such spread going beyond Eur40/MWh in midday between May 5-8.

But the largest Portuguese premium was hit at Eur63.39/MWh for May 6 at 7-8 pm local time.

In May, Spain has commercially exported to Portugal about 460 MW at 2-3 pm local time, compared with a monthly average of 316 MW.