Negative Prices Give Batteries a Business

French solar power sold at a steep discount to the average power price in April. Pexapark says France's solar capture factor fell to around 0.10 in April 2026, down from roughly 0.42 in April 2025, a 75% drop year-on-year. A farm that took 0.42 of the average price a year earlier now takes 0.10.

That collapse is the raw material of a new business. Cheap midday power and expensive evening power are the two ends of a battery's spread, and in Iberia and France the gap is widening faster than the steel can arrive.

The spread

Storio Energy's September price monitor puts a number on it. The average daily spread on the French spot market reached €214 ($240.7)/MWh, a level not seen since 2022, as relayed by pv magazine. Storio's illustration is a 1 MW/2 MWh battery that charged at an average of €73/MWh in September and discharged at €232/MWh, completing around 1.5 cycles a day. "It generated 135% more spot revenue compared to September 2025." Storio said of that unit. Its summary of the month: "Price volatility is skyrocketing."

The supply side explains the swing. Europe produced 129 TWh of solar electricity in the second quarter of 2026, almost 20% more than in any previous second quarter, pv magazine reported on July 15. That is a record, and the grid is struggling to absorb it. On May 1, with low holiday demand and reduced nuclear flexibility, the French spot market hit a low of -€498/MWh, according to pv magazine.

Spain shows how fast the problem is spreading. Pexapark's analysis found negative price hours there surged to 148 in February 2026 from zero the year before, a sign that oversupply is now appearing in winter. In April, negative pricing rose from 117 to 138 hours, and the share of Spanish solar output sold during negative periods climbed from 35.2% to 41.2%. Pexapark's David Battista writes that solar deployment is now advancing faster than system flexibility.

Germany shows the other side of the swing. Montel data cited by pv magazine show evening peak prices surging above €600/MWh, while in late April some European markets approached the technical floor of €-500/MWh, later lowered to €-600/MWh. Pexapark counts a longest continuous negative stretch in Germany of 17 hours in April 2026, up from seven hours in April 2025. A battery that buys through that stretch and sells into the evening does not need a subsidy to make its case.

Why the spread persists

If batteries earn this much, why haven't they flattened it? Because there are too few. Pexapark says current BESS penetration is too limited to materially compress day-ahead spreads or absorb large midday surpluses at the system level. It also notes that France and Germany recorded some of the sharpest increases, with April day-ahead spreads expanding by roughly 20%.

Behavior matters too. Montel's report, relayed by PV Magazine, says some flexible thermal plants, storage operators and industrial consumers declined to bid at negative levels in day-ahead auctions. They held capacity back for intraday or balancing markets instead. Flexibility is being sold, but not always where the price signal is loudest.

The pipeline

Money is following the signal. SolarPower Europe's release of 23 June 2026 says Europe's battery market continued its record-breaking trajectory in 2025, with 36 GWh installed and a twelfth consecutive year of growth. The market expanded by 48%, driven by utility-scale projects, and total operational capacity passed 100 GWh for the first time. Energy Storage News, citing the same outlook, reports utility-scale deployment reached 19 GWh in 2025, up from 9.7 GWh in 2024. Ees Europe's summary puts European BESS investment at €17 billion in 2025, a 20 percent increase.

The ees Europe summary also ties this to prices. It says negative prices rose from less than 0.5 percent of the year before 2022 to 3.4 percent in 2025. It adds that the strongest increases in volatility have come in markets such as Germany, Poland and Spain, where renewables have outpaced flexibility.

The geography is shifting. Germany, the UK and Italy remain the largest markets, but their combined share of new installations fell to 47%, from nearly 80% in 2023 and 2024, Energy Storage News reports. EUPD Group says the UK and Spain are scaling quickly through front-of-the-meter pipelines. By 2030, ees Europe says, Spain and the Netherlands are expected to join the leaders in the top five.

Still short

The forecasts are large and still not enough. SolarPower Europe expects annual installations to exceed 50 GWh in 2026 and rise to 138 GWh by 2030, a path the association sets against 2025 levels. Within the EU-27, the fleet is projected to reach around 470 GWh by decade's end. The association says that growth still falls short of what is needed by 2030 in an ideal scenario. Industry estimates cited by ees Europe say the EU would need at least 600 GWh by 2030 for a highly renewable, electrified system.

The residential segment is smaller still. EUPD Research expects roughly 15 GWh of new home battery capacity in Europe in 2026, per PV Magazine.

SolarPower Europe CEO Walburga Hemetsberger put the gap diplomatically: "Europe's battery market is moving in the right direction, but we are not yet where we need to be." The association wants a dedicated Battery Storage Action Plan from EU policymakers. Its senior market analyst Antonio Arruebo was more cheerful at the report launch: "We are radical optimists when it comes to the growth of batteries in Europe."

Optimism is cheap. Spreads are not, and they will stay wide only while batteries stay scarce. Every project that reaches the grid narrows the gap that pays for it. For now, the midday sun is selling at a loss and the evening is sold dear.