SEEPEX, Serbia’s power exchange, introduced negative electricity prices for delivery from 6 May 2026, creating a new market signal for flexibility. The shift came as prices could also exceed EUR 300/MWh during scarcity, widening the range of outcomes for generators and investors. The contrasting conditions raised the importance of managing exposure to changing market prices.
The first negative day-ahead clearing price followed on 10 May 2026, for the 14:00–15:00 delivery hour. SEEPEX recorded a price of -EUR 0.01/MWh, with 673.4 MWh traded during that hour. The result marked the first negative day-ahead price on the Serbian exchange.
Later in May, the first negative intraday trades were recorded, with a volume-weighted average price of -EUR 8.83/MWh for one delivery hour. The initial negative prices were followed by high autumn readings: on 30 October 2026, SEEPEX baseload reached EUR 303.29/MWh and peakload reached EUR 331.30/MWh. Trading volumes in October were above half a terawatt-hour.
The spring surplus signals and autumn scarcity illustrate why storage is no longer assessed only as infrastructure supporting renewable generation. Negative prices increase the value of flexible charging, but the hours remain limited and can be unpredictable. Buying electricity during those periods alone therefore does not provide a durable commercial strategy for developers.
Storage can instead help manage a portfolio across day-ahead, intraday and balancing markets. Batteries can be available to respond when market prices move away from the central forecast, connecting flexibility to more than one market interval. The value lies in managing changing price conditions rather than relying solely on the availability of negative-price hours.
Negative prices also expose fixed-output renewable projects to capture-price risk. A co-located or contracted battery can protect some of that downside, while flexible charging creates another potential use for storage. Serbia’s first year of negative prices has strengthened the investment case for storage and raised the analytical standard for renewable projects financed without it.
