Week 25 shifts focus from baseload to evening price spreads
Week 25 in the SEE power market highlighted that the key commercial price signal is no longer the average daily baseload price. Instead, it is the spread between solar-heavy midday hours and the evening delivery window. The most critical block is increasingly 18:00–23:00, when solar generation exits the system while cooling demand remains active.
During the same week, solar generation rose 8.1%, which helped soften midday pricing. Wind declined by 4.4%, while hydro weakened across several markets and thermal output had to rise sharply. The resulting price curve left midday electricity comparatively comfortable, while the evening market repriced around flexibility.
How an evening block premium index would measure value
An evening block premium index would track the transition in real time by comparing prices between midday hours and evening scarcity hours. The measurement would cover Serbia, Hungary, Romania, Croatia, Greece, Bulgaria and Italy. It would indicate where the highest value is being created for batteries, flexible hydro, gas plants and shaped PPAs.
The index design would be aligned with the changing timing of supply and demand described for Week 25. It would focus on how prices move from solar-influenced periods into the 18:00–23:00 window. This approach reflects the shift away from a single daily reference point toward hour-specific scarcity pricing.
Implications for renewables, storage and industrial contract structures
The index would be used by renewable developers to assess merchant revenue sensitivity to intraday spreads. For solar projects, revenue would depend increasingly on the difference between prices captured during production hours and prices paid later in the day. For batteries, the same spread would apply in reverse through charging into weaker daytime prices and discharging into evening premiums.
For industrial buyers, the index would highlight risk embedded in flat contracts that do not fully account for expensive hours. A buyer may secure annual volume but still remain exposed to the most expensive delivery periods unless supply arrangements include shaping or balancing. SEE electricity is described as becoming an hourly market, with the evening premium identified as a new stress signal.
