Southeast Europe’s electricity market entered a new phase in August as expanding solar generation pushed daytime prices lower while tightening supply in the evening drove power prices sharply higher.
Serbia provided one of the clearest examples of this growing imbalance. Average SEEPEX baseload prices increased 24.9% month on month to €136.70/MWh in August, while traded day-ahead volume rose 8.9% to 547,190 MWh.
However, the monthly average masked a far more dramatic divide between daytime and evening prices.
Electricity at hour 12 averaged just €66.11/MWh, while the hour-13 price stood at €67.06/MWh. Prices then climbed rapidly as solar generation declined. By hour 19, the average had reached €210.97/MWh, before rising to €243.65/MWh at hour 20 and €240.25/MWh at hour 21.
The average price at hour 20 was therefore almost 3.7 times higher than the price recorded around noon, highlighting the growing value of electricity delivered after solar production begins to fade.
On individual days, the imbalance was even more pronounced. On August 3, SEEPEX prices for hours 20 and 21 reached €553.04/MWh and €550.01/MWh, respectively. The following day, prices remained exceptionally high at €496.80/MWh and €475.01/MWh during the same evening period.
The emerging pattern points to a broader structural shift rather than simply an unusually expensive summer.
Rapid growth in solar capacity is increasing electricity supply during the middle of the day, placing downward pressure on prices precisely when photovoltaic generation is at its strongest. As more solar capacity enters the system, the marginal value of an additional MWh produced during these hours is declining.
At the same time, electricity demand remains relatively strong after solar generation begins to fall. The system must then rely more heavily on other sources of flexible generation to cover the evening transition.
Hydropower would normally help manage part of this shift, but weak hydrological conditions reduced hydro availability across the Balkans during August. Nuclear generation also faced operational restrictions associated with high river temperatures and low water levels.
The result was a significant scarcity premium concentrated into a relatively limited number of evening hours, creating increasingly sharp price differences within the same trading day.
This changing market structure is also reshaping renewable project economics.
For solar developers, headline annual generation is becoming a less reliable indicator of commercial performance. A growing share of solar output is being produced during hours when electricity prices are relatively low, meaning that the capture price is becoming increasingly important compared with the monthly baseload benchmark.
The trend is likely to influence decisions around plant configuration, battery storage, PPA structures and financing assumptions.
Solar remains one of the fastest-growing generation technologies in Southeast Europe, but August demonstrated that its commercial value will increasingly depend not simply on how much electricity a project produces, but when that electricity reaches the market.
Southeast Europe is gradually moving away from a market defined primarily by annual energy balances and toward one in which the hourly shape of generation and demand increasingly determines project revenues and investment returns.
