Across Southeast Europe in Week 42, wind and solar electricity generation rose 30.1% to 3,597.48 GWh, but weekly wholesale power prices increased in every market covered. Wind generation climbed 86.6% to 2,133.35 GWh, while solar output fell 9.7% to 1,464.13 GWh. Figures are courtesy of Virtu.Energy market data.
Serbia’s weekly electricity price rose 28.53%, followed by increases of 12.60% in Bulgaria, 11% in Croatia, 9.72% in Romania, 8.99% in Hungary and 6.70% in Greece. The price gains came despite the sharp rise in regional variable renewable production. Higher output across the region did not mean that each market received more renewable electricity.
Türkiye accounted for a large share of the regional increase, and Italy also added substantial production. Romania and Greece recorded strong wind gains, while Bulgaria’s combined wind and solar generation fell 21.5%. Hungary also reported weaker variable renewable output. The regional total therefore concealed substantial differences between countries.
Wholesale prices depend on supply and demand in individual marginal hours, not just average weekly renewable production. A system may have ample wind generation overnight but still face costly evening peaks when renewable output falls as consumption rises. The timing of production matters alongside the amount generated.
Cross-border flows and system flexibility
Transmission constraints can keep wholesale prices apart even as regional renewable output grows. Lower-cost electricity from a surplus bidding zone may not be able to reach a market facing a deficit. Week 42 also showed different outcomes for countries with rising renewable generation.
Greece recorded stronger renewable production, larger electricity exports and comparatively low prices. Serbia increased its wind and solar generation but moved substantially further into net imports as demand rose and hydropower output declined. These differences illustrate why higher regional production alone did not prevent price increases across the markets covered.
The investment debate in Southeast Europe is consequently moving beyond installed renewable capacity to storage, transmission, demand response and portfolio management. Batteries can hold surplus wind and solar electricity from lower-priced periods for release during evening peaks, while cross-border interconnectors can transfer surpluses between markets. Flexible hydro and thermal plants can offset changes in renewable output, and industrial demand response can ease system pressure during expensive hours. The issue is the ability to move, store and reshape renewable electricity for the hours and locations where it has the highest value.
Hourly generation and PPA costs
For renewable developers, future project revenues will increasingly depend on the hourly generation profile rather than annual megawatt-hours alone. Two solar projects with identical annual output can have different economics if one is in a congested market with midday price compression and the other has access to storage or stronger cross-border capacity. Installed capacity by itself does not capture that difference.
The distinction also applies to corporate power purchase agreements (PPAs). Buyers seeking predictable energy costs need to distinguish between buying annual renewable volumes and securing electricity in the hours when their facilities consume it. Week 42 brought substantially more wind and solar generation to Southeast Europe, yet several markets became significantly more expensive. Courtesy of Virtu.Energy.