Croatia’s energy regulator reported on 23 July that the number of negative-price hours on CROPEX increased sharply, rising from 196 in 2024 to 257 in 2025. The increase of approximately 31 per cent highlights the growing impact of renewable generation on the country’s electricity market and the rising frequency of periods when supply exceeds demand.
The 257 hours represented approximately 2.9 per cent of the year, equivalent to almost 10.7 full days of continuously negative pricing. These events were concentrated mainly in spring and on sunny Sundays, when electricity demand was weak, photovoltaic generation was strong and some subsidised generators continued operating under mandatory-offtake obligations or legacy support arrangements.
The commercial impact extends well beyond the hours when prices actually turn negative. Solar developers must also contend with a much larger number of periods in which prices remain positive but fall below project operating assumptions. A plant selling electricity at only €5–€20/MWh during its highest-output hours can suffer severe capture-price erosion without technically operating during a negative-price event.
Newer Croatian market-premium contracts can suspend support when prices remain negative under specified conditions, transferring more of the market signal to generators. This can improve dispatch discipline and market responsiveness, but it also increases revenue volatility for lenders and equity investors unless projects are equipped with storage, curtailment rights or more sophisticated power-offtake arrangements.
Croatia had only approximately 11 MW of battery storage capacity in March 2026, although the country’s first large-scale system entered trial operation early in the year. The regulatory framework for wider deployment is still being completed, with more meaningful additions expected from 2027.
The resulting mismatch is increasingly pronounced: negative-price exposure is already becoming structural, while utility-scale storage remains at an early stage of development. Early battery projects could benefit from relatively less crowded balancing and arbitrage markets, but they also face unresolved questions regarding network tariffs, charging status, licensing requirements and the treatment of potential double grid fees.
For solar investors, the Croatian data provides a clear warning against valuing new projects solely on the basis of annual average CROPEX prices. Capture-rate forecasts must account for at least 257 negative-price hours, additional near-zero-price periods and the possibility that continued photovoltaic expansion will deepen the midday price discount before sufficient storage capacity comes online.
The trend points to a broader shift in Croatia’s power market: as solar capacity grows faster than flexibility resources, the value of electricity will increasingly depend not only on how much power a plant produces, but also on when that power reaches the market.
