Croatia’s electricity demand reached a record summer hourly level of 3,400.5 MWh in August, exceeding both the country’s previous summer maximum and the latest winter peak. The highest point occurred at around 21:00, after most photovoltaic output had disappeared from the system. The earlier summer benchmark was 3,362.8 MWh in 2024, while the latest winter maximum stood at about 3,264.2 MWh.
The timing of the peak is described as more significant than the record value itself. Croatia has added distributed and utility-scale solar generation, which reduces daytime demand levels seen by the transmission system. After sunset, air-conditioning needs, tourism activity and household consumption remain strong.
Evening ramp follows solar drop
The shift pushes the system peak into the 20:00–22:00 period, when photovoltaic production falls rapidly. This pattern aligns with developments across Southeast Europe as solar fleets expand. In those markets, weaker midday wholesale prices are followed by steep evening demand ramps.
From the consumption side, Croatia’s demand record reflects a similar mechanism. Behind-the-meter solar can lower measured grid demand during daylight hours. When photovoltaic generation ends, demand returns to the system at the same time regional power prices typically rise.
Seasonal drivers and electricity use
Croatia consumed around 10.63 TWh of electricity between January and July, roughly 1% higher than a year earlier. Tourism remains a key seasonal factor, with summer population and commercial activity increasing along the Adriatic coast. Higher temperatures also raise air-conditioning demand.
Flexibility options for HEP and HOPS
For Croatian utility HEP and transmission operator HOPS, a larger evening peak increases the value of flexible resources. Hydropower can support system balancing because reservoir output can be shifted toward high-demand periods. Imports also provide balancing capacity but remain exposed to regional market conditions.
During dry summers, hydro availability may weaken while neighbouring markets also tighten at the same time. In that scenario, imports can become expensive. Battery energy storage systems offer a direct response to the new demand profile by charging during solar-heavy hours and discharging into the 21:00 peak.
HEP is developing storage alongside renewable projects including Korlat, and additional standalone and hybrid battery investment is expected across Croatia’s market . The economics are expected to improve as price differences between midday and evening hours widen.
Solar capacity versus peak timing
The source notes that adding more unshifted solar capacity alone is unlikely to address peaks occurring after sunset. While additional solar can reduce daytime imports and fossil generation, it contributes little to an evening demand record unless paired with storage . Croatia’s data are presented as showing why planners are increasingly focusing on flexibility rather than only total renewable megawatts.
A power system can add more solar capacity yet still register its highest demand during hours when solar output is effectively zero . Croatia’s new record indicates that its summer adequacy challenge is moving away from the hottest daylight hour toward the first hours after sunset.
