Summer 2026 was a good one for solar power in Croatia. Throughout the long heatwave from June to the end of August, it was the only major energy source to deliver above-average output, and its installations, with a total capacity of 1,578 MW, generated 810 GWh of electricity over the summer, 43 percent more than in the same period last year.
388 MW added
Behind the increase were plenty of sunshine and the 388 MW of new capacity added within a year. The figures come from the Croatian Renewable Energy Association (OIEH), which draws on preliminary data from the Central Bureau of Statistics (CBS) and the transmission system operator HOPS.
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In August 2026, solar installations set a new monthly record, delivering 220 GWh of electricity in that month alone. Across the three summer months, solar covered 11.87 percent of Croatia’s power consumption, and it is steadily becoming a key part of the country’s supply. Its value goes beyond the fact that sunshine is free: solar installations produce the most power in the midday heat, just when air conditioning units across Croatia are running at full capacity and demand is at its summer peak.
Cooling drives high electricity demand
This also helps PV hold down the price rises that would otherwise hit the power exchange as demand climbs. After sunset, however, prices have risen sharply, and the OIEH warns that the system lacks the flexibility and battery storage to cope. To date, Croatia has built only one large battery storage system, a 60 MW unit that is still being tested, against an estimated need of around 750 MW.
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Electricity consumption during the summer months was 6.44 percent higher than in the previous summer, mainly because people relied heavily on cooling to make the extreme heat more bearable. According to the OIEH, the heatwave lasted 45 days, with temperatures averaging 2.6°C above the long-term mean.
Hydropower collapses
The heat also hit electricity production, as river levels dropped dramatically, leaving hydropower plants with only 43 percent of their usual water volumes, the lowest figure ever recorded. As a result, they delivered just 1,014 GWh of electricity over the summer, 13.8 percent less than in the same period last year, and had to draw mainly on their reservoirs to do so.
Wind farms, meanwhile, contributed 760 GWh, around 7 percent less than a year earlier, which the OIEH puts down mainly to the lack of wind during the heatwave.
Domestic renewables cheaper than imports
Domestic power plants, including the Krško nuclear power plant in Slovenia, half of whose output goes to Croatia, delivered a total of 8.44 percent more electricity than last summer, largely thanks to higher output from fossil-fuel plants. But this increase was not enough to cover the extra demand, meaning that Croatia had to import a net 1,810 GWh of electricity over the summer, worth €249 million and equal to 26.3 percent of consumption.
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If domestic solar and wind installations had been able to fill this gap, Croatian electricity consumers would have paid just €91 million to €163 million, a saving of up to €158 million. The OIEH based these figures on production costs of €50 to €90 per MWh, and they show how directly a rapid expansion of green power would pay off for households and businesses.
Cooling requires more energy than heating
Electricity consumption in Croatia from June to September 2026 reached 6,874 GWh, 416 GWh more than in the summer of 2025. The heatwave was clearly the main driver, as the sharpest increase was recorded in August, when consumption even exceeded January, traditionally the peak month for heating. As a result, peak system loads now occur at midday in summer rather than in winter. June had already set records, with peak load reaching 3,687 MW on a single day and daily consumption of 70,348 MWh.
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Power prices follow gas
The strain on the system showed up in power exchange prices, which averaged €139.80 per MWh this summer, 53.9 percent more than last summer. The CBS recorded a steady rise, from €115.89 per MWh in June to €172.80 per MWh in September, driven mainly by higher gas prices as a result of the war in the Middle East. The summer’s highest price, €638.35 per MWh, came on the evening of 14 September, a clear sign of what the missing storage is costing the country. (su)
