Croatia set a new transmission-system electricity demand record on 11 August, with average load reaching 3,400 MW between 20:00 and 21:00, illustrating the growing importance of the summer evening ramp in a system increasingly influenced by distributed solar generation.
Transmission system operator HOPS recorded 64 GWh of electricity withdrawn from the transmission network over the full day.
Actual nationwide consumption was higher because the transmission figures exclude electricity generated and consumed directly behind the meter, particularly from household and commercial solar installations.
Croatia now has around 600 MW of residential rooftop solar, according to the report. That capacity increasingly suppresses visible network demand during daylight hours, creating a growing difference between underlying electricity consumption and demand measured directly at transmission level.
The result is a more pronounced daily load shape. Solar generation reduces the amount of centrally supplied electricity required during sunny hours, but that output falls rapidly towards evening just as air-conditioning and residential demand can remain elevated.
Croatia’s new system record occurring between 20:00 and 21:00 is therefore significant. It demonstrates that the highest stress on the transmission system can increasingly occur after solar production has declined rather than during the hottest part of the afternoon.
The Croatian record contrasts with neighbouring Slovenia, where the highest hourly transmission load of 2,300 MW was recorded between 08:00 and 09:00 on 8 January 2026 during an exceptionally cold period.
The two markets consequently face different seasonal demand extremes. Slovenia’s record reflects winter heating and cold-weather conditions, while Croatia’s was established during the summer holiday and cooling-demand season.
The difference also has trading implications. Croatia’s combination of tourism-driven summer consumption and a growing distributed solar base can produce relatively comfortable daytime balances followed by materially tighter evening conditions. Those intraday changes become increasingly relevant for cross-border flows with Slovenia, Hungary, Bosnia and Herzegovina and Serbia.
The 3.4 GW record also illustrates why installed behind-the-meter solar cannot be assessed solely by its contribution to annual energy production. As rooftop penetration rises, its influence on network demand, peak timing and flexibility requirements becomes just as important as the amount of electricity produced.
