Croatia’s power market had about 220 hours of negative electricity prices during the first half of 2026 as renewable generation expanded. The combination is sharpening the commercial case for batteries, which can help absorb surplus power and shift it across time.
AdriaFlex is seeking partners for standalone battery projects in Croatia. Its portfolio comprises 170 MW across three sites, alongside an additional early-stage battery energy storage system pipeline of around 200 MW. The developer is targeting ready-to-build status in the fourth quarter of 2028.
Wind and solar account for 44% of Croatia’s installed capacity. Negative prices indicate that generation is arriving faster than the power system can shift or absorb it, creating periods when batteries can charge at low prices.
Separately, wpd plans to repower Croatia’s Trtar Krtolin wind farm, raising its capacity from 11.2 MW to as much as 30 MW with fewer, larger turbines. Annual output is expected to rise from around 30 GWh to about 55 GWh, with a 10 MW battery also planned.
The repowering and battery addition would turn the wind farm from a generation-only asset into a hybrid project intended to focus on market value as well as output. Croatia is an early Southeast European example of storage economics shifting from reliance on policy support toward merchant optimisation.
The commercial test for batteries will be how quickly they can earn revenue from intraday spreads, charging during negative-price periods, balancing and congestion before competition compresses returns. Storage revenues are expected to depend increasingly on combining arbitrage, balancing and grid services rather than relying on a single contracted income stream.
