Battery deployment across Southeast Europe is expected to narrow the evening price premium that has created a commercial opportunity for storage. Bulgaria’s fleet is estimated at more than 19 GWh, making its potential effect on prices a regional issue, with a more stable price profile expected alongside occasional extreme events.
Solar output pushes prices down around midday, but they rise as generation falls, demand stays high and flexible generation becomes scarce. In Serbia during August, prices were around EUR 66/MWh at midday and averaged roughly EUR 244/MWh around hour 20. Charging ahead of the evening demand ramp and discharging during it could raise the low-price trough and reduce the evening peak.
Battery storage is not expected to eliminate the premium, as weather, hydro conditions, thermal outages, interconnector congestion and demand can still cause scarcity events beyond batteries’ ability to respond. Longer-duration storage could also keep an evening premium in place later into the night, after two-hour systems have emptied.
For investors, a narrower average evening premium could alter project returns. A project commissioned in 2028 should not be valued against the 2026 evening price curve, and developers are advised to include storage additions in every major neighbouring market in their modelling before a project reaches mid-life.
The investment case is expected to shift, not disappear: the premium remains investable but should be regarded as a declining resource. Batteries may earn less through routine daily cycling and more by selecting the most valuable days, providing balancing services and optimising portfolios.