Battery deployment in 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 the potential price effect a regional issue. A more stable price profile is expected, alongside occasional extreme events.
Solar generation pushes prices down around midday, while prices rise as solar output declines, 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 batteries ahead of the evening price rise and discharging during it could raise the low-price trough and reduce the evening peak.
Storage is not expected to eliminate the premium. Weather, hydro conditions, thermal outages, interconnector congestion and demand can still cause scarcity events that batteries cannot respond to. Longer-duration storage may also sustain an evening premium later into the night, after two-hour systems have emptied.
For investors, an expected narrowing of the average evening premium could affect project returns. A project commissioning in 2028 should not be valued using the 2026 evening price profile; developers are advised to model storage additions in every major neighbouring market before a project reaches mid-life.
The investment case is expected to shift, not disappear: the premium remains investable but should be treated as a declining resource. Batteries may earn less from routine daily cycling and more from selecting the most valuable days, providing balancing services and optimising portfolios.