Bulgaria’s battery fleet has grown to more than 6.2 GW of power capacity and 19 GWh of energy capacity, according to the latest estimates. That exceeds the 3,000 MWh usable-storage target of RESTORE, which allocates EUR 603 million from the Recovery and Resilience Facility to storage in Bulgaria.
The build-out shows how public support can accelerate battery deployment. Bulgaria is now moving from a stage that rewarded construction to one in which competition and operational performance will increasingly shape project returns.
New projects add capacity
At Tvarditsa, a programme covering three battery-storage projects comprises more than 2.3 GWh of combined storage and investment of more than EUR 350 million. The first site is a five-hour battery system with 300 MWh of storage.
The European Bank for Reconstruction and Development (EBRD) is financing the Tenevo battery project alongside Raiffeisen. Tenevo has 246 MW of power capacity and 512.5 MWh of energy capacity.
Returns face growing competition
The next test for Bulgaria’s expanding fleet is whether projects can deliver attractive merchant-market returns as public support and early scarcity rents fade. Batteries will compete for the same solar-hour charging opportunities, evening price spreads and balancing services, potentially compressing revenues across the market.
As competition increases, projects with lower financing costs, longer duration, better optimisation or more advantageous grid locations are expected to outperform generic two-hour arbitrage assets. The shift puts greater weight on operational efficiency and capital discipline, rather than construction alone.
Bulgaria’s experience is expected to serve as a regional benchmark for Serbia, Romania, Croatia and the Western Balkans as they expand their storage fleets.