Bulgaria’s battery fleet now exceeds 6.2 GW of power capacity and has 19 GWh of energy capacity, according to the latest estimates. That is far above the 3,000 MWh target set by the country’s public support programme. The market is moving from a phase in which construction was rewarded to one where competition and operational performance will shape returns.
The RESTORE programme allocates 603 million euros from the Recovery and Resilience Facility to usable energy storage in Bulgaria. The build-out shows how public support can speed battery deployment. As capacity expands, projects increasingly need to earn returns beyond subsidies and early scarcity rents.
At Tvarditsa, a programme covering three battery-storage projects involves more than 2.3 GWh of combined storage and investment exceeding 350 million euros. The first site is a five-hour battery system with 300 MWh of storage. The European Bank for Reconstruction and Development is financing the Tenevo battery project alongside Raiffeisen; Tenevo has 246 MW of power capacity and 512.5 MWh of energy capacity.
Competition puts battery revenues to the test
The expanding fleet’s next test is whether projects can secure 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. That competition could compress revenues across the market.
Projects with lower financing costs, longer duration, better optimisation or more advantageous grid locations are expected to outperform generic two-hour arbitrage assets as competition intensifies. Bulgaria is entering a phase in which operational efficiency and capital discipline, rather than construction alone, will be rewarded.
Bulgaria’s experience is expected to provide a regional benchmark for Serbia, Romania, Croatia and the Western Balkans as they expand their storage fleets.
