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, far exceeding the 3,000 MWh target of the country’s public support programme. The market is moving from a deployment phase, when construction was rewarded, towards one in which competition and operating performance will shape returns.
The RESTORE programme allocates 603 million euros from the Recovery and Resilience Facility to support usable energy storage in Bulgaria. The build-out shows how public support can accelerate battery deployment, while raising the question of whether projects can earn attractive merchant-market returns as subsidies and early scarcity rents fade.
At Tvarditsa, a programme covering three battery-storage projects comprises more than 2.3 GWh of combined storage and investment of more than 350 million euros. Its 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.
As the fleet expands, batteries will compete for the same solar-hour charging opportunities, evening price spreads and balancing services, potentially compressing 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 increases. The shift is towards a market that rewards 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.