Bulgaria’s battery fleet has reached more than 6.2 GW of power capacity and 19 GWh of energy capacity, according to the latest estimates. The build-out far exceeds the 3,000 MWh target set by the public support programme. The market is moving from a deployment phase that rewarded construction towards one in which competition and operating performance will shape returns.
Public support and large-scale projects
The RESTORE programme allocates 603 million euros from the Recovery and Resilience Facility for usable energy storage in Bulgaria. The country’s expansion shows how public support can accelerate battery deployment. As the fleet grows, projects face greater pressure to earn returns beyond subsidies and early scarcity rents.
At Tvarditsa, a programme covering three battery-storage projects includes more than 2.3 GWh of combined storage capacity 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 is financing the Tenevo battery project alongside Raiffeisen; Tenevo has 246 MW of power capacity and 512.5 MWh of energy capacity.
Competition puts operational performance in focus
The next test for Bulgaria’s expanding fleet 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 rises. Bulgaria is entering a phase in which operational efficiency and capital discipline, rather than construction alone, will be rewarded. The country’s experience is expected to provide a regional benchmark for Serbia, Romania, Croatia and the Western Balkans as they expand their storage fleets.