Bulgaria’s battery fleet has expanded to more than 6.2 GW of power capacity and 19 GWh of energy capacity, far exceeding the 3,000 MWh target of its public support programme. The market is moving from a deployment phase that rewarded construction to one in which competition and operational performance will shape returns.
Public funding and project build-out
The RESTORE programme allocates 603 million euros from the Recovery and Resilience Facility to usable energy storage in Bulgaria. The country’s build-out shows how public support can accelerate battery deployment. As the fleet expands, projects will need to earn returns beyond subsidies and early scarcity rents.
At Tvarditsa, a programme covering three battery-storage projects comprises more than 2.3 GWh of combined storage capacity and investment of more than 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 and revenue opportunities
The next test for Bulgaria’s expanding fleet is whether projects can secure attractive returns in merchant markets 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.
As competition grows, projects with lower financing costs, longer duration, better optimisation or more advantageous grid locations are expected to outperform generic two-hour arbitrage assets. Bulgaria is moving into a phase that rewards operational efficiency and capital discipline rather than construction alone. Its experience is expected to provide a regional benchmark for Serbia, Romania, Croatia and the Western Balkans as they expand their storage fleets.