Bulgaria hits 500 MW of batteries, poised for rapid expansion

• Bulgaria has 500 MW/1,300 MWh of batteries online and could reach 7,000–10,000 MWh within 12–18 months, ESO says, supporting 10%–15% of daily power needs.

Bulgaria now has around 500 MW of battery energy storage in operation, equal to roughly 1,300 MWh of capacity, the head of the national grid operator said this week. The installed fleet can currently cover about 1.5% of the country’s daily electricity consumption, but far larger volumes are on the way.

In a radio interview with Bulgarian National Radio (BNR), Angelin Tsachev, chief executive of Electricity System Operator EAD (ESO), projected that Bulgaria could deploy between 7,000 MWh and 10,000 MWh of batteries over the next 12 to 18 months. If realised, that would allow storage to meet an estimated 10%–15% of daily demand by shifting energy from low-price periods to evening peaks.

Developer interest appears to support that outlook. As of the end of July, ESO had received grid-connection applications for standalone energy storage facilities totalling about 12,000 MW/34,000 MWh. More than 7,500 MW/23,000 MWh already have preliminary connection contracts, indicating a sizeable pipeline moving through early development.

The storage buildout is arriving alongside rapid growth in solar. Bulgaria’s photovoltaic capacity has reached nearly 5,500 MW after adding close to 500 MW in the first half of 2025, according to Tsachev. Batteries are expected to play a key role in making that solar output more useful to the system—soaking up midday generation that might otherwise be curtailed and discharging when demand and prices climb.

For ESO, the immediate priorities will include managing interconnection queues, ensuring adequate grid flexibility, and coordinating with developers on project timelines. For investors and offtakers, the numbers suggest a quickly maturing market where storage can support renewable integration, provide balancing services and frequency response, and improve security of supply.

While the exact pace of commissioning will depend on permitting, supply chains, and financing, the direction is clear: Bulgaria’s battery storage sector has moved from pilot phase to meaningful scale and is preparing for its next jump. If the pipeline converts as anticipated, the country’s power system could look markedly different by late 2026, with storage acting as a central tool for reliability and decarbonisation.