Bulgaria has rapidly expanded its battery energy storage fleet, emerging as a major European market for grid-scale storage. The country’s Ministry of Energy said in October 2026 that 6 GW of battery capacity had been connected to the electricity system in less than a year. The growth is significant because it gives the grid more ability to shift electricity from periods of high solar generation to hours when demand rises.
The expansion has been supported by European Union recovery funding and investment programmes designed to accelerate large-scale storage. Bulgaria’s Ministry of Energy reported that its National Renewable Energy Storage Infrastructure procedure, known as RESTORE, received 151 proposals by December 5, 2024. The proposals represented nearly BGN 5 billion in requested investment, while the grant budget was approximately BGN 1.154 billion. Individual projects could receive grants covering up to 50% of eligible costs per megawatt-hour of usable storage capacity.
The European Bank for Reconstruction and Development (EBRD) has also documented the scale of public support and private capital mobilisation. In its 2026 update, the bank said almost €1 billion in Recovery and Resilience Plan funding had helped mobilise several times that amount in private investment, supporting 3 GW of solar photovoltaic capacity and 15 GWh of battery storage. The EBRD worked with Bulgaria’s Ministry of Energy on grant schemes, competitive auctions and technical verification of completed projects.
A notable feature of Bulgaria’s storage expansion is its connection to the rapid growth of solar generation. Batteries can absorb surplus electricity during high-output daytime periods and discharge it later, improving the ability to use renewable power when generation falls or demand rises. The European Commission’s 2026 country report identified storage deployment as an important source of flexibility for Bulgaria’s electricity system, while warning that the timely completion of supported projects is important to capture the benefits of solar growth.
The government is also considering longer-duration storage through pumped-storage hydropower. In an October 2026 statement, the Ministry of Energy described a portfolio of eight proposed pumped-storage projects with a combined planned capacity of 70 GW, for which public-private partnerships are envisaged for most projects. This is a project portfolio under development, not operating capacity, and should not be conflated with the 6 GW of battery capacity the ministry says has already been connected.
The rapid buildout does not remove the need for grid investment or guarantee that storage will remain equally profitable as the market grows. The EBRD identifies stronger grid resilience and fewer constraints on renewable generation as expected benefits of further investment. Bulgaria’s next challenge is to integrate the expanding fleet into electricity markets and system operations so that storage delivers value beyond simply shifting solar output from one part of the day to another.