Bulgaria is moving from discussing energy storage potential toward building a commercial battery storage market. A key development took place in Burgas, where Solarpro Technology, working with CATL, connected a 602 MWh battery storage facility to the electricity grid. The project increases Bulgaria’s total storage capacity by about 10% and is described as among the largest battery installations in Eastern Europe. It is intended to provide balancing services and help manage fluctuations between electricity supply and demand.
Bulgaria’s role in the Southeast European electricity market is part of the context for new storage investments. In the second half of June, IBEX Bulgaria averaged €99.72/MWh. Prices were higher in northern regional markets, with Hungary at €149.01/MWh and Romania at €146.80/MWh. The spread between these markets supports opportunities for storage assets through intraday price differentials, balancing services and cross-border optimisation.
New battery projects expand operating portfolios
Corporate activity in Bulgaria’s storage sector has also increased. GEN-I Invest acquired three battery projects in Belovo, Momchilgrad and Parvomay, with a combined capacity of 30 MW / 76 MWh. The acquisition raised GEN-I’s owned storage portfolio to 42 MW / 100 MWh, including its existing Slovenian battery facility. The company expects its managed battery capacity in Bulgaria and Romania to reach around 800 MW during the year and is targeting additional acquisitions of roughly 100 MW.
A separate commissioning was reported by Energo-Pro. The company commissioned a 10.75 MW / 24.31 MWh battery storage system in Gorna Oryahovitsa. The project was valued at €4.23 million and received partial support through Bulgaria’s National Recovery and Resilience Plan. It is designed to charge during lower-demand periods and discharge during peak consumption hours or when balancing services are required.
The Energo-Pro system is expected to operate for at least 10 years. It is also expected to complete more than 7,000 charging and discharging cycles. The commissioning adds another operational reference point for battery participation in grid needs tied to demand patterns and balancing requirements.
Policy changes target long-term contracting and storage deployment
Bulgaria’s regulatory framework is also being updated to support further expansion of batteries. The Energy Ministry is preparing amendments to the Renewable Energy Sources Law aimed at encouraging long-term power purchase agreements. The same amendments are intended to support faster renewable energy development, distributed generation and wider deployment of energy storage. For investors, the changes are linked to requirements beyond equipment, including grid-access procedures, market participation rules, balancing mechanisms and predictable revenue structures.
Batteries align with generation shifts and market participation models
The growth of storage is connected to changes in Bulgaria’s generation mix. Nuclear power remains described as the backbone of the system, while solar capacity is expanding quickly. At the same time, coal-fired generation faces increasing pressure from emissions costs, ageing infrastructure and changing market conditions. As solar output rises, flexible resources are needed to absorb midday renewable surpluses and supply electricity during evening demand peaks.
Batteries are positioned as one of the fastest solutions for that flexibility requirement. For investors, three commercial opportunity areas are highlighted for Bulgaria’s storage market: merchant arbitrage, participation in balancing and ancillary service markets, and co-located storage with solar and hybrid projects. Merchant arbitrage involves buying electricity during low-price periods and selling during high-price hours. Balancing participation covers providing flexibility to the transmission system.
The co-location model is described as improving project economics by reducing exposure to curtailment, price cannibalisation and market volatility associated with standalone operation. The strongest projects are expected to combine all three revenue models rather than depend on a single mechanism. This approach aligns with how revenues can be structured around multiple income streams.
Southeast Europe interconnector context shapes value capture
Bulgaria’s expanding battery sector is also described as strategically relevant for the wider Southeast European electricity market. The country sits between lower-cost southern Balkan markets and higher-value northern and western demand centres. Storage can therefore be used to manage regional price differences, interconnector constraints and renewable generation volatility across the area.
The developments point toward a merchant flexibility market structure in which storage plays a central role in electricity trading, grid stability and long-term investment planning.
