Battery storage in Southeast Europe is moving from pilot deployments toward core market infrastructure, with Bulgaria and Romania highlighted as early indicators of how flexibility assets may affect regional power systems. Market exposure to price volatility, congestion risks and periods of negative pricing is increasing the role of batteries in balancing services, ancillary markets and renewable integration.
Bulgaria targets about 3 GWh of installed capacity by 2026
Bulgaria is described as the most advanced example of the transition. The country is on track to reach around 3 GWh of installed battery storage capacity by 2026, supported by a pipeline of utility-scale projects.
Among the developments is Knizhnovik Phase 1, a 100 MW / 200 MWh hybrid battery and solar project developed by Enery. Another project mentioned is Nova Zagora, one of the first large stand-alone BESS installations aligned with national grid requirements. These projects are presented as part of a shift toward grid-connected storage at scale.
Further momentum is linked to larger hybrid and stand-alone facilities. A major project associated with Sungrow and Sunotec is cited at 150 MW / 600 MWh. Regional clustering in Nova Zagora is expected to expand toward 800 MWh, with potential growth up to 1 GWh under consideration.
The deployment pace in Bulgaria is also quantified, with more than 2.2 GWh expected to come online within a two-month window. Additional activity includes a Sermatec installation in Bulgaria with 10 MW / 31 MWh. The system is described as fully integrated for participation in both energy trading and ancillary service markets.
Romania adds storage to existing solar through a retrofit approach
Romania’s storage build-out is described as more incremental, while still positioned as strategically important. PPC Renewables Romania is deploying a battery system at the Colibași photovoltaic park in Giurgiu County. The project capacity is listed as 4.47 MW / 8.94 MWh.
The financing structure cited combines EU Modernisation Fund support with private capital. The battery addition is described as a retrofit to existing solar assets, intended to improve dispatchability and strengthen project economics. This pathway is presented alongside Bulgaria’s utility-scale build-out.
Batteries expand across day-ahead, intraday and balancing markets
The market signal across Southeast Europe is described as increasingly clear regarding the role of batteries. Battery storage is characterised as moving beyond a supporting technology toward a structural component of the regional power system. Developers, utilities and traders that can optimise storage across day-ahead, intraday and balancing markets are identified as gaining an advantage.
The next phase of renewable expansion is linked to shifting priorities toward controlling system flexibility rather than focusing only on securing generation assets. Batteries are referenced as supporting balancing services, ancillary markets and renewable integration amid price volatility, congestion risks and negative pricing periods.
