Sungrow and Sunotec commission 600 MWh BESS in Bulgaria for Enery

Sungrow and Bulgarian integrator Sunotec have commissioned a 150 MW/600 MWh, four-hour BESS in Nova Zagora, Bulgaria, for project owner Enery.

The facility was developed and is owned by Enery, an independent power producer with a pipeline of nearly 10 GW across 10 CEE countries. Financing came through Bulgaria’s RESTORE program – the National Infrastructure for Storage of Electricity from Renewable Sources – an EU Recovery and Resilience Facility-backed scheme covering up to 50% of construction and commissioning costs for standalone battery storage. Bulgaria’s Ministry of Energy selected 82 projects totaling 9,712 MWh under the program in April 2025, allocating BGN 1.15 billion (EUR 588 million) across successful applicants.

The system has begun commercial operations. “Through advanced optimization and active participation across power and balancing markets, the battery will provide critical flexibility to the grid while supporting the efficient integration of renewable energy,” said Petya Dimova, head of portfolio optimization at Enery.

The facility uses Sungrow’s PowerTitan 2.0 liquid-cooled technology across 120 containers, connected to the grid via a 33/110 kV substation. Sungrow says the cooling architecture reduces auxiliary power consumption by 45% compared with non-liquid-cooled alternatives and extends battery service life by two years.

The Nova Zagora project is the first phase of a broader collaboration between Sungrow and Sunotec targeting up to 800 MWh in the region, with further expansion to 1 GWh under consideration. The two companies expect to commission a total of 2.2 GWh of battery storage in Bulgaria within two months, with combined capacity reaching 3 GWh by the end of 2026. A second phase, Knizhnovik Phase 1, is a 100 MW/200 MWh hybrid BESS and solar project also developed by Enery.

Bulgaria has seen rapid BESS deployment under RESTORE, with a second program round targeting an additional 1.9 GWh announced in August 2025. Enery separately secured more than EUR 250 million in long-term portfolio financing from ČSOB in January 2026 for a 300 MW solar and 100 MW/220 MWh co-located BESS portfolio across Czechia, Slovakia, Bulgaria, and Slovenia – a distinct transaction from the RESTORE-funded Nova Zagora project.

Editor’s note: This story has been updated to reflect a revised press release issued after initial publication.