Greenvolt Power has expanded its partnership with BYD Energy Storage by signing a new agreement to supply battery storage technology for the Siedlce Battery Energy Storage System (BESS) project in Poland.
Under the agreement, BYD Energy Storage will provide its BYD Haohan battery storage systems for the Siedlce project, which will have a planned capacity of 600 MW/2.4 GWh. Once completed, the project is expected to become the largest battery energy storage facility in Poland and one of the largest in Europe.
The agreement further strengthens the collaboration between the two companies following their earlier partnership announced in March 2025. At that time, Greenvolt Power selected BYD Energy Storage to supply battery systems for the Turośń Kościelna and Nowa Wieś Ełcka BESS projects, each with a capacity of 200 MW/800 MWh, representing a combined storage capacity of 1.6 GWh.
The Siedlce project has already secured revenues through Poland’s capacity market mechanism, providing financial certainty ahead of construction. Work on the project is scheduled to begin in the third quarter of 2026, while commercial operations are expected by the end of 2027.
Once operational, the large-scale battery storage facility will help improve grid stability, enhance system flexibility, and support the integration of increasing volumes of renewable energy into Poland’s electricity network. As solar and wind generation continue to expand across Europe, battery energy storage systems are playing a critical role in balancing electricity supply and demand while strengthening energy security.
Poland remains a strategic market for the Greenvolt Group. The company currently has a diversified development pipeline in the country comprising 238 MW of wind power, 657 MW of solar projects, and approximately 2,595 MW of battery energy storage capacity. These assets contribute to Greenvolt Group’s global renewable energy portfolio of 12.8 GW.
The latest agreement also aligns with Greenvolt Group’s broader asset rotation strategy, under which the company completed 1 GW of asset sales during 2025.
According to recent industry reports, BYD Energy Storage has emerged as one of the world’s leading battery storage providers. Together with Sungrow, the company accounted for 87% of the Latin American battery energy storage market, while Chinese companies collectively captured 76% of the global BESS integrator market.
The Siedlce project represents another major milestone in Europe’s rapidly growing energy storage sector and reinforces the increasing role of utility-scale battery systems in enabling a cleaner, more resilient, and flexible electricity grid.





