Greenvolt Power has started construction of a 600 MW/2.4 GWh BESS in Siedlce, Poland. It said it expects to begin commercial operations by the end of 2027.

BYD Energy Storage will supply the battery technology. The project will use 210 battery containers and 105 transformer containers equipped with power conversion systems to transfer electricity between the batteries and the grid.

P&Q will connect the BESS to the transmission network operated by Polskie Sieci Elektroenergetyczne (PSE) at 400 kV. The connection works include a new 400/110 kV substation and 400 kV and 110 kV cable links.

The facility will charge during periods of high renewable generation and discharge when electricity demand rises. Greenvolt expects the project to improve system flexibility, support the integration of wind and solar power, and help balance supply and demand.

Greenvolt has expanded its battery storage portfolio across Europe, including behind-the-meter systems for commercial and industrial customers through its Greenvolt Next subsidiary.

Greenvolt Power already operates a 200 MW/800 MWh battery storage project at Turośń Kościelna in Poland, which entered operation in July 2026.

A second 200 MW/800 MWh project at Ełk is scheduled to enter commercial operation in the fourth quarter of 2026.

Once Siedlce, Turośń Kościelna and Ełk are operating, Greenvolt will have 1 GW of battery power capacity and 4 GWh of storage capacity in Poland.

The portfolio will give the company a larger role in providing flexibility as Poland expands variable renewable generation.

From pv magazine France