Greenvolt, BYD Energy sign supply deal for 600 MW BESS in Poland

Greenvolt Power has signed an agreement with BYD Energy Storage for supply of the BYD Haohan battery system for the Siedlce BESS project in Poland, the companies said July 1. The deal also marks the start of construction.

At 600 MW/2.4 GWh, Siedlce is set to become Poland’s largest battery storage project and one of the largest in Europe. Construction is scheduled for the third quarter of 2026, with commercial operations targeted by end-2027.

The project has secured revenues through Poland’s capacity market mechanism. BYD Energy Storage will supply its Haohan utility-scale battery system for the site.

The Siedlce agreement builds on an existing BYD-Greenvolt partnership. In March 2025, the two companies signed supply deals for the Turośń Kościelna and Nowa Wieś Ełcka projects – 200 MW/800 MWh each – for a combined 1.6 GWh.

Greenvolt Power’s Poland pipeline includes 238 MW in wind, 657 MW in solar, and 2,595 MW in battery storage, within a global portfolio of 12.8 GW.