Greenvolt Starts Construction on 600 MW Battery Storage Facility in Poland
The 2.4 GWh project in Siedlce will use BYD equipment and bring the company's planned storage footprint in Poland to 1 GW.
Greenvolt Power has started construction on a 600 MW / 2.4 GWh battery energy storage system (BESS) in Siedlce, Poland, according to a report by Hacker News (https://www.ess-news.com/2026/09/25/greenvolt-begins-building-600-mw-2-4-gwh-bess-in-poland/). The company expects the facility to enter commercial operation by the end of 2027.
BYD Energy Storage will supply the project's battery hardware. The site design specifies 210 battery containers and 105 transformer containers fitted with power conversion systems to manage electricity flow between the storage cells and the grid.
Interconnection contractor P&Q will link the facility to the 400 kV transmission network operated by Polskie Sieci Elektroenergetyczne (PSE). The grid-connection scope covers construction of a new 400/110 kV substation alongside 400 kV and 110 kV cable links.
The Siedlce installation is designed to charge during periods of elevated renewable generation and discharge during peak power demand, offering grid flexibility and smoothing supply-demand balancing as Poland adds more variable wind and solar capacity. Beyond utility-scale sites, Greenvolt deploys behind-the-meter commercial and industrial systems through its Greenvolt Next subsidiary.
The new site follows a 200 MW / 800 MWh battery storage project in Turośń Kościelna that entered service in July 2026. A second 200 MW / 800 MWh installation in Ełk is scheduled to reach commercial operation in the fourth quarter of 2026. Once Siedlce is commissioned alongside those two sites, Greenvolt will operate 1 GW of battery power capacity and 4 GWh of storage capacity across Poland.
Sources
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