Friday, 25 September 2026
Greenvolt Power has started construction of a large battery energy storage facility near Siedlce, eastern Poland, with 600 MW of power and capacity to store 2.4 GWh of electricity. Commercial operations are planned to begin by the end of 2027.
The project is being developed at Zdany in the municipality of Zbuczyn. At full output, its storage capacity would allow electricity to be supplied for approximately four hours, providing the grid with additional flexibility when electricity production and consumption are out of balance.
The development will comprise 210 battery units and 105 transformer units. BYD Energy Storage is providing the battery systems, while P&Q and ONDE are involved in the electrical and construction works required to connect and operate the facility.
The investment will be connected to Poland’s high-voltage electricity network and will be able to store surplus power during periods of greater production before supplying it back to the system when demand increases. This capability is becoming increasingly important as Poland adds more wind and solar generation, whose output varies according to weather conditions.
Siedlce follows Greenvolt’s development of two other major Polish storage facilities. Its Turośń Kościelna project provides 200 MW of power and 800 MWh of capacity, while another 200 MW/800 MWh installation is being developed at Ełk. Together with Siedlce, the three projects will represent 1 GW of power and 4 GWh of electricity storage.
Poland has become one of Greenvolt’s principal European markets for battery infrastructure. Around 2.4 GW of the company’s approximately 4.6 GW probability-adjusted European storage pipeline is located in Poland, giving the country more than half of the capacity represented by that portfolio.
Beyond the electricity market, the investment adds another large specialist development to Poland’s infrastructure pipeline. Utility-scale battery facilities require suitable land, major grid connections, substations and extensive electrical and civil engineering works, creating growing demand for sites capable of accommodating energy-intensive infrastructure.
The start of construction at Siedlce reflects the increasing role of battery storage alongside renewable generation and transmission investment in Poland. Once operational, the 2.4 GWh facility will provide additional capacity for balancing electricity supply and demand while supporting the integration of further renewable energy into the national power system.
