The facility has a power rating of 200 MW and a storage capacity of 800 MWh, allowing it to discharge at full power for approximately four hours.
From 2028, it will participate in Poland’s capacity market under a 17-year contract with a capacity obligation of 170 MW.
The system uses LFP technology, can respond to signals from the system operator within seconds and has an expected operating life of more than 20 years.
This milestone reinforces Greenvolt Power’s growing energy storage portfolio in Poland, which also includes the Elk and Siedlce projects, and its position as one of Europe’s leading BESS developers.
Greenvolt Power, part of Greenvolt Group and a leading developer of utility-scale renewable energy projects, has officially inaugurated the Turosn Koscielna Battery Energy Storage Facility, one of the largest battery energy storage systems in Poland. Located in Podlaskie Voivodeship, near Bialystok, the facility has a grid connection capacity of 200 MW and a storage capacity of 800 MWh and is connected to the national transmission grid at 110 kV.
The facility can draw electricity from the grid when it is more readily available and feed it back when demand rises, supporting the balancing of Poland’s National Power System, the provision of ancillary services and the utilisation of electricity generated by weather-dependent renewable sources. From 2028, the project will also participate in the capacity market under a 17-year contract with a capacity obligation of 170 MW, equivalent to 85% of the facility’s power rating.
Greater flexibility for Poland’s National Power System
As installed solar and wind capacity grows, so does the need for solutions that can shift electricity over time and respond quickly to changes in generation and grid load. The Turosn Koscielna facility can change its operating mode according to current system needs, enhancing the system’s flexibility and reducing the risk of curtailment of available renewable generation.
The project reflects a broader shift taking place across Poland’s energy market, where storage is emerging as one of the fastest-growing segments of the capacity mechanism. In the main auction for the 2028 delivery year, 33 electrochemical energy storage facilities secured contracts with a combined capacity obligation exceeding 1.7 GW; according to Poland’s Energy Regulatory Office, energy storage facilities collectively accounted for 15% of the contracted capacity.
'As power systems become increasingly electrified and powered by renewable energy, flexibility is becoming an indispensable element of the energy transition. Poland is one of the markets where utility-scale energy storage has a particularly important role to play, and the investment in Turosn Koscielna strengthens Greenvolt's position in one of the fastest-growing segments of the energy sector. Battery storage is one of our key growth drivers, we are actively developing projects across 13 countries, with a battery pipeline of 5 GW and milestones like this one reflect the scale of our commitment to this technology', said João Manso NetoCEO of Greenvolt Group.
196 battery modules and 49 transformer stations
The facility comprises 196 containerised battery modules and 49 containerised transformer stations. It uses lithium iron phosphate (LFP) technology and can respond to signals from the system operator within seconds, significantly faster than conventional power plants. The high durability of the cells and the efficiency of the charging and discharging processes support an expected operating life of more than 20 years.
The supporting infrastructure includes monitoring and protection systems, fire safety solutions and acoustic barriers designed to limit the facility’s impact on its surroundings. The project site covers approximately 35,000 sq m. More than 25,000 sq m, representing over 70% of the total area, is retained as biologically active land. The project underwent an environmental and social assessment in line with the standards of the International Finance Corporation (IFC), a member of the World Bank Group, and the European Bank for Reconstruction and Development (EBRD).
The standards of both institutions cover the assessment of a project’s impact on the environment and local communities, as well as measures to mitigate identified risks.
P&Q served as the general contractor, while BYD Energy Storage supplied the facility’s battery technology.
Greenvolt Power expands its energy storage portfolio
Greenvolt Power is also finalising the equivalent Elk project, in Warminsko-Mazurskie Voivodeship, with the same power rating and storage capacity as Turosn Koscielna 200 MW and 800 MWh with the commercial operation scheduled for the fourth quarter of 2026. Together, the two facilities will provide 400 MW of power and 1.6 GWh of storage capacity. The company is also developing the Siedlce project, which is planned to have a capacity of 600 MW and 2.4 GWh battery energy storage facility set to become the largest BESS project in Poland and one of the largest in Europe.
This milestone follows last month’s inauguration of the Buj Battery Energy Storage System, in Hungary — Hungary’s largest battery energy storage system currently in operation, with 99.8 MW / 288.6 MWh of capacity. Together, Buj and Turosn Koscielna illustrate the growing scale and geographic reach of Greenvolt Power’s energy storage activities across some of Europe’s most dynamic markets for utility-scale storage.
'Turosn Koscielna is particularly significant for us because it demonstrates that utility-scale energy storage is becoming a tangible part of Poland's power system. Today, we are officially presenting a completed facility connected to the grid at 110 kV, while finalising a second project of the same scale in Elk and developing the Siedlce project, with a planned power rating of 600 MW and a storage capacity of 2.4 GWh. In this way, we are steadily increasing the scale of Greenvolt Power's BESS activities in Poland', said Weronika Nowak, CEO of Greenvolt Power.
Greenvolt Power has a diversified, probability-weighted pipeline of 12.8 GW across onshore wind, solar and battery storage projects. Battery storage remains one of the company’s key growth drivers, accounting for 5 GW of the total pipeline. In Poland, as of the end of June 2026, Greenvolt Power’s portfolio comprised 2,595 MW of energy storage projects, 657 MW of solar PV projects and 238 MW of wind projects. Greenvolt expects to invest approximately €800 million in Polish Renewable Energy Assets, until year-end 2026, reinforcing its long-term commitment to accelerating the country’s energy transition and strengthening its energy security.
Source: Greenvolt Power
