Engie Zielona Energia, a subsidiary of the international Engie Group, has finalised the acquisition of a special purpose vehicle responsible for developing a battery energy storage system with a capacity of 438 MW and a storage volume of 876 MWh in Trębaczew, Łódź province. The project is expected to reach ready-to-build status in the fourth quarter of 2026, with commercial operation scheduled for the first quarter of 2029.
Engie is a French energy corporation headquartered in Paris, whose largest shareholder as of 31 May 2026 was the French state, holding 22.64 percent of its capital. In 2025, the group generated revenues of €71.9 billion. Engie is listed on the stock exchanges in Paris and Brussels. In Poland, the group operates through Engie Polska, which has been developing renewable energy and energy storage projects in the country for years.
The acquired project in Trębaczew, in the municipality of Działoszyn, was initially developed by Mithra Energy and Futureal Investment Partners, a member of the Futureal Group. The storage facility will be directly connected to the Trębaczew electrical substation, which will facilitate power evacuation and significantly relieve the local transmission infrastructure. This is a key aspect of the investment, as locating a large-scale BESS at such a grid node enables efficient energy flow management and stabilisation of the power system.
– Expanding our portfolio of large-scale energy storage is a priority for us, as these installations are an essential foundation for a modern, renewable-based economy – said Piotr Rogóż, Country Manager of Engie Polska.
The Trębaczew project is one of the largest battery energy storage systems being developed in Poland. Its 876 MWh capacity means it will be able to store energy for approximately two hours at full power of 438 MW. This will make it possible to stabilise the grid during peak demand periods and to store surplus energy from renewable sources such as wind and solar farms. As the share of renewables in Poland’s energy mix continues to grow, such installations are becoming critical for maintaining the stability of the power system.
Engie betting on storage
The Trębaczew investment is part of Engie’s broader strategy to expand its energy storage portfolio in Poland. Earlier, Engie Zielona Energia acquired a special purpose vehicle developing a battery storage project in Tursko Wielkie in the Świętokrzyskie province, with a planned capacity of 250 MW and 1,000 MWh of storage. That project has also reached ready-to-build status, confirming that Engie is consistently implementing its investment plans in Poland.
Engie has been investing in the energy transition for years, shifting its focus from fossil fuels to renewable energy sources and modern storage technologies. Poland, as one of the fastest-growing renewable energy markets in Europe, is a key destination for Engie’s expansion. The growing share of wind and solar farms in the country’s energy mix creates a demand for flexibility, which large-scale storage facilities can provide. The Engie investment in Trębaczew is designed to meet that need.
The Trębaczew storage facility will be one of the key components of the region’s energy infrastructure. Its location near the electrical substation will enable rapid integration into the transmission system and efficient energy flow management. For Engie, this is another step in strengthening its position in the Polish market, which has long been one of the group’s priority investment destinations. Działoszyn, the municipality where the project is located, will gain a new development stimulus, and the region will benefit from greater supply stability. Completion of the project in the first quarter of 2029 means that Poland will have one of the largest facilities of its kind in Europe by the end of this decade. The earlier acquisition of the Tursko Wielkie storage facility, with 250 MW and 1,000 MWh, illustrates the scale of Engie’s commitment in Poland. Together, the two projects will deliver nearly 700 MW of new flexible capacity to Poland, significantly strengthening the power system. These investments are in line with the EU’s energy transition strategy and will support the achievement of climate goals.
Photo: Engie
