The largest battery energy‑storage system in Poland will be built. Greenvolt launches its project in Siedlce
Greenvolt Power has signed an agreement with BYD Energy Storage for the supply of technology for an energy‑storage system to be built in Siedlce. Once completed, it will be the largest battery energy‑storage facility in Poland and one of the largest of its kind in Europe.
The project will have 600 MW of power and 2.4 GWh of capacity. Construction is scheduled to begin in the third quarter of 2026, with commercial operation planned by the end of 2027.
A new leader among battery energy‑storage systems
The Siedlce storage facility is expected to play a significant role in stabilizing Poland’s power system. It will store surplus energy produced by renewable sources and feed it back into the grid during periods of increased demand. Such installations also provide balancing services and improve the overall flexibility of the system.
The project already has secured revenue from the capacity market, increasing the financial predictability of the investment. Although Greenvolt describes the project as the largest battery energy‑storage system in Poland, it is worth noting that PGE is simultaneously developing a BESS at the Żarnowiec Pumped‑Storage Power Plant. That installation will have 262 MW of power and approximately 981 MWh of capacity. This means the Siedlce project will be more than twice as large in both power and storage capacity.
BYD will supply the technology
The technology will be supplied by BYD Energy Storage, which will deliver the BYD Haohan energy‑storage system designed for large‑scale projects. The solution is engineered for power‑system applications requiring fast response and high efficiency.
– Energy storage plays a key role today in building more flexible and resilient energy systems. We are developing some of the largest BESS projects in Europe, strengthening Greenvolt’s position in this rapidly growing segment – emphasizes João Manso Neto, CEO of Greenvolt Group.
Another joint investment
The Siedlce project is the next stage of cooperation between Greenvolt and BYD in the Polish market. In 2025, the companies signed agreements for the supply of technology for energy‑storage systems in Turośń Kościelna and Nowa Wieś Ełcka. Each of those projects will have 200 MW of power and 800 MWh of capacity.
As Weronika Nowak, CEO of Greenvolt Power, notes, the Siedlce investment demonstrates both the scale of the company’s ambitions in Poland and the experience gained in delivering large‑scale energy‑storage projects.
Representatives of BYD Energy Storage add that the implementation of such a large project confirms the growing importance of battery technologies for Europe’s energy transition.
Poland accelerates its energy‑storage development
The market for large‑scale energy‑storage systems in Poland is growing rapidly. In addition to Greenvolt and PGE, similar projects are being developed by other companies and energy utilities. This is the result of the dynamic expansion of renewable energy sources and the increasing need for flexible capacity to support the national power grid.
For Greenvolt, Poland remains one of the most important markets. The company’s domestic project portfolio currently includes 238 MW of wind power, 657 MW of photovoltaics, and 2,595 MW of energy‑storage projects. These are part of the Group’s global pipeline, which exceeds 12.8 GW.
Once the Siedlce storage facility is launched, Poland will gain the largest battery energy‑storage system in the country and one of the largest in Europe. The investment is expected to enhance the security of the power system and facilitate further integration of renewable energy sources.