Poland Plans a 7 Billion-Zloty “Water Battery”

Poland plans to build its largest pumped-storage power plant above Lake Rożnów, creating what has been described as the country’s biggest “water battery.” Rożnów II is scheduled to begin operating in 2033, with the project estimated to cost about 6.8 billion to 7 billion zlotys.

The facility would be built in Łososina Dolna in the Małopolskie region, on state-owned land used by the State Forests and Tauron Ekoenergia. Its upper reservoir would sit on a mountain above the lake and hold at least about 7.7 million cubic meters of usable water.

Pumps and turbines would connect the upper reservoir with Lake Rożnów, the lower reservoir. When the electricity system has excess power, the plant would pump water uphill. When demand rises, water would flow back through turbines to generate electricity.

The planned facility would have 767 megawatts of capacity and around 3.1 gigawatt-hours of storage. Its operators expect it to stabilize Poland’s power system, absorb surplus electricity from solar and wind farms, reduce the risk of grid overloads and strengthen energy security.

The project is also expected to create hundreds of jobs over many years, while the large upper reservoir could have a flood-control role. Project documents and environmental decisions are scheduled for completion by the end of 2027, allowing construction to start the following year. Financing discussions continue.