Lekstjärnen, near Fortum’s existing hydropower plant in Trängslet, will be a focus of the study

Fortum has launched a two-year feasibility study to explore the potential for new pumped hydro storage plants in Sweden. The study will assess the commercial, technological, environmental, and regulatory conditions for establishing new storage facilities.

The study will focus on three areas in Sweden: Lekstjärnen, near Fortum’s existing hydropower plant in Trängslet, Dalarna County; and Bastvålen and Höljessjön in Värmland County. Fortum currently operates three pumped storage plants – Kymmen, Letten, and Eggsjön – across Sweden, with a total installed capacity of 89.5MW. The feasibility study will evaluate the potential for expanding pumped storage capacity.

The study aligns with Fortum’s strategy to provide reliable, clean energy and support the decarbonization of industries in the Nordic region. The company aims to contribute to the region’s energy transition and competitiveness.

Fortum emphasizes the growing importance of flexible energy solutions, such as pumped hydro storage, as the share of weather-dependent renewable energy increases. These systems play a critical role in balancing the energy grid and meeting rising electricity demand.

“Pumped hydro storage offers much-needed flexibility to the Nordic energy system and increases predictability for households and industries. Pumped hydro storage has the ability to both produce, store, and consume electricity during long periods of time and in great amounts, reaching up to thousands of megawatts. Fortum owns and operates three pumped hydro storage plants in Sweden since years and we have deep in-house expertise in the technology,” said Mikael Lemström, EVP Fortum Hydro.

Any future investment decisions will be made after completing the study. Additionally, Fortum’s associated company Kemijoki Oy is investigating the potential for pumped storage plants in northern Finland.