Vattenfall AB, an integrated energy supplier based in Sweden, has concluded an agreement with the international energy storage company Return to operate a large-scale battery park located in Waddinxveen, in the south of the Netherlands. This project plans for a capacity of 50 megawatts (MW) with a storage capability of 100 megawatt-hours (MWh), with commissioning scheduled for the first half of 2026. The system will be connected to the high-voltage grid operated by TenneT Holding B.V.
An eight-year operation to optimise storage
As part of the eight-year contract, Vattenfall will integrate Return’s battery park into its automated trading processes. This approach aims to reduce costs related to imbalances and balancing energy within its portfolio. According to Honey Duan, Manager of External Battery Storage Systems at Vattenfall, “flexible storage systems are becoming increasingly indispensable for a stable, fossil-free and efficient energy supply.”
The park will allow Vattenfall to increase its operational flexibility in the electricity market, responding quickly to regional and temporal inefficiencies. The project aligns with Vattenfall’s broader strategy, which aims to place up to 1.5 gigawatts (GW) of large-scale battery capacity on the Northwest European electricity market in the coming years.
Expertise drawn from hydropower plant operations
Vattenfall relies on its experience operating pumped-storage power plants and optimising batteries in the Netherlands and Germany. In the Netherlands, the company is already optimising storage projects coupled with the Haringvliet and Princess Alexia wind farms. In Germany, it operates run-of-river hydroelectric plants and pumped-storage power plants with an installed capacity of approximately 2.7 GW.
Honey Duan stated that “in a volatile environment, Return’s large-scale battery provides us with valuable additional flexibility for our renewable electricity portfolio.” This integration enables Vattenfall to improve its responsiveness to market needs while optimising the efficiency of its energy trading operations.
