Return Reaches Financial Close on €400M, 800 MWh Sirius Battery Project in Netherlands

Dutch developer Return reached financial close on September 1, 2026 for its 200 MW/800 MWh (4-hour) Sirius battery storage project in Winschoten, Groningen, backed by a €400 million (~$463 million) financing package from NatWest, Deutsche Bank, ABN AMRO, Rabobank, and NG. The close was underpinned by a new long-term fixed-price toll agreement with utility Vattenfall — Return and Vattenfall's second such deal after the 100 MW/200 MWh Antares project in Waddinxveen (April 2025), and one of the largest fixed-price BESS tolls signed in the Netherlands to date. The project connects to grid operator TenneT under a time-dependent transport-rights arrangement and targets commercial operations in Q4 2027.