The largest operational Battery Energy Storage System in The Netherlands Castor is energized and ready to go
We are extremely proud to announce that SemperPower has, after the successful installation by Rolls-Royce, taken over control of its second utility-scale energy storage project Castor.
This project could not have reached its operational phase without the cooperation of our suppliers, capacity off takers as well as financiers. We truly believe that only together we can accelerate the energy transition. To pursue this goal; energy storage systems need to be realized. Therefore, the team of SemperPower is developing its concrete pipeline of 1.4GW, including the realization of our first HV-connected BESS. Stay tuned as the launch of star Antares is in sight!
Updates, stories and perspectives from the Return universe.
24-04-2025
Return starts construction Antares: mega battery energy storage in Waddinxveen, NL
A 100 MW / 200 MWh battery energy storage system in Waddinxveen, capable to power 50% of the city of The Hague, is set to go live mid 2026 and has a critical role in stabilizing the Dutch grid and accelerating the transition to renewable energy.
Return redefines energy storage with Mufasa, one of Europe’s largest battery storage systems
Return, Europe’s leading independent energy storage provider, has announced the next phase of project Mufasa—one of the largest battery energy storage systems (BESS) in Europe—developed under its Lion Storage brand.
SemperPower rebrands into Return, Europe’s number one in flexible energy
Return, the leading European independent energy storage provider, today announces a transformative update: Dutch market leader SemperPower will now operate under the Return brand.