Europe's largest vanadium flow battery stores 8 MWh for over 15 hours

Spain’s Fundación Ciudad de la Energía (Ciuden) has completed operational testing of Europe’s largest vanadium redox flow battery (VRFB) at its Cubillos del Sil technology center. The 1 MW/8 MWh system uses liquid vanadium electrolytes stored in external tanks, enabling independent scaling of power and energy capacity. This design offers a lifespan exceeding 20 years and can deliver power continuously for over 15 hours, making it the longest-duration battery in Spain for experimental research. The installation also includes a 100 kW/800 kWh experimental module for advanced R&D testing. The VRFB is part of a hybrid energy testbed that integrates multiple storage technologies, including a 1 MW/5.8 MWh sodium-sulfur battery, a 600 kW/1.3 MWh lithium-ion system, and a 2.2 MW solar array, providing nearly 15 MWh of total storage capacity. The facility also incorporates hydrogen production via two electroly