UK Delivers Europe's Largest Vanadium Flow Battery — 20.7 MWh in East Sussex

Invinity Energy Systems completed delivery and commissioning of the Copwood VFB Energy Hub in East Sussex, England on May 11, 2026 — the largest vanadium flow battery installation in Europe at 20.7 MWh across 90 individual flow battery units. The system is co-located with a 3 MW solar array and draws on the UK government's Longer Duration Energy Storage (LDES) program and National Wealth Fund financing. Unlike lithium-ion, vanadium flow batteries use an aqueous electrolyte that cannot burn or explode, making them particularly suitable for co-location with buildings and communities. The Copwood project provides 8+ hours of discharge duration — addressing the multi-day balancing gap that shorter-duration lithium-ion BESS cannot fill. The project validates vanadium flow battery technology at utility scale and represents an important diversification of grid storage chemistries beyond lithium-ion dominance. UK grid operator National Grid Electricity System Operator has cited long-duration storage as critical for meeting the government's goal of a fully decarbonised electricity system by 2035.