December 4, 2025: The European Marine Energy Centre (EMEC) said on December 3 it had successfully completed the first demonstration of tidal power, battery storage and hydrogen as a fully integrated energy system.

The trial, in Scotland’s Orkney islands. brought together three technologies — vanadium flow batteries supplied by Invinity Energy Systems, Orbital Marine Power’s O2 tidal turbine and an ITM Power 670kW electrolyzer.

Multiple energy flow scenarios were trialled, EMEC said. During high generation periods, power from the O2 was used to charge the battery system, supply electricity directly to the electrolyzer and export power to the grid.

When tidal generation was low, the battery system discharged power to keep the electrolyzer operating. Battery power was also used to support operations at EMEC’s onshore Caldale site.

This approach could help overcome future grid constraints and open up new offtake opportunities, paving the way for more resilient, responsive renewable energy systems, EMEC said.

Leonore van Velzen, operations and maintenance manager at EMEC, said the project represented the culmination of years of effort to integrate tidal energy, battery storage and hydrogen production.

Jonathan Marren, CEO at Invinity Energy Systems, said the trial showcased the strengths of the firm’s vanadium flow battery tech as a high-cycling, non-degrading and safe form of long-duration energy storage.

“EMEC have proven the suitability of vanadium flow batteries for two emerging applications in the form of green hydrogen production and tidal power firming.”