European Marine Energy Centre (EMEC), Orkney

The commercialisation of green hydrogen production is another essential step towards a 100% renewable future. Green hydrogen is created and consumed without carbon emissions and could replace fossil fuels in the energy mix, supporting the decarbonisation of both heavy industry and transport sectors.

EMEC’s wave and tidal energy facility is designed to demonstrate the benefits of these technologies in new and inspired ways that help to decarbonise energy systems. This particular project, part of the Interreg North-West Europe funded project ITEG and supported with funding from the Scottish Government via Highlands and Islands Enterprise as well as the EU-funded FORWARD2030 project, was designed to explore how tidal and hydrogen production could be combined as a solution in coastal areas to overcome grid constraints and assist the development of e-fuel production.

During development of the project, EMEC had identified that in order to improve the efficiencies of the electrolyser and ensure continuous production of green hydrogen, an energy storage system would be required that could cope with the high-cycling requirements of the predictable but variable tidal generation.

EMEC chose Invinity’s modular vanadium flow battery to sit at the heart of the entire system in between the tidal generator and the electrolyser. Due to its lack of degradation, best in class safety characteristics and high-cycling capabilities, this battery enables the maximum onsite use of the tidal generator to provide continuous 24/7 power baseload power to the electrolyser.

The battery was delivered in stages via road and ferry to the island located off the north coast of Scotland. Housed inside a simple building, the battery was swiftly installed and energised without the need for HVAC or other fire suppression systems, given the lack of fire risk associated with Invinity’s VFBs.

In 2025, EMEC operated the entire system successfully and seamlessly, smoothing out the cyclicality of tidal energy to provide on-demand electricity to power the electrolyser for hydrogen production and maximise its efficiency. More specifically, the vanadium flow battery was charged by excess tidal energy and discharged that power to the electrolyser when tidal generation was low.

This is the first time globally that tidal power, vanadium flow battery storage and hydrogen production technologies have been integrated into a single system, underlining how a predictable yet variable renewable energy source can be harnessed by a storage technology that can operate with multiple daily charge cycles to realise the system’s full potential. This novel system paves the way for more resilient, responsive renewable energy systems that can be deployed globally at any scale according to site needs.