EMEC’s onshore substation and hydrogen plant. Image Orkney Sky Cam courtesy of EMEC

The world’s first continuous green hydrogen production is planned from vanadium flow batteries combined with tidal power.

The initiative from the European Marine Energy Centre (EMEC) on Orkney will deploy an Invinity Energy Systems 1.8MWh flow battery at its tidal energy test site on the island of Eday.

This unique combination of tidal power and flow batteries will be used to power EMEC’s hydrogen production plant to demonstrate continuous hydrogen production from variable renewable generation.

The commercialisation of green hydrogen is considered an essential step toward a 100% renewable future with its potential to replace fossil fuels in the energy mix and support the decarbonisation of the industry and transport sectors.

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Invinity’s modular flow battery system will be assembled at the company’s manufacturing facility in Bathgate, West Lothian and consist of eight Invinity VS3 battery modules linked together into a single system. The project, which is being supported by the Scottish government, is expected to go live next year.

“Following a technical review looking at how to improve the efficiencies of the electrolyser we assessed that flow batteries would be the best fit for the energy system,” says Neil Kermode, Managing Director at EMEC.

“As flow batteries store electrical charge in a liquid rather than a solid, they can provide industrial quantities of power for a sustained period, can deeply discharge without damaging itself, as well as stand fully charged for extended periods without losing charge. These are all necessary qualities to integrate battery technology with the renewable power generation and hydrogen production process.”

Tidal generation is predictable yet variable, with two high and two low tides occurring each day. This is an extremely heavy cycling application, requiring up to four cycles per day, compared to solar coupled energy storage projects which typically require just one charge and discharge each day.

At EMEC’s site, the system will store electricity generated by tidal turbines during high power periods and discharge it during low power periods. This will ‘smooth’ tidal generation to create continuous, on-demand electricity to turn into hydrogen using EMEC’s 670kW hydrogen electrolyser.