In a world first project, tidal power is being combined with vanadium flow batteries to produce green hydrogen.
Hydrogen will be created by using energy from a 1.8MWh flow battery from Invinity Energy Systems and tidal turbines to power a 670kW hydrogen electrolyser at the European Marine Energy Centre’s (EMEC) tidal energy test site on the island of Eday, Orkney.
The Eday site will consist of eight Invinity VS3 battery modules linked together into a single system, which will be built at the company’s manufacturing facility in West Lothian, Scotland.
The project is due to be commissioned next year.
Hydrogen is an ‘essential step’ towards a 100% renewable future, according to the companies behind the project. In particular, it can be used to decarbonise heavy industry and transport sectors, replacing fossil fuels.
Matt Harper, chief commercial officer at Invinity, said that vanadium flow batteries were “the perfect partner” for tidal power as they can continually absorb then dispatch four or more hours of continuous power, multiple times a day for decades.
While tidal generation is predictable, it is variable with two high and two low tides a day. This makes it an extremely heavy cycling application, which can be very hard on conventional lithium-ion batteries, degrading them much faster than when they are used with technologies such as solar PV.
According to Invinity— which was created following the merger of vanadium redox flow companies Avalon and redT earlier this year— vanadium flow batteries are much better suited as they are able to perform heavy-duty, stationary energy storage for high-utilisation and industrial applications.
Scotland’s energy minister, Paul Wheelhouse, said: “The demonstration of hydrogen and systems integration with renewables will be a key part of our energy transition pathways, building on the strong track record of Orkney and EMEC, in particular, in demonstrating hydrogen and integrated energy systems.”
Neil Kermode, managing director at EMEC, said the centre’s core purpose was to demonstrate technologies in “new and inspired ways” to help decarbonise the energy system.
He said: “This is the first time that a flow battery will have been coupled with tidal energy and hydrogen production, and will support the development of the innovative energy storage solution being developed in the Interreg NWE ITEG project.
“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.
“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 damage, 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.”
