The European Marine Energy Center (EMEC) has completed demonstration work on a combined battery storage, tidal energy and hydrogen production plant in Orkney, Scotland.
The EMEC described the work as a “world first” integration of the three technologies; during periods of high generation, the energy generated by the tidal turbine charged the battery, powered the hydrogen electrolyser and exported power to the grid; during periods of low generation, the battery discharged current to the electrolyzer to keep it running.
The successful tests follow a recommendation from EMEC and Offshore Renewable Energy (ORE) Catapult, with as many as 30 tidal current projects found around the Scottish coast that can supply power to local users without having to connect to the national grid. The addition of batteries to tidal energy projects further improves their resilience and flexibility, making them a more viable option for providing reliable power without the need for a grid connection.
In fact, the EMEC said that this combination of technologies has “effectively smoothed out the cyclical nature of tidal energy” by ensuring consistent power supply despite differences in generation conditions. The technology was provided by Orbital Power, which supplied its O2 tidal turbine; Invinity Energy Systems, which supplied vanadium flow batteries; and ITM Power, which supplied the electrolyser.
“This unique project showcases the strengths of our vanadium flow battery technology as a highly cycling, non-degrading and fundamentally safe form of long-term energy storage,” said Jonathan Marren, CEO of Invinity. “With this exciting demonstration, EMEC has proven the suitability of vanadium flow batteries for two emerging applications in green hydrogen production and tidal energy.
The news follows the advancement of Invinity’s 20.7 MWh vanadium flow batterythe largest in Britain, which the company expects to start commercially operating next year, alongside a solar PV project in the south east of England.
‘React quickly’ to test scenarios
The project has received support and funding from a number of organisations, including the €310m (£270.69m) Interreg North-West Europe initiative and the €26.7m FORWARD2030 programme, both of which receive funding from the EU.
The EMEC also completed testing work for “all planned operational scenarios”, including successfully responding to an electrolyser shutdown “within seconds” to prevent a complete shutdown. The testing also identified potential areas for improvement, including better battery management and improved electrolyser controls.
“Bringing together three innovative technologies was a complex challenge, but achieving this milestone has provided valuable insights,” says EMEC operations and maintenance manager Leonore Van Velzen.
“Executing all planned scenarios, responding quickly to an electrolyser trip and identifying opportunities for greater automation have given us a clear roadmap for optimizing future systems. The trial also highlights an alternative path for tidal energy in scenarios where the export capacity of the electricity grid is limited, a likely feature in the future as we transition to a fully renewable energy system.”
