EMEC combines tidal power, battery storage, and H₂ production in one facility

The European Energy Centre (EMEC) has demonstrated in a globally unique combination of facilities that it is possible to bundle tidal power, long-term battery storage, and hydrogen production in a coordinated energy system. The facility is operated via EMEC's research site on the island of Eday in Scotland's Orkney archipelago, where other clean energy generation techniques are also tested.

For the energy system, EMEC engineers combined three techniques that had already been tested individually and are functional. These are the 2-MW O2 tidal turbine from Orbital Marine Power, located offshore, for generating energy from tidal power; the vanadium redox batteries from Invity Energy Systems for energy storage; and the 670-kW electrolyzer from ITM Power for hydrogen production at the EMEC Caldale site on land.

Control of Energy Flows

The individual systems were interconnected in such a way that they are capable of compensating for fluctuations in the generated tidal energy. Any surplus energy is stored in the vanadium redox batteries and used to produce hydrogen when needed.

What sounds simple was a complex undertaking, as Leonore van Velzen, EMEC's Operations and Maintenance Manager, explains. EMEC researchers first had to test several energy flow scenarios to determine the optimal processes for energy generation, storage, and energy utilization and delivery.

The electricity generated by the tidal turbine charges the battery system. During periods of high electricity production, the energy is directly used to produce hydrogen. The remaining energy is fed into the local power grid. If the tidal power plant supplies less energy, then the electricity from the batteries is routed to the electrolyzer to continue producing hydrogen consistently.

According to EMEC, the test has confirmed that the system fundamentally works. The fluctuating electricity production due to tidal dependency can be effectively compensated by the battery system. However, engineers also see room for improvement in battery management and electrolyzer control. In addition to the operating scenarios, the safety of the facility was also tested, for example, how the failure of the electrolyzer affects the system and how to avoid shutting down the entire facility. Here too, implemented measures proved effective.

Building on the practical experience in hydrogen production, EMEC scientists now intend to test the production of synthetic fuels based on renewable hydrogen in the next step. The synthetic fuels could be used to supply sectors that are difficult to decarbonize, such as aviation and shipping.

The financing for the research work and the demonstration of the combined power plant's function was provided through the ITEG project, funded by Interreg North-West Europe. Further funds came from the Scottish government and the EU-funded Forward2030 project.

(olb)