By James Ferguson, Research Engineer – Hydrogen Systems, Offshore Renewable Energy (ORE) Catapult.
Since 2013, the Offshore Renewable Energy (ORE) Catapult has been advancing state-of-the-art technologies in offshore renewables, providing support for the industry through research, innovation, testing, and demonstration. Now, with increased ambition from the UK Government for the role of offshore renewables and hydrogen in the country’s future energy mix, we are tackling the new opportunities and challenges that arise from combining these two technologies.
Milford Haven: Energy Kingdom (MH:EK) is one project, funded by Innovate UK, that features this integrated approach. Milford Haven currently hosts an impressive range of hydrocarbon facilities, including a gas power plant, an oil refinery, and liquified natural gas terminals, which allow it to receive up to 30% of the UK’s gas imports. MH:EK, finishing in May 2022, has explored the potential of renewable hydrogen and electricity to meet the future energy needs of the region. The scope has been wide-reaching, covering world-first hardware installations, investment proposition development and planning the long-term energy transition, which has been a key focus area for the Catapult.
Milford Haven’s significance to the UK’s long-term energy transition lies in its proximity to the Celtic Sea, which stretches between Ireland, Wales, Cornwall, and France. As with the North Sea, it has the potential to host major offshore wind projects, well into tens of GW. As Wales has a limited electrical network, but significant chemical energy infrastructure, there is a possibility to use hydrogen to integrate offshore renewable energy into the region’s energy system.
ORE Catapult has been working to identify and overcome the barriers to integrated offshore wind to hydrogen projects in the Celtic Sea, a key output of which has been three deep dive investigations.
The first deep dive is into integrated wind turbine – electrolyser devices. One consideration for these devices is that it may be economically favourable to have an electrolyser with a slightly lower capacity than that of the wind turbine e.g., 80 – 90%. This raises the question of what to do with the wind power that the electrolyser cannot use. Is it best to capture this with a battery for use in standby periods, or is it easier to modify the control system of the wind turbine, or is it best to send the electricity to a dump load? There are also questions about the response time of the electrolyser and whether it can “keep up” with the wind turbine, and, if not, the capacity of energy storage required to balance the electrical system.
The second deep dive is into long-term energy planning. If there is large scale development in the Celtic Sea, we might see, for example, 40 GW of wind capacity installed. If this achieves a capacity factor of 50% and is coupled with 75% efficient electrolysis (by higher heating value), this will result in an average flow of 15 GW of hydrogen ashore. Could Milford Haven use this much hydrogen? If not, where should we send the rest? One option is to send it inland, and address pipeline infrastructure questions. An alternative is to send the hydrogen via sea to demand centres along the coast or abroad.
The third deep dive is into the safety implications of integrating offshore wind with hydrogen and landing the resulting supply into regions with large-scale energy infrastructure. We are working with safety consultants Abbot Risk Consulting to host collaborative workshops with a wide range of stakeholders. The aim is to outline the main options, identify the hazards and understand what it would take to satisfactorily reduce the risks involved.
The questions raised by an integrated wind and hydrogen energy future are numerous and substantial. The work delivered through the Milford Haven: Energy Kingdom project is helping to tackle these issues and to progress the UK towards achieving Net-Zero. Working alongside partners such as Pembroke County Council, the Port of Milford Haven, Wales and West Utilities, Arup, Riversimple, the Energy Systems Catapult and RenewableUK, ORE Catapult looks forward to continuing the drive towards this goal.
 Technoeconomic modelling of renewable hydrogen supply chains on islands with constrained grids - Ferguson  Floating wind in Wales substructure and port review (gov.wales)  Offshore Wind Outlook 2019 – Analysis - IEA  Green hydrogen cost reduction: Scaling up electrolysers to meet the 1.5C climate goal (irena.org)