The UK could store enough green hydrogen in depleted North Sea oil and gas fields to meet the country’s future electricity demands for 7 years, according to new research from the University of Durham.
Geologists and engineers from Durham Energy Institute have, in an apparent first, mapped different hydrogen storage scenarios against half-hourly data on power generation and demand, using both historical data and future simulations.
They found adding additional green hydrogen into the mix at sufficient scale would eliminate the need for gas power plants by 2040, a faster route to net zero than increasing the pace of renewables and battery storage deployment alone.
Under the scenarios mapped by the team, the hydrogen would be produced through electrolysis using excess wind and solar power, then stored underground for future use, using existing and adapted oil and gas infrastructure. This would establish ‘home grown’, large-scale, long-duration seasonal energy reserves to help the UK energy transition – with the capacity to deliver over 3500 TWh, covering the UK’s future electricity needs for 7 years.
Given the UK’s wind and solar power potential and available storage capacity, the UK has the potential to become a hydrogen exporter, helping Europe to become self-sufficient in energy, say the researchers.
Hydrogen is increasingly seen internationally as an important part of the energy mix in the move to net zero. Germany has plans to increase its hydrogen storage capacity and Denmark’s national energy strategy includes increasing hydrogen production.
The UK Government’s long-term energy strategy also supports greater use of hydrogen power plants, while acknowledging that storage capacity will need to increase substantially. At present, the focus for hydrogen storage in the UK has been primarily on salt caverns, for which there are too few for longer-term needs. Only one North Sea oil and gas field (Rough) is being developed for hydrogen storage.
The new research shows that, to deploy hydrogen storage at the scale required to realise full benefits, the UK’s depleted oil and gas fields offer a great opportunity for energy storage.
The team combined geological and engineering expertise to assess the impact that deploying hydrogen could have on the UK’s future energy mix. Rather than work with annual data, they brought together historical half-hourly data on power generation and demand, renewable deployment plans and simulations of future energy usage, accounting for the growth of electric vehicles, heat pumps, and data centres, to create a digital twin of the UK’s future energy system.
They looked at potential storage sites for hydrogen across the UK and selected the best options based on their geological characteristics, such as the nature of the capping rock and the amount of hydrogen likely to seep out during storage.
They then modelled different scenarios based on low levels of hydrogen storage (sites already under development) and higher levels (drawing on additional sites identified within depleted oil and gas fields). They compared these to a scenario that saw renewables and battery deployment increasing beyond planned targets without a corresponding increase in hydrogen production, storage and power.
They found that all scenarios helped to limit reliance on gas power plants during periods of high electricity demand and low renewable production, with gas reducing to just 1% of energy production by 2030. However, the low storage scenario saw capacity quickly saturated, which meant the full potential of both the hydrogen and renewable power deployment could not be realised. Only the high storage hydrogen scenario was able to reduce reliance on gas power to zero by 2040.
This scenario maximised the production of hydrogen when there was surplus renewable energy being generated and provided sufficient storage capacity to offer reliable backup power for long periods when required. The team calculated the total storage capacity was equal to 3659TWh of power – enough to supply the UK’s electricity needs for 7 years, based on expected usage in 2040 [see note].
Professor Stuart Jones, Co-Director of Durham Energy Institute at the University of Durham, was one of the authors of the research. He said: “Hydrogen could be a sovereign asset for the UK, a truly independent resource, that provides energy without relying on potentially unreliable imports of fuel or materials. But to achieve that, we need to look at our depleted oil and gas fields, not just salt cavern storage. The North Sea fields are a known quantity, with existing infrastructure that could be adapted to allow for deployment at scale. We need to change our thinking on this and start to plan now for the next 20 years.”
Co-author Chris Groves, Professor of Engineering at the University of Durham, said: “Hydrogen shouldn’t be seen as a standalone fuel, but as part of a flexible energy system involving renewables, electrolysis, storage and hydrogen to power plants. We will only realise the benefits of hydrogen if we scale all these elements in a coordinated way. Hydrogen’s advantage is that it can absorb the energy surplus from renewables and provide power during periods of renewable scarcity as well as to power high energy sectors such as fertiliser, steel and glass production that are hard to decarbonise.”
Although the research models the UK energy system and geology to assess the role of hydrogen, the approach can be easily adapted for other countries, say the authors. The research is published this week (mid June) in Applied Energy and involved PhD students Zongtai Zhang and Joseph Brown.
