Storage Can Spur UK's Hydrogen Rollout: ETI

The UK’s Energy Technologies Institute (ETI) finds that using salt caverns to store hydrogen has the potential to deliver clean, grid-scale energy supplies.

Its early July report came days before the UK’s National Infrastructure Commission said that a decisive move away from use of gas was needed in order to achieve climate change targets.

ETI told NGW that the report was completed by engineering consultancy Atkins this spring, and built on earlier ETI work that showed that hydrogen storage in salt caverns could help decarbonise UK energy supplies. It identified caverns in Cheshire, Teesside and East Yorkshire as suitable sites. 

Atkins worked alongside salt cavern natural gas storage operators SSE and Storengy UK, as well as Saudi chemicals firm Sabic which already has three caverns in Teesside to store hydrogen (H₂). The report found that a 300,000m³ fast-fill cavern in Yorkshire costs about £200m ($265mn), most of which is surface facilities, the ETI report added.

Hydrogen is produced by using electricity (be it low-carbon or not) to electrolyse water. Resultant H₂ can then be stored and then used in a variety of ways.

Since producing hydrogen uses a lot of electricity, it can be increased at night when power is cheap, the report adds; or when there is surplus wind or solar electricity at other times.

Among its conclusions, the ETI report finds that the UK has enough salt bed resource to provide tens of gigawatts equivalent onto the power grid “on a load-following basis from hydrogen turbines” used in power generation. Hydrogen could also be used to fuel trucks and trains, the ETI told NGW.

The report appears to be looking at newbuild salt-cavern storage developments, rather than conversion of existing natural gas storage units. Clearly though, existing operators in this sector would have a business advantage if hydrogen storage were promoted; this explains why Storengy UK featured the report on its Twitter feed. Such operators are also earning low returns from natural gas storage thanks to the lack of seasonality in pricing, so they are probably looking to diversify.

The Engie-owned company however is also considering the economics of alternative storage systems, such as compressing air underground using excess electricity, which is then released to power a turbine at times of peak demand.