Learnings

Outcomes

The report identified sites with development of halite at thickness suitable for salt cavern development, and developed and implemented a ranking tool to assess these sites. Sites in the Wessex and Somerset salt basins, together with sites offshore South Wales where significant halite development was proven from drilling, were assessed.  
Pipeline routings were identified and costed, and techno-economic assessments of developments at the highest ranking sites were undertaken.  
This analysis found that almost all of the identified potential development sites offer lower cost storage than a counterfactual of piping hydrogen to new (and additional) storage caverns in Cheshire, where salt cavern storage of natural gas is already underway. At a smaller scale of storage – around 1 TWh capacity – the analysis finds that development of the southern Celtic Sea site would represent the best combination of risk and cost, while at the larger scale of 4 TWh capacity, onshore development in the east of the Wessex basin - around Mappower/Winterborne Kingston – would be preferred.

Lessons Learnt

The project identified a number of areas for further work, including acquisition of seismic data over potential storage sites and potentially test drilling to confirm deposition of salt at a suitable thickness; modelling of salt cavern pressure and flow rate behaviours and more detailed pipeline routing and consenting studies will also be required to move the concept forward. Additionally, hydrogen storage is not currently covered by emerging HMG business models for hydrogen production and use, and CCS: such models will be required to provide an investment basis for the development of salt caverns.