With the growth of renewables a clean, dispatchable power source will be required in the 2030s. One scheme for providing this involves storing large quantities of H2 in salt caverns, and to use the inventory to produce power or heat during peak hours. Although H2 is stored already in caverns in the UK, there has been little work on the effect of rapid repetitive cycling on cavern integrity.The suitability of UK salt caverns for use in storing H2 in rapid cycle mode is examined, based on detailed geotechnical analysis of saltfields in Yorkshire, Teesside and Cheshire. A detailed analysis is carried out by Atkins on a Cheshire cavern, using a combination of superimposed seasonal and daily demand patterns .The limitations of today’s market offering for firing H2 in gas turbines is described. Outline costing for schemes taking H2from salt caverns and producing power are presented in the main report.These are the appendices to the main report:A: Baseline Information and AssumptionsB: Power GenerationC: Surface Plant Process DesignD: Cavern StorageE: Economic ViabilityF: Low Carbon CaseG: Cheshire Case Study: Cavern Cyclic Loading Impact