Salt caverns are the only proven technology able to store hydrogen safely and economically at the massive scale required for the energy transition. Storelectric has earmarked 12 salt caverns at Tees Energy Park in Teesside, offering approximately 125 GWh of capacity, for hydrogen storage.

Salt caverns are formed by solution mining. Water is injected into a salt formation to dissolve a cavity, and the resulting brine is extracted, leaving a sealed void with the low permeability needed to contain gas without leakage. Cavern-based gas storage has been widely used since the 1950s, and cavern storage now safely holds around a third of Europe's natural gas stocks.

Tees Energy Park is an approximately 600-acre site with 110 pre-existing salt caverns owned by Storelectric. Solution mining remains available as an option to expand capacity beyond the existing 110 caverns.

The structural performance of salt caverns is proven over decades. Air storage caverns, tested at 27 years old, show close to the same structural integrity as on day one, supporting a multi-decade operating life.

Storelectric's pressure control system stores hydrogen at the same pressure it is produced at, avoiding the extra compression energy that most storage technologies require, and cutting costly parasitic losses.

Salt cavern storage is the only technology able to meet hydrogen demand at gigawatt-hour to terawatt-hour scale.