2 Underground hydrogen storage
Natural gas bas been stored underground since 1916 and much of the experience is directly applicable to hydrogen. Nowadays, there are already twenty-three salt caverns being used for natural gas orstorage in the UK. In there are at least fifteen underground storage sites for natural gas, either in salt caverns or in aquifers, for a total available capacity of 110 TWh, i.e. about 30% of their current annual demand.
Over the last decades there have been several examples of underground storage of pure hydrogen or syngas:
- England, Teesside, Yorkshire: the British company ICI has stored 1 million Nm3 of nearly pure hydrogen in three salt caverns at a depth of about 400 m. The caverns have operated successfully for many years, and they are now operated by SABIC.
- France, Beynes, Ile de France: the gas company Gaz de France has stored a gas with 50-60% hydrogen in an aquifer of 330 million Nm3 capacity for nearly 20 years. No gas losses or safety problems have been recorded.
- Russia: pure hydrogen was stored underground at 90 bars for the needs of the aerospace industry.
- Germany: 62% H2 gas was stored in a salt cavern of 32,000 m3 at 80-100 bar.
- Czechoslovakia: 50% H2 was stored in an aquifer.
Furthermore, Praxair is constructing a large underground hydrogen storage facility to enable “peak shaving” of its hydrogen production. This facility, located in Texas, will utilize a salt cavern and will be the first of its kind in the industrial gases industry. Connected to the Praxair’s hydrogen pipeline network, which serves large consumers inand Louisiana, it will significantly increase the availability of hydrogen during periods of peak demand.
As a matter of fact, the main current operators of large hydrogen storage systems are actually Praxair and SABIC.