Underground compressed air
As well as aquifers and porous rock formations, large caverns in underground salt domes (which can be created by solution mining) are most suitable. Salt domes have long been used for stockpiling natural gas reserves. The salt domes lie at depths of less than 800 m and have volumes greater than 500,000 m3. Such salt domes are available in large numbers in Schleswig-Holstein and Lower Saxony.