Storage takes place in different types of underground storage facilities: In cavern storage facilities, which are constructed in salt formations, in aquifers and in depleted oil and gas deposits. All of them are safe storage facilities with low space consumption, which have moderate costs compared to above-ground storage tanks. Large amounts of energy can be stored in them, e.g. in the form of natural gas, petroleum, gas and oil products, compressed air or hydrogen.

As storage tanks they compensate for fluctuations in demand, help to keep energy prices stable and serve as a reserve for our secure energy supply - today and in the future. Underground storage facilities are becoming increasingly important as compressed air and hydrogen storage facilities for the energy transition.