With its 47 underground storage facilities at 33 locations, Germany is among the leading countries in natural gas storage. This position matters, as Germany's gas reserves for domestic production are small, and storage facilities contribute immensely to our security of supply – not just on cold days.
With the new Gas Storage Act passed by the Bundestag on 25 March 2022, the Federal Government ensures that the gas storage facilities in Germany are sufficiently filled at the beginning of winter. In order to achieve this goal, specific filling levels have been set for different time periods, which were increased again on 29 July 2022: It is envisaged that the storage facilities must be 85 percent full on 1 October, 95 percent on 1 November and still 40 percent on 1 February. In addition, a new interim target of 75 percent by 1 September is intended to speed up storage. With the Gas Storage Act, the federal government has created a regulation that helps to ensure that gas storage facilities are sufficiently filled and to curb sharp price volatility.1
Natural gas storage facilities therefore play a special role in ensuring security of supply and price stability in our country. But how do such storage facilities work? And what capacities does Germany have at its disposal?
Basically, there exist two different types of natural gas storage facility: pore storage and cavern storage. Both of these two storage types have their own advantages and geological features.3
Pore storage facilities can also be referred to as natural reservoirs. They are suitable for storing natural gas mainly due to their specific geological formations. These formations are called aquifers.3 As the name implies, pore storage facilities are located in porous rock, within which natural gas can be absorbed and stored like in a stable sponge. This is done by pumping gas at high pressure into the tiny, barely visible pores of the rock. Pore storage facilities are often depleted natural gas or crude oil reservoirs, i.e. those whose deposits have been completely exhausted. They are delimited horizontally as well as vertically and covered on top by thick layers of clay and salt, rendering them particularly suitable for natural gas storage. Below the gas-permeable rock layers, a water-bearing area marks the limits of the reservoir.4
Cavern reservoirs are large, man-made cavities, often created in underground salt domes. The salt layer acts as a gas-impermeable barrier, providing a natural seal for the reservoir. These are generally created through a specific mining operation3 involving deep drilling and controlled water injection. This process creates cavities up to 500 meters deep, providing potential storage volumes of up to 800,000 cubic meters.5 After the right equipment has been installed, gas is stored in and extracted from the resulting cavities. In comparison to pore storage, cavern storage facilities have a higher storage capacity. The reason: unlike pore storage facilities, where natural gas must first flow through porous rock to the shaft, caverns are directly connected to storage facilities at the surface.5
In all, Germany is home to 47 underground gas storage facilities at 33 locations, whose total capacity of around 23 billion cubic meters6 makes it the country with the world’s fourth-highest storage capacities, right behind the US, Ukraine and Russia. This outstanding position is not only advantageous for Germany itself; German gas storage facilities account for a good quarter of the EU's total storage capacities.7
To conclude: when it comes to gas storage, Germany is one of the world's leading nations, and contributes to security of supply and price stability even beyond its own borders.8 Its extensive reserves help to balance out daily, seasonal and weather-related fluctuations in demand. For example, on cold winter days, when heating is heavily used, 60 percent of German gas consumption can be covered by domestic gas storage facilities. The storage facilities are also a reliable source in the event of outages. Furthermore, gas storage facilities promote efficiency by reducing the need to expand gas networks. In the future, they will be of additional importance for the energy transition as a central storage solution for the power-to-gas process.8
1 Bundesregierung. Volle Gasspeicher sichern Energieversorgung: https://www.bundesregierung.de/breg-de/themen/klimaschutz/gasspeichergesetz-2029266
2 BVEG. Speicher im Untergrund: https://www.bveg.de/Erdgas/Erdgasspeicher/Speicher-im-Untergrund
3 INES. Gasspeichertypen: https://erdgasspeicher.de/erdgasspeicher/gasspeichertypen/
4 BVEG. Porenspeicher: www.bveg.de/die-branche/speicher-in-deutschland/porenspeicher/
5 BVEG. Kavernenspeicher: www.bveg.de/die-branche/speicher-in-deutschland/kavernenspeicher/
6 BDEW. Gasspeicher in Deutschland: https://www.bdew.de/service/daten-und-grafiken/gasspeicher-deutschland/
7 INES. Gasspeicherkapazitäten: https://erdgasspeicher.de/erdgasspeicher/gasspeicherkapazitaeten/
8 BVEG. Versorgungssicherheit durch Erdgasspeicher: https://www.bveg.de/die-branche/speicher-in-deutschland/versorgungssicherheit-durch-speicher/
