Gas storage is of major importance in securing supplies throughout the year. Several types of storage exist, mainly underground.
Either in aquifers: porous rocks that are naturally full of water. The gas is injected into the rock and gradually takes the place of the water.
Or in salt caverns. As the name suggests, these are sealed cavities carved out from layers of mineral salts.
Or in depleted gas deposits, meaning the gas is stored in the place of gas or oil deposits whose extraction has now come to an end.
Liquefied Natural Gas (LNG), meanwhile, is stored in outdoor cryogenic reservoirs, generally in the vicinity of methane terminals.