Securing energy markets and supply
The storage of natural gas is a strategic issue: in fact it ensures energy market security and supply securement. In accordance with European legislation on energy markets, all of the Group’s storage capacities are made available to all of the suppliers in the market.
Since 2008, ENGIE’s underground storage activities have been run by Storengy, 100% owned subsidiary of the Group. ENGIE is the No. 1 seller of storage capacity in Europe, and owns the second largest storage capacity, with 14 underground storage facilities in France and further storage capacity in the United Kingdom and Germany.
The Group is also engaged in storage activities in Romania, Slovakia, and the Czech Republic through partnerships or stakes owned.
How is natural gas stored?
Before storage, natural gas is compressed either:
in porous rock formations that are naturally waterlogged; in which case, it is referred to as “aquifer reservoir” storage,
in caverns leached out of salt layers; this is called “salt formation” storage,
in former gas deposits or wells no longer in use; in this case it is known as “depleted gas reservoir” storage.
These underground reservoirs are filled in summer when gas consumption is lower, to be able to cope with periods of high consumption in winter.
A sustained increase in storage capacity between 2013 – 2020
With its acknowledged expert competencies related to storage, the Group is currently setting up some major projects. New storage capacity is being developed in Germany (in salt formations and depleted reservoirs) and in the UK (a storage capacity of 400 million m³ is scheduled to be incrementally brought into operation between 2013 – 2020).