Underground Storage (AS) activity includes the reception, compression and underground storage as well as the depressurization and drying of gas for later delivery to the transmission network. The AS infrastructure consists of 4 natural salt caverns with volumes which vary from 330,000 m3 to 660,000 m3, approximately. The caverns are the property of REN-Armazenagem, S.A. (3 caverns) and Transgás Armazenagem, S.A. (1 cavern), which operate their respective infrastructures under the public service concession regime allowing regulated access to any Market Agent.
Also part of the AS infrastructure is a surface station provided with the necessary equipment for the safe operation of the natural gas caverns (including compressors and a filtering and drying station) and for the development of new caverns (bleaching station).
Its location near Pombal, at a central point in the pipeline network and close to the coast, facilitates not only the overall operation of the system but also the processes for building new caverns, by allowing the environmentally safe outflow of brine.
The expansion of the National Natural Gas System (SNGN) capacity through the construction of new caverns is currently under project.