Storengy launched its 2025/2026 commercial campaign on October 14 for underground natural gas storage capacity in France. This campaign covers the gas years from 2026-27 to 2029-30. Auctions are scheduled to begin on October 22, 2025, with a commercial calendar running until September 2026.
A structured product range
Storengy’s offer is divided into three distinct categories: seasonal products Serene Atlantique and Serene Nord with a withdrawal period of 158 days; mid-range products Sediane Nord at 69 days; and fast products Saline over 26 days. Auctions will follow a public calendar, with fixed windows scheduled in January and February 2026 for Sediane and Saline offers.
Of the 90.2 terawatt-hours (TWh) of capacity available for the 2026-27 year, around 63 TWh have already been allocated, mainly through multi-year contracts. More than 27 TWh remain to be commercialised, consisting solely of mid-range and fast products.
Storage stability amid market tensions
Storengy holds nearly 75% of France’s gas storage capacity and supplies approximately 11 million consumers each winter. In the face of geopolitical disruptions across the European market, the French model has remained stable thanks to forward sales planning and medium-term visibility.
For the following three gas years, Storengy plans to market close to 100 TWh of capacity, mainly through seasonal products. This approach is enabled by the flexibilities introduced by deliberation no. 2025-220 of September 24, 2025, issued by the French Energy Regulatory Commission (Commission de régulation de l’énergie – CRE).
Digitalisation and operational services
The myStorengy portal now centralises auction management, nominations, and real-time stock monitoring. The offering includes demand-driven services such as short-term increases in injection or withdrawal capacity, secured financing solutions, and simplified access to the secondary market.
In 2025, the company reported a customer satisfaction score of 8.8 out of 10, up from 8.6 the previous year, based on a survey conducted in spring. This improvement is attributed to ongoing digital development and streamlined user processes.
Targeted investments in infrastructure
Storengy has allocated an investment budget of EUR225mn ($238mn) for 2025. This includes EUR13mn ($13.8mn) dedicated to reducing emissions from its infrastructure, in line with adapting installations to new gas market requirements.
The Gournay-sur-Aronde site in the Oise region is undergoing a conversion from B-gas to H-gas, scheduled from April 2027. A new electrocompressor has been installed to improve energy efficiency while reducing emissions. This technical upgrade enhances its integration into the national network and supports long-term service continuity.
