The level of gas held in storage is primarily a commercial decision made by companies. It is influenced by the commercial judgments of shippers and suppliers on how best to meet their supply requirements; and by the ‘cash-out’ regime under our gas market governance arrangements, which exposes gas shippers/suppliers to potentially very high cash-out charges for any daily imbalance between the quantities of gas they convey into, and remove from, the gas network.
However, there are safety monitors in place to ensure there is a minimum amount of gas in storage available over the winter, across all storage sites in GB, for the System Operator to operate the system safely at times of emergency.