National Grid LNG Storage (a trading division of National Grid Gas (NGG)) provides storage services from a single facility located at Avonmouth (near Bristol).
The facility liquefies natural gas by cooling it to -160 degrees centigrade and stores it in liquid form. The key feature of the facility is its location and its ability to rapidly revaporise the natural gas, and deliver it to the National Transmission System (NTS). As a result, LNG storage is able to provide a peak gas supply to shippers and supplement NGG's network capacity. In addition, LNG Storage is used as a contingency against the risk of emergencies such as system constraints, failures in supply or failures in end user interruption.
When an annual service is booked, a quantity of injectability, space and deliverability is reserved for a whole year. The cost of this capacity is invoiced in 12 monthly instalments. In addition to capacity charges, the customer pays commodity charges on the quantities of gas injected in to storage or withdrawn from storage.