Services Offered

Unconstrained Service

During 2008/09 LNG Storage offered an unconstrained ‘bundled’ firm service at Dynevor Arms, Glenmavis and Partington. This service consists of a space and deliverability in a set ratio known as ‘duration’. Duration is defined as space divided by deliverability.

Note: Duration does not restrict the number of days on which the service can be used.

Constrained Service


In 2008/09 LNG Storage offered a constrained firm service at Avonmouth only. Customers who book a constrained service agree to withdraw some of their gas from storage on days of very high demand, if directed by National Grid to do so. This is known as ‘constraining on’.  Customers also agree to maintain a minimum inventory of gas in store.

In recognition of these obligations, customers of the Constrained Service receive a transportation credit from National Grid, which is set at a level that reflects the saved investment in the pipeline system.  The transportation credit is subtracted from the price of the storage service.

Tankering Filling Service

A Tanker Filling Service is offered at Dynevor Arms and Glenmavis. This service is primarily for use by Scotia Gas Networks who need it to support the Scottish Independent Networks (SIN). The tanker filling service is available to transporters and other customers. In the past other customers have used tanker loads of LNG for purposes including vehicle fuel supply, gas research, fire-fighting practice and the testing of gas turbines.

The tanker filling service consists of two bookable capacities, Space (or bundled units of capacity) and Tanker Filling Slots, which can be booked independently of each other. The space only element is the same as Dynevor Arms / Glenmavis space in that it includes bundled injectability and can be filled under the normal Network Code filling rules. Customers book tanker-filling slots for a year according to the maximum number of tankers that they will need to fill in one day. The commodity charge for injecting gas into the space is the same as the standard injection commodity charge for the facility. For withdrawals there is a standard charge of £260 per tanker filled or partially filled.

Winter Injection Service

A new LNG Storage service has been offered on a trial basis for Storage Year 2008/09. This service provides the opportunity to secure up to 35 GWh of additional firm commercial injection rights into our Dynevor Arms Storage facility. These injection rights can be utilised between 01 November 2008 and 21 December 2008 and are intended to supplement the existing bundled capacity rights available through our Annual Storage Invitation.

The terms and conditions relating to this service are set out in the “National Grid LNG Storage – 2008 Winter Injection Invitation” document  that can be found at www.nationalgrid.com/uk/Gas/lngstorage/Auctions/