Introduction: When compressors are installed, their size and configuration are based on analysis of the network at that time using current and future gas supply and demand information received from the gas market. Inevitably, as the many factors involved in that analysis change, this means that what was appropriate during installation may not be ideal many years later.

Objectives:

Establish if there is a substantial economic business case for utilising Variable Envelope Compressors on the UK Gas Transmission System.

Expected Benefits: This project will:

• Obtain the working knowledge of the operators of the two facilities that operate variable envelope centrifugal compressors on natural gas systems. This will identify the economic as well as the technical reasons for installing the technology as well as establishing first hand experience of constructing, operating and maintaining the technology.

• Use the planned construction project at either Huntingdon or Peterborough as a case study and establish what economic benefits could be gained if this technology was employed on National Grid facilities.

The project has been broken down into two high level stages. If following the meetings with the operators the viability of variable envelope compressor in terms of financial and/or technical is not proven or has realisable potential the project will be halted.