Optimal planning of the transmission system in the privatised electricity industry in England and Wales

The privatisation of the electricity industry in the United Kingdom has had a significant impact on the framework in which transmission system planning is conducted. In the eight years since privatisation, the planning of the requirements for transmission capacity have become more demanding due to generation and supply competition and the developing role of the National Grid Company plc (NGC) in the continuously evolving electricity market. This has presented new challenges to system planning. To optimally plan the transmission system, NGC has reviewed its planning criteria and developed new planning techniques. This paper describes the outcome of the review and some of the key techniques developed for the design of a robust transmission system to cope with a changing and uncertain environment. These techniques include more flexible and cost effective solutions, year-round operation cost assessment tools, risk modelling and option selection tools.