Authors: Simon Gill and Keith Bell. The full blog post is available on the UKERC website
Development of low carbon electricity generation capacity on a level never seen before is required over the next two decades both to decrease the emissions intensity of electricity production and meet growing demand. Although a fair amount of new generation will be connected within the distribution networks, hugely increased flows on the transmission network can be expected. In this extended blog, Simon Gill and Keith Bell discuss the challenge of identifying quite how much – and where – the electricity transmission network in Britain needs to be expanded.
Strategic planning of a power system
In the late 1950s and early 1960s the Central Electricity Generation Board (CEGB) carried out a process to decide where to build new generation capacity and design the transmission network to accommodate it[1]. This led to the construction of Britain’s first 400 kV electricity transmission network. At the time, the national electricity system in England and Wales operated on a relatively limited 275 kV network developed since the Second World War to provide some interconnection between regions. However, by the 1960s it was clear that a strategic approach was needed, one that reflected the rapid growth in demand for electricity focused on the cities. At the time, the main options for how to meet that demand were from burning coal or oil, or from nuclear fission. A major focus was on the potential for economies of scale in large power stations to reduce the total cost of electricity. No longer was it efficient for regions of the country to supply their own demand from relatively local generation. Given where the demand was and where different primary sources of energy could be accessed – coal mines in the Midlands, north east England, south Wales and Kent; ports for imports of oil; or coastal sites for nuclear power stations – and the potential for moving energy via a national, high voltage electricity transmission network more cheaply than moving coal or oil via road or rail, what would be the least cost mix of power sources, their location and the cost of transmission?