Increasing levels of distributed generation and its effect on electricity networks

The electricity industry began its transformation into an integrated network when the Central Electricity Board was established in 1926. The first high voltage regional network was built in the 1930s to enable large power stations to share capacity to meet demand. In the 1950s and 1960s a more extensive high voltage transmission system, The National Grid, was built. Since that time, the generation, transmission, distribution and supply of electricity has been designed to be a 'one-way' system. Many industry players believe that this is the most efficient way to operate an Electricity Supply Industry (ESI). However, since parts of the ESI have come out of national ownership and the industry has become more open to competition, the control of the ESI has become progressively less centralised. The trend of building generation which is not connected directly to the transmission system has arisen from market signals which make it more attractive economically to generate and supply power locally. Developments in the gas industry, the environmental agenda and the changes in the ownership within the ESI has accelerated this process in recent times. This report discusses the impact of the likely continuation of this trend on the transmission system and distribution networks. (author)