Networks – Electricity Transmission Network

Overview

Network operators are those who own and maintain the infrastructure that allows the electricity produced by generators to be transferred across the country to households/factories etc. There are two different levels of network in the UK: Transmission; and Distribution (LINK). The Transmission Network transports electricity across the entire length of the country. Large scale generation sites are directly connected to the transmission network. The electricity they produce is fed onto the network via wires supported by pylons.

Who they are

In the UK there are three network operators: Scottish Hydro Electricity Transmission (SHE); Scottish Power Transmission (SPT); and National Grid Electricity Transmission (NGET) – not to be confused with National Grid Electricity System Operator (NGESO) who are responsible for maintaining system balance and ensuring the network maintains safe frequency and voltage levels. The below map highlights the geographical area each organisation covers (Source Ofgem LINK):

The transmission lines operate at different voltages: 400kV; 275kV (Scotland also has 132kV lines as part of its transmission network, whereas the electricity lines at this voltage are considered part of the distribution network in the other parts of the country).

Recent Ofgem rulling

The network companies are essentially funded by consumers, with the costs of upgrading and maintaining the network infrastructure passed onto consumers via their electricity bill (c£281 on an average household bill in 2018/19 LINK). The companies are regulated by Ofgem, who set out ‘price control’ periods where they determine the level of revenue the three network companies can make on the capital investment that they spend on network. The next price control is due to begin in 2021, running until 2026. Ofgem recently announced that they plan to reduce the rate of return currently enjoyed by network companies by almost 50%! While this will save consumers money, it may reduce the incentive and ability of network companies to invest in the infrastructure needed to achieve the country’s net zero targets.

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