Pylons – also known as electricity transmission towers – are the structural supports that have carried the UK’s network of high-voltage overhead power lines for nearly 100 years.
Today there are more than 90,000 electricity pylons across Britain, covering 4,300 route miles (7,000 kilometres).
Pylons are used to support high-voltage overhead lines – the electrical cables that transmit electricity all over the country through the electricity grid.
Electricity originally comes out of a power station at a low voltage of around 10-30 kilovolts. It then enters a transmission substation, where it passes through a ‘step-up’ transformer that turns it into high-voltage electricity – up to 400,000 volts. This ensures greater efficiency and less energy loss as it travels around the national grid.
The electricity eventually reaches another substation where it is fed through a ‘step-down’ transformer, which converts into more usable, lower-voltage electricity.
Finally, a network of local operators transports this lower-voltage electricity through their own power lines and underground cables to supply homes and businesses Pylons are usually made of steel, due to its strength. To avoid the steel conducting an electrical current from the high-voltage cables into the tower, ‘insulators’ are used. These are usually made of materials that won’t conduct an electrical current, such as porcelain or glass.As overhead lines are normally bare (uninsulated), it’s important that they’re high enough from the ground so neither human nor machine can come into contact with them.
