National Grid is delivering a £130 million project to refurbish and strengthen the existing overhead line network, (the high-voltage wires that transport electricity) between Lincoln and Stevenage.
National Grid’s Operations teams and Morrison Energy Services have been working at heights of up to 50m, installing 2,919 km of new overhead line conductor to replace the original, which was installed in the 1960s and is now approaching the end of its scheduled working lifespan.
Three of four north-south circuits on electricity transmission network have now been refurbished, allowing them to continue to function reliably, with completion of the fourth circuit expected in 2024.
Work on the transmission line, which runs from Cottam Power Station near Lincoln to Wymondley Substation near Stevenage, passing near Newark, Stamford, Peterborough and Hitchin, started in March 2022 and covers two project phases.
The first phase of the works from Lincoln to Peterborough was completed last year and a further 1,479km of overhead line conductor has been installed so far in this year’s second phase, which runs from Stamford to Stevenage.
Each section of work has involved in depth planning around outages - when the system operator can afford to take a particular circuit off the live network.
The final circuit, which runs from Cambridgeshire to Hertfordshire, will be replaced to complete the project in 2024.
The refurbishment of this piece of the national network enables power to continue to feed into regional electricity networks, who distribute it to homes and businesses at lower, more usable voltages. Once complete, the new line will not only strengthen the existing infrastructure from Lincolnshire through to Hertfordshire but will also ensure the network is able to continue to transport increasing volumes of renewable power.
The project forms part of National Grid’s management of the high-voltage network in England and Wales. 900 operational colleagues work 365 days a year to maintain the network, monitoring over 21,000 pylons, over 7,000 kilometres of overhead line (the same distance as London to Miami) and over 700 kilometres of underground cable.
More than £1 billion a year is invested to adapt and upgrade the transmission network, ensuring it is robust against severe weather, including storms and heatwaves and enabling the connection of more renewable power to help reduce emissions.
In addition to replacing the overhead lines, specialist teams climbed and surveyed 478 pylons along the 170km route and fitted around 80 tonnes of steel to reinforce the pylons to support the new line system. The project team have already amassed an impressive record across both phases, sharing the following highlights to date: