A £20 millionjoint project between UK Power Networks and National Grid will compress the size of a current substation from two football fields to two tennis courts.

A new modern electricity substation near Hillfield Lane, Elstree, will be lighting thousands of homes after being installed to replace a larger existing substation and connecting new equipment to ensure the risk to power being affected is lessened.

The compressed substation will mean that existing land can now be used for other future works, improving the development around the area. The project however is set to be completed in 2021.

Geraint Hancock, a senior manager at UK Power Network, said: “The planning and implementation has been challenging as we are connecting new cables into the network while trying to ensure that none of our existing companies lose supply.

“We are taking this opportunity to upgrade the system with better technology. This investment will reinforce the network and help keep supplies secure for the next 40 years.”

Residents and businesses from Watford, Stanmore, Brimsdown, Rye House, Hendon, Borehamwood and Mill Hill are all set to benefit from the investment.

UK Power Networks keeps the lights on for more than eight million buildings across London, the South East and East of England. The company invests more than £600 million annually in maintain and improving electricity networks.