Since January 2022, we’ve been improving a 12km stretch of overhead power line between Cowley substation and Didcot power station in Oxfordshire.

We’re carrying out a multi-million pound refurbishment of the existing overhead power line to upgrade the network and to help meet future electricity demand in the area. 

Most of our work is happening between March and June 2022. Residents may see our engineers as they work at height to carry out the refurbishment works. This includes replacing the 400kV conductor wire, the earth wire, insulators and other fittings on the pylons.

Please note: none of our work will affect electricity supplies in the area.



Site establishment at Didcot 

January – February 

Enabling works, scaffolding, tree cutting/vegetation clearance, old birds nest removal (in consultation with an ecologist and Natural England)

March – June


June – August

Demobilisation and reinstatement



Pylon refurbishment work


The 12km (7.4 mile) pylon route, made up of 34 pylons, begins at our substation in Cowley (OX4 7QN) and goes south through the parishes of Sutton Courtenay, Culham, Nuneham Courtenay, Toot Baldon and Marsh, Garsington and Sandford on Thames to our substation at Didcot (OX11 7HH). 

There will be some local road closures on minor roads but these are on privately-owned tracks.  You may notice temporary traffic management signage for site access, for example where we’ll install scaffolding and netting in specific locations in order to carry out the work on the overhead line.  

Our works cross 12 PRoWs (footpaths and bridleways) that will close twice during the project. This is to ensure the safety of workers and the public when wire pulling takes place – an activity which usually takes around ten days.

We applied to Oxfordshire County Council for full closures and have had these approved however, the footpaths will remain open until we’re working there. Posters will be in place at key locations along the route with information about the project and our helpline telephone number and email address for enquiries.

April 2022 update

We’ve made good progress since we started work in January. Our work so far has involved preparatory works, including: site set up; vegetation clearance under the watch of our project ecology and ornithology teams; access works and laying of trackway/stone roads to reach the pylon locations; Public Rights of Way closures, with notices erected; traffic management and access works signage.

We’re now installing new conductors and fittings between the pylons and the line’s power supply is switched off while we work.

Please be assured we’ll do all we can to keep any disruption to a minimum.

We expect to complete our work by Autumn 2022.

If you have any queries about this scheme, please contact our community relations team on 
0800 073 1047 or email [email protected] They’re available daily from 7am to 7pm.

National Grid Community Grant Programme

Due to the very nature of what we do – connecting people to the energy we all use – we’re at the heart of communities and each year we make a significant charitable investment in the UK. Our Community Grant Programme is aimed at community organisations and charities in areas where we impact local people through our essential works. We fund projects run by charities and community groups that meet local community needs by providing a range of social, economic and environmental benefits. If projects meet our criteria grants of up to £10,000 can be applied for. 

Applications are reviewed on a quarterly basis. You can find more details at