We need to upgrade our existing Sundon substation near the village of Chalton and adjacent to the M1 motorway in Bedfordshire.

This is so we can safely connect new sources of low carbon energy generation and energy storage to our network, whilst also maintaining secure electricity supplies for homes and businesses in the local area and beyond.

To do this, we need to increase the number of connection bays at the existing substation. We’ll install additional equipment and expand the footprint of the existing substation at its northern boundary by approximately 138m2. Preparatory work began in mid-September 2022, with the main works beginning in early October 2022. The project is expected to complete in late summer 2024.

You can find more information about our work, including a Frequently Asked Questions (FAQ) document available to download, below.

These works will have no impact on power supplies in the local area.

Why is this work needed?

A substation is an integral part of the UK electrical transmission system. It provides a connection point for generators to put power into our network, or to connect the main network to the local distribution networks that supply homes and businesses.

We upgrade existing substations to connect additional power generation or to meet increased demand from business and domestic consumers. Substations contain electrical equipment to transform the voltage to lower or higher voltages, switching equipment to connect and disconnect circuits, and protection equipment to ensure the network operates safely and reliably.

What work will you be doing?

We need to increase the number of connection bays at the existing substation. To do this we’re installing additional equipment such as transformers, and expanding the footprint of the existing substation at its northern boundary by approximately 138m2.

We will complete the work within our normal working hours of 8am and 5pm Monday to Friday. However, we may occasionally need to work outside these hours to complete certain activities, or when circumstances such as poor weather affect our schedule. We will let you know if this is the case.

We are carrying out this work under permitted development, which means we do not require planning permission. However, we must meet environmental licences as we carry out our activity, and we’ll make sure all our work is done carefully and considerately.

How will this affect you?

Our work involves machinery such as diggers to move earth and make a suitable flat area of ground, and cranes to upgrade and install equipment. All our materials and equipment will be kept at a site compound within our current site boundary.

Vehicles and traffic

Lorries and vans will bring materials to site and will take away spoil. We have developed a traffic management plan to help reduce the impact of our vehicle movements on local people and road users.

We are working with our contractor, Gunning Transmission & Distribution Services (GTDS), to deliver this project. This means you may see their vehicles and equipment in the area and at our substation. They are acting on behalf of National Grid and we are responsible for the work, so please contact us directly if you have any questions about this project.

We will have a dedicated team at site during the day, controlling the flow of our construction traffic and ensuring that deliveries and large vehicle movements are staggered to ensure safety and to help minimise any queuing.

They will also make sure the site and surrounding area is kept tidy, using road sweepers to help keep Water End Lane, Luton Road and other nearby roads clean. Our work compound also includes space for our vehicles to safely turn around in, to make sure that roads are not obstructed.


Our work will create some noise. We will ensure that this is kept to a minimum and regularly monitored. Please be assured we will always use the construction methods that best minimise disruption to local people and the surrounding environment.


You may notice additional lighting so our teams can work safely, particularly on shorter winter days. We will turn this off when we have finished our activity each day. The lighting levels will return to how they were before after we’ve completed our construction work.

We are keeping people up to date as we progress, including our nearest neighbours. If you have any queries, you can contact us using the Freephone number and email address on this web page.

To find out more about our work, please read our Frequently Asked Questions (FAQ) document where we have responded to the most common questions we receive. You can find this in the documents section below.

National Grid Community Grant Programme

Our Community Grant Programme is aimed at organisations and charities in areas where National Grid’s work impacts on local people through our operations and site activities.

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 your project meets our criteria, you can apply for a grant of up to £10,000. To find out more, please click here.

If you have any questions about applying for a grant, you can contact us by emailing [email protected] or calling 01285 841912.

Frequently asked questions