We propose a series of works to build and operate three new substations – one near Brinsworth, another near Chesterfield and a third in High Marnham – to allow us to safely carry more energy between the North of England and the Midlands. 

The proposed substations would also enable us to upgrade the existing Brinsworth to Chesterfield and Chesterfield to High Marnham overhead electricity lines and connect future electricity transmission network projects as part of The Great Grid Upgrade.

High Marnham

We propose to build and operate a new 400 kV substation extending to the west of our existing site in High Marnham, near Normanton on Trent in Nottinghamshire. We’d remove some of the existing equipment and replace it with new infrastructure.

We expect an air insulated switchgear (AIS) 400kV substation with associated infrastructure as the site has sufficient space to accommodate an AIS – which requires more space than a gas insulated switchgear (GIS) substation. 

Based on what we know to date, we’re proposing it will be an Air Insulated Switchgear (AIS) 400kV substation with associated infrastructure as the site has sufficient space to accommodate an AIS – which requires more space than a Gas Insulated Switchgear (GIS) substation. 

The new substation would be within a compound approximately 490 metres x 220 metres – the size of around 16 football pitches –and includes supergrid transformers, which are used to increase or decrease the voltage of electricity between different circuits. The substation would include approximately 20 bays, network stability equipment, standard substation plant and control infrastructure.

The highest structures within the substation compound would be the overhead line gantries, which are bridge-like structures with platforms used to support equipment and cabling, at approximately 12 metres high. There would be ten overhead line gantries. The proposed new substation site has the potential for future expansion, if required.   

High Marnham substation


High Marnham substation

We also propose a temporary diversion of the existing Chesterfield to High Marnham, High Marnham to Stoke Bardolph and High Marnham to West Burton overhead electricity lines, with temporary pylons during construction. We expect these temporary diversions would be in place for up to three years. We’ll include details when we submit our planning application.

To turn the overhead line into the new substation and remove 26 pylons, we'd need to build nine new pylons—seven to the south and two to the north. 

High Marnham Bridge

Learn more 

Submit your feedback

We value your input as we develop our plans – feedback from local communities and stakeholders will play an important part and help shape our plans ahead of the planning applications.

To provide feedback on our High Marnham proposals you can: 

  • Complete an online feedback form

  • Email your comments to: [email protected]

  • Call us on freephone 0800 073 1047 between 9am and 5.30pm

  • Post your written responses or printed feedback form to: FREEPOST National Grid Projects (JBP) (no stamp or additional address information required)

If you’d like help submitting your feedback or require a feedback form in another format, please contact our Community Relations Team.

We must receive your comments by 11.59pm on Monday 20 May 2024.

Consultation events

Join us at one of our consultation events to find out more about our proposals – members of the project team will be available to answer questions:

High Marnham face-to face events:





High Marnham

2pm-7pm, South Clifton Coronation Hall, South Clifton, Newark, Nottinghamshire, NG23 7BG

Friday 26 April 2024 

2pm – 7pm

High Marnham

Normanton On Trent Village Hall, South Steet, Normanton-On-Trent, NG23 6RQ

Saturday 27 April 2024

9am – 2pm

High Marnham online webinar: 

Webinar session



High Marnham proposals

Wednesday 24 April 2024

6- 7pm 


Register for the webinar here or call our Community Relations Team on 0800 073 1047 or email [email protected] to book.

National Grid partners with Met Office to boost capacity on the electricity transmission network - electricity transmission pylon and overhead lines at dusk

Get in touch

Do you have questions about the project? Or would you like to register your interest for us to keep in touch? Contact our Community Relations Team:

Email:[email protected]

Freephone:0800 073 1047 Monday to Friday 9am-5:30pm (An answering service is in place outside of these times)

Write to us: FREEPOST National Grid Projects (JBP) (no stamp or additional address information required)

You can also register your details to receive email updates on the project.

Register your email  

If you think our proposals could affect your land, please contact the Brinsworth to High Marnham Land Referencing Team at Ardent. You can call 0203 693 2500 or email [email protected]. Alternatively, you can write to Ardent, 36-38 Botolph Lane, London, EC3R 8DE.