Sundon – Cowley – Elstree Line is a 400kV overhead line from Sundon, Bedfordshire, UK, to Elstree, Hertfordshire, UK.

The project, which is currently in the planning stage, is expected to be commissioned in 2023.


Sundon – Cowley – Elstree Line is an overhead line that will be operated by National Grid. The line will carry alternating current (AC) through double circuit cable.

Sundon – Cowley – Elstree Line project development status

The construction works on the Sundon – Cowley – Elstree Line project will be commenced in 2022 and commissioning is expected in 2023.

About National Grid

National Grid Plc (National Grid) is an energy utility, which transmits and distributes electricity and natural gas. The company owns and operates electricity and gas transmission and distribution networks; and also serves as transmission owner and system operator. It provides installation and maintenance services to electricity metering and LNG suppliers; develops and operates electricity inter-connectors; and carries out LNG storage activities; and insurance and corporate activities. National Grid operates as an energy monopoly entity regulated by Ofgem. The company has operations in the UK and North Eastern US. National Grid is headquartered in London, Greater London, the UK.


All publicly-announced T&D Line & Substation projects included in this analysis are drawn from GlobalData’s Power IC. The information regarding the projects is sourced through secondary information sources such as country specific utility players, company news and reports, statistical organisations, regulatory body, government planning reports and their publications and is further validated through primary from various stakeholders such as power utility companies, consultants, energy associations of respective countries, government bodies and professionals from leading players in the power sector.