National Grid is planning invest a record £35bn in the next five years to improve and expand the transmission network.

Today (18 December) it published the RIIO-T3 business plan for its National Grid Electricity Transmission (NGET) business, covering the period from April 2026 to March 2031.

It said it would invest more than £11bn to maintain and upgrade the existing networks, alongside construction works for the first three of its Accelerated Strategic Transmission Investment (ASTI) projects where project assessments have been approved.

It also announced a pipeline investment of around £24bn, which includes around £15bn to increase network capacity, most of which relates to the 14 further confirmed ASTI projects.

Pipeline investment also include additional potential projects that may be triggered by the UK government’s evolving priorities.

National Grid expects draft determinations from Ofgem in summer 2025, and final determinations in late 2025.

John Pettigrew, CEO of National Grid plc, said: “This plan represents the most significant step forward in the electricity network that we’ve seen in a generation.

“Through it we will nearly double the amount of energy that can be transported around the country, support the electrification of the industries of today and tomorrow; create new jobs; and support inward investment for the UK.

“It is an ambitious plan, set to future proof the network with strategic capacity and flexibility for the longer term.

“We’ve laid the foundations for its delivery through the steps we’ve already taken to progress ASTI projects, secure the supply chain, and fund the wider group. We have done this whilst keeping a relentless focus on consumer bills and affordability.

“It is now critical that Ofgem plays its part in developing an investable framework that will allow us to deliver at the unprecedented scale and pace that is needed to meet the UK’s ambitious climate goals."

Through its plans, National Grid also aims to connect 35GW of new generation and storage, and 19GVA of large demand customers such as data centres and gigafactories, as well as creating a further 26GW of future connection options.

It also aims to contribute to the group’s wider UK investment which supports 55,000 new jobs by 2030.