Nick Winser's independent report on Accelerating Electricity Transmission Network Deployment was published in June 2023. It outlined the need for unprecedented development of Britain's transmission infrastructure to meet the UK Government's commitment to a fully decarbonised electricity system by 2035, subject to security of supply considerations1.
The report's central finding, as later summarised by the Electricity System Operator, was that network build is the most impactful lever available for reducing the cost of balancing the grid. New network can take up to 14 years to build, far longer than connecting a new renewable generation source, creating a lag between new generation connecting and the infrastructure needed to transmit that clean energy coming online1. The ESO said in March 2024 that it had set out network recommendations for investment into the 2030s in its Beyond 2030 report1.
"In June 2023, Nick Winser's independent report on Accelerating Electricity Transmission Network Deployment outlined the need for unprecedented development of Britain's transmission infrastructure to meet the UK Government's commitment for a fully decarbonised system by 2035, subject to security of supply considerations."
The report sits alongside figures on what balancing the system costs households. In 2023/24, Balancing Services Use of System (BSUoS) charges contributed around 4% of electricity bills for an average domestic consumer, about £4 a month on a typical domestic electricity bill1. Overall balancing costs fell to £2.4bn in 2023/24 from £4.1bn in 2022/23, and net balancing volumes fell to 10.8 TWh from a 2020/21 peak of 21.4 TWh1.
Thermal constraint costs, the cost of managing congestion on the transmission network, were the largest single component of balancing costs at 40% in 2023/24, up from 36% in 2022/231. The ESO projects balancing costs to rise out to 2030, with constraints the main driver, as up to 80 GW of generation connects by 2030 in its most ambitious decarbonisation scenario1. It estimates its own initiatives create savings worth around £18bn before 20301.
| Measure | 2022/23 | 2023/24 |
|---|---|---|
| Total balancing costs | £4.1bn | £2.4bn |
| Net balancing volumes | not given | 10.8 TWh |
| Thermal constraint share of balancing costs | 36% | 40% |
| Reserve volumes | 5.7 TWh | 4.8 TWh |
Why it matters for households
Transmission infrastructure determines how much of the electricity generated in one part of Britain can reach homes in another. Where the network is congested, the system operator pays generators to turn down or up, and those costs flow into BSUoS charges on bills. The Winser report's argument is that building network faster reduces that congestion, and therefore the constraint costs that households ultimately fund through the transmission and balancing charges that sit behind the unit rate.
For a household, the practical link runs through the electricity transmission network itself: the pylons, substations and cables that connect generation to demand. A grid that cannot move power freely also affects how much balancing and frequency response capacity has to be bought to keep the system stable, and how much power Britain needs to import or export through electricity interconnectors. The ESO's figures show the balancing component of a domestic bill was about £4 a month in 2023/24, and it projects that component to rise to 2030 before network investment takes effect1.
What happens next
The ESO's May 2024 report states that balancing costs are projected to rise out to 2030, and that it will continue to work with Ofgem, Government and industry to realise savings1. It cites the Government's Transmission Acceleration Action Plan and the Review of Electricity Market Arrangements as containing measures that can bring balancing costs down1. The report does not set out a timetable for the Winser report's recommendations to be implemented, and no delivery dates for specific transmission projects have been reported in it.
Sources1 cited
- PowerPoint Presentation, neso.energy