These price cap forecasts are now out of date – you can find our latest forecasts here: Predictions & Insights into the Default Tariff Cap (Price Cap).

Households face an extra £30 on their energy bills from April 2026 as rising charges to operate and maintain Great Britain’s electricity transmission network take effect. The data, from Cornwall Insight’s Default Tariff Cap (Price Cap) Predictor, shows the impact of these revised charges is set to rise to as much as £50 by 2028.

The transmission cost increase, which will be equivalent to a 1.5% rise on April’s average price cap bill, is due to a rise in the fees generators and suppliers pay to use the high-voltage grid. The higher fees – which are regulated by Ofgem – will filter down to consumers through electricity bills, driving Cornwall Insight’s forecast rise in the price cap.

The new data is based on the new indicative Transmission Network Use of System (TNUoS) Tariffs – Five-Year View, published  at the start of September by the National Energy System Operator (NESO). With the tariffs rising over the five year period.

Other non-wholesale elements of the cap – such as revised electricity and gas network costs, along with the new Nuclear Regulated Asset Base (RAB) charges to fund new nuclear power stations – are forecast to add more than £100 to the price cap in April 2026 compared with January.

Why are transmission costs rising?

  • Infrastructure investment needed to support the UK’s transition to a low-carbon energy system. As more renewable energy is generated in remote areas – such as onshore wind farms in Scotland and offshore wind farms in the North Sea – significant investment is needed to build new transmission lines and reinforce the grid to carry electricity around the country to where households are located.
  • The shift to a more electrified economy. The move to electric through technologies like heat pumps, and EVs is putting more demand on the grid, further increasing the need for investment to allow more power to flow at any given time.

TNUoS charges vary by region, reflecting the differing levels of investment needed to maintain and upgrade the transmission infrastructure across the country.

Based upon previous statements released by Ofgem as part of its view on the new regulated price controls, these bill increases were not totally unexpected, but highlight potential further financial pressures that households will face.

Crucially, the anticipated increase will predominantly be delivered through higher standing charges, which have been a point of increasing political and regulatory contention in recent years given volatility in energy bills amid the cost-of-living crisis, and the inability of households to avoid standing charges through more flexible consumption. While Ofgem has stated that it expects the TNUoS increases to be mitigated by the benefits of an expanded electricity transmission network, these may take time to emerge and will be felt by billpayers.

Dr Craig Lowrey, Principal Consultant at Cornwall Insight:

“Rising energy bills are never welcome, and this latest view of transmission charges – although only indicative – will add yet another cost to the long list of pressures on household finances. However, these costs are not just another item to tag onto the bill, they are essential to the long-term security and affordability of Great Britain’s energy system.

“For years, households have been at the mercy of global energy markets, with prices soaring and crashing in response to events happening thousands of miles away. It’s unpredictable, and it’s ultimately unsustainable.

“Investing in Britain’s transmission network means building a cleaner, more resilient energy system – one powered by renewables grown right here at home. Yes, it will take time. Yes, it will cost money. But every pound we invest today is a step toward a future where our energy is not only greener, but also more secure and, in time, more affordable.

“People rightly expect renewables to bring bills down, and they will. But first, we need to lay the foundations. There are a lot of costs involved in the transition, but the costs of doing nothing will be far greater.”

Reference:

1. Ofgem’s Typical Domestic Consumption Values (TDCVs), are set at 2,700 kWh per annum for electricity, and 11,500 kWh per annum for gas.

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