Cosa è successo

The House of Commons Committee of Public Accounts published its report on Sizewell C, the new nuclear power station being built in Suffolk, on 28 October 2026. As Jillian Ambrose reported for the Guardian, the cross-party committee of MPs opens by calling the deal "a terrible deal for the UK taxpayer". It follows the National Audit Office's report in May. The main points, checked against the committee's own report:

  • Cost and timing: the government expects Sizewell C to cost between £40.5 billion and £47.7 billion and to finish construction between 2039 and 2043. The committee notes that every plant built to the same reactor design has run late, over budget or both.
  • Who carries the risk: if costs rise to £47.7 billion, consumers would pay £9.8 billion more during construction and a further £12 billion over the plant's 60-year operating life (in real terms), while private investors would need to put in only an extra £30 million. Investor returns would still stay above 10% a year.
  • Ownership: the government holds 44.9%, with EDF on 12.5%, La Caisse 20%, Centrica 15% and Amber Infrastructure 7.6%, according to the NAO.
  • What the committee wants: Sizewell C Ltd to send it, within three months, the scenario analysis behind the cost estimates, and the company and the Department for Energy Security and Net Zero to report to Parliament every six months, including the expected effect on consumer bills.

The government disagrees. A spokesperson told the Guardian the report "completely ignores that investors are incentivised to complete construction as cheaply and quickly as possible", and that Sizewell C could save £2 billion a year across the energy system once it runs. The committee's report records the same claim from the department's economic case, which compares Sizewell C with other low-carbon options.

Cosa significa per la sua azienda

You are already paying a small charge. Sizewell C is funded under the nuclear Regulated Asset Base (RAB) model set up by the Nuclear Energy (Financing) Act 2022. Instead of being paid only once it generates, the company collects revenue while it is being built, regulated by Ofgem. The Low Carbon Contracts Company collects that money from every licensed electricity supplier in Great Britain for each MWh they supply, the same way as the Contracts for Difference levy. The NAO says consumers started paying after November 2025. For October to December 2026 the rate is £3.75 per MWh, about 0.38p per kWh, and it falls to £3.68 from January 2027. It was £4.68 from April to June 2026.

How it reaches your bill depends on your contract. Some business contracts pass third-party charges like this through as a separate line; on a fixed all-in price, your supplier will have allowed for it in the unit rate. As an illustration, a business using 20,000 kWh between October and December would carry about £75.08 of the levy before VAT if it were passed through at cost. Electricity covered by an energy intensive industries exemption certificate is left out.

What isn't known is the future size. The rate is reset every quarter, and the committee's warning is about what happens if costs climb towards £47.7 billion. The NAO's household estimate is £4 in 2025-26, rising to a peak of about £19 to £21 a year in the first decade of operation, but it says the government has not analysed how the cost will vary for commercial or industrial customers.

Your carbon figures don't change this year. Location-based Scope 2 uses the government's grid factor, which DESNZ publishes once for the whole year: 0.13096 kg CO2e per kWh for 2026, down from 0.177 in 2025. Nuclear is low-carbon generation, so once Sizewell C runs it should help push future factors down. That is at least 13 years away, so the cost arrives long before the carbon benefit shows in anyone's report. Our post on why the UK grid gets cleaner every year explains how the factor moves.

Cosa fare ora

  1. Check your contract for how non-energy and third-party charges are handled: passed through as they change, or fixed into the unit rate.
  2. Budget for small, moving levies. The nuclear RAB rate changes every quarter. Put a line for it in next year's energy budget and watch for the first six-monthly progress report, which should include the expected effect on bills if the government accepts the committee's recommendation.
  3. Cut kWh first. Every per-MWh charge, this one included, scales with use. Our post on why gas is behind most of the rise in electricity bills covers the bigger costs.
  4. Use the right year's factor for 2026 reporting, and keep your kWh records monthly.