UK Audit Office: Sizewell C Build Will Add Up to £19 to Annual Electricity Bills

Overview

• The National Audit Office, in a report published Wednesday, estimates about £4 will be added to a typical household’s electricity bill in 2025–26, rising to £17–£19 when Sizewell C starts up.
• Sizewell C is being funded through a Regulated Asset Base model that adds a levy to bills during construction, with the UK Government holding a 44.9% stake alongside La Caisse, Centrica, EDF and Amber Infrastructure.
• The report warns that returns paid to investors could leave consumers covering £4 billion to £4.5 billion unless costs fall or the build finishes sooner.
• DESNZ says the plant could deliver up to £18 billion in net consumer benefits and save about £2 billion a year across the energy system once it is running, with construction-phase impacts averaging about £1 per month on a typical bill.
• The project is forecast to cost about £38 billion, construction began last year, completion is targeted for summer 2039, it is expected to power around six million homes for 60 years, and the NAO urges close monitoring of risks to taxpayers and billpayers.