In a government announcement, ministers said Sizewell B will continue operating until 2055 after terms were agreed with EDF for a 20-year lifetime extension. The Suffolk station currently supplies about 3% of UK electricity, which the government equates to power for roughly 2.5 million homes. For Policy Wire readers, the immediate point is continuity. Rather than replacing this output in 2035, when the plant had been expected to close, the government is seeking to keep an existing source of low-carbon generation on the system for a further two decades.
The commercial mechanism is a 20-year Contract for Difference beginning in 2035, with a strike price of £70.50 in 2025 prices. The government said the arrangement has support and investment from Centrica, which owns a 20% stake in Sizewell B. That timing matters. Support is due to begin at the station's original closure date, so the policy is framed as a bridge into the plant's extended life rather than a new settlement for current operations. In practical terms, the agreement is intended to give the operator a clearer revenue framework for the years after 2035.
The government argues that extending Sizewell B will lower the overall cost of the electricity system when compared with building alternative generation to replace it, while also reducing exposure to volatile fossil fuel prices. In public statements, Energy Secretary Ed Miliband, Chancellor Rachel Reeves and Science Minister Lord Vallance each presented the extension as both a consumer protection measure and an energy security measure. The most striking figure in the announcement is the claim that consumers would have saved about £2 billion during the energy price crisis that followed Russia's invasion of Ukraine if the station had been operating under this agreement, using 2025 prices. That is a modelled estimate rather than a historical outcome, but it shows how ministers want the value-for-money case to be understood.
Employment and skills are a second pillar of the announcement. The government said the extension is expected to support around 900 skilled jobs at the site, preserving operational expertise in a part of the power system where long lead times and specialist training remain significant constraints. The wider sector context is also part of the message. Citing the Nuclear Industry Association, the announcement says nearly 100,000 people work in nuclear roles across the UK. Keeping Sizewell B open for longer would therefore do more than retain one plant's workforce; it would help sustain supply chains and capability while other nuclear projects move through planning, financing and construction.
The agreement was announced alongside the government's broader nuclear programme, including support for small modular reactors at Wylfa in Anglesey and the final investment decision for Sizewell C. Ministers said Sizewell C is expected to generate enough electricity for the equivalent of 6 million homes and support 10,000 jobs at peak construction. Set against that wider programme, Sizewell B's extension serves a different policy purpose. It does not add a new station to the grid, but it reduces the risk of a gap opening between the retirement of existing reactors and the arrival of replacement low-carbon capacity.
Company statements in the release show alignment between Whitehall and the plant's owners, although for different reasons. EDF UK focused on the value of long-term domestic low-carbon generation during periods of international market instability, while Centrica described the agreement as the certainty needed to back the investment required for continued operation. Centrica's role is not incidental. As the owner of a 20% share in Sizewell B, its support matters both financially and operationally. The announcement therefore points to a three-way settlement in outline: government backing, EDF as operator, and shareholder support for the investment case.
The cautionary note sits in the small print rather than the headline. The government said the parties have agreed Heads of Terms, but the final deal still depends on drafting the long-form contract and securing all necessary regulatory approvals. That means the announcement should be read as an agreed policy and commercial framework, not yet a completed legal settlement. For officials, investors and large energy users, the next question is whether those contractual and regulatory steps are completed on the timetable needed to keep Sizewell B running through to 2055.