Centrica plc

09 July 2026

Sizewell B life extension and regulated returns agreement

Centrica (the "Company") is pleased to confirm that a Heads of Terms for a 20-year regulated Contract for Difference ("CfD") agreement has been signed by UK Government which will extend the life of Sizewell B in Suffolk, enabling the 1.2GW nuclear power station, in which Centrica has a 20% share, to continue operating from 2035 to 2055.

Sizewell B will receive a guaranteed strike price of £70.50/MWh from April 2035 to March 2055 for the electricity it produces, based on 2025 prices and indexed to CPI inflation. The CfD framework removes exposure to merchant power prices, providing predictable inflation-linked revenues. Aligned with our investment framework, this underpins a fair return on life extension investment of approximately £800 million¹ which is expected to be funded through operating cash flows from the existing Nuclear partnership with EDF Energy over the next 15 years, with no requirement for additional equity to be injected. The contract with HMG is expected to be finalised later this year.

Sizewell B, the UK's only Pressurised Water Reactor, is one of the country's five operational nuclear power stations and provides zero-carbon electricity to power around 2.5 million homes a year, supporting the UK economy with clean and secure baseload energy.

In addition to Centrica's 20% ownership of the UK's operational nuclear fleet, the Company is also supporting the development of new nuclear in the UK. In July 2025, Centrica acquired a 15% stake in the neighbouring Sizewell C, a new 3.2GW power station under construction in Suffolk, for a phased investment capped at £1.3 billion under a Regulated Asset Base framework. Additionally, in September 2025, Centrica and X-energy signed a Joint Development Agreement for the UK's first advanced modular reactor fleet, targeting 6GW nationwide - enough to power 14 million homes. Hartlepool has been identified as the preferred first site for a ~1GW deployment, with the project currently advancing through HMG's Advanced Nuclear Pipeline assessment.

Chris O'Shea, Chief Executive of Centrica said:

"I'm delighted that Sizewell B will continue to play a key role in the UK's energy system for decades to come. Generating around 3% of the UK's electricity, Sizewell B is critical to delivering the reliable, zero-carbon baseload power that supports Britain's energy security, protects skilled jobs and underpins a more resilient economy.

"We welcome the constructive engagement with Government in reaching this agreement, providing the certainty needed to support the required investment. The agreement gives Sizewell B a clear, regulated framework through to the 2050s. This further strengthens Centrica's portfolio of long-term infrastructure assets with predictable earnings, which includes the neighbouring new nuclear power station, Sizewell C. It is good for the country, good for our customers and good for Centrica's shareholders."

Notes:

1. 100% share, 2023 prices. Centrica 20% share approximately £160 million.

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