Sizewell C

United Kingdom

The financing of Sizewell C (SZC) represents a transformative moment in UK infrastructure financing, introducing the Regulated Asset Base (RAB) model to nuclear development. This is the first time that financial investors and lenders have invested in a new nuclear build globally, which was previously viewed as not achievable. SZC’s unique structure blends government and private sector financing across both equity and debt.

The structure has been developed with careful calibration of incentives, protections, and controls, building upon lessons learned from the successful Thames Tideway Tunnel RAB model implementation while adapting the model for the unique challenges of nuclear construction and operations. The RAB model's approach to risk rebalancing by allowing regulated consumer contributions facilitating revenue throughout construction for investors, accompanied with the Government Support Package to protect against low-probability, high-impact risks, attracted institutional investors whose typical risk tolerance previously made investment in nuclear and complex greenfield assets very difficult. The deal overcame significant challenges: the scale and complexity of the financing required, investor scepticism of the track record in nuclear construction, and the need to balance public accountability with private sector efficiency. Significantly, SZC has established best practice for UK energy infrastructure, demonstrating the model as suitable for replication in future nuclear projects and other large-scale infrastructure projects. The structure provides a template for balancing public interest, private capital, and delivery efficiency that has attracted international attention and positions the UK as a leader in innovative infrastructure financing.