Members of the UK Parliament’s Public Accounts Committee (PAC) have expressed serious concerns over the funding arrangement for the Sizewell C nuclear power station, warning that it poses significant financial risks to taxpayers and energy consumers. Sizewell C, a 3.2GW nuclear facility under construction on the Suffolk coast at Leiston, is anticipated to cost up to £48 billion and be completed by 2039. It is being developed beside the existing Sizewell A and B stations.

The project’s financing structure, approved last year, combines public and private investment but has been criticized for placing the bulk of cost overruns on consumers. Under the deal, the government is funding about £40 billion and retains a 44.9% equity stake, while a consortium of private investors—including Canadian pension fund CDPQ, British Gas owner Centrica, French energy company EDF, and Amber Infrastructure Group—holds the remaining 55.1%. Investors are guaranteed a minimum return, reportedly up to 13%, backed by levies on power bills.

The PAC’s report highlights that if construction or operational costs increase beyond projections, the government and private investors would face a relatively small share of additional expenses. For example, while private investors might contribute an additional £30 million, consumers could be responsible for up to £9.8 billion during construction and a further £12 billion over the 60-year operating contract, resulting in substantial increases in electricity bills. Over the 75 years encompassing construction and operation, the committee estimates total costs to consumers at about £136.5 billion in current money, with payouts to investors and lenders nearing £120 billion.

Sir Geoffrey Clifton-Brown, chair of the PAC, described the level of risk borne by taxpayers and consumers as “extraordinary,” warning that private investors stand to benefit from significant returns while households and businesses potentially face rising energy costs. The committee also pointed to the reactor design being used at Sizewell C, which has been implemented in France, Finland, China, and at the UK’s Hinkley Point C station. To date, none of these projects have been delivered on time or within budget, some experiencing delays of up to 14 years and marked cost overruns.

Experts such as Professor Simon Taylor of Cambridge University noted that promises of nuclear power reducing consumer bills were “naive,” underscoring that nuclear energy’s value lies in its reliability and carbon reduction rather than cost savings. Critics caution that in the event of substantial overruns, consumers would shoulder nearly all additional costs, with estimates suggesting that for every £1 added by investors, £727 could be passed on to energy users.

In response, Sizewell C’s chief executive Nigel Cann emphasized the project’s long-term benefits, including enhancing the UK’s energy independence and ultimately reducing electricity costs. A spokesperson from the Department for Energy Security and Net Zero pointed out that investors have incentives to complete construction efficiently and suggested that once operational, Sizewell C could save the energy system approximately £2 billion annually, resulting in lower costs for families across the country.

Sizewell C forms part of an ongoing trend of large-scale infrastructure projects in the UK experiencing budget challenges, alongside the HS2 rail network, the Elizabeth Line, and the Lower Thames Crossing. The debate over Sizewell C’s funding and risk distribution continues to raise important questions about future energy investment in the UK and the balance between public burden and private return.