Why UK consumers will only pay £1 a month for Sizewell C during construction

The UK Government’s £38 billion final investment decision on the Sizewell C nuclear power plant has drawn attention not just for its size and strategic scope, but for how little it is expected to cost individual British households in the short term. Despite being one of the largest publicly backed infrastructure projects in decades, the average household will see only a £1 per month increase on electricity bills during the construction phase, a figure confirmed in official documents from the Department for Energy Security and Net Zero.

This relatively small impact is being viewed by institutional investors and policymakers alike as a proof point for the viability of the Regulated Asset Base (RAB) model in large-scale nuclear project funding—especially in an era of rising living costs and energy price volatility.

How does the regulated asset base model keep monthly costs low for consumers?

Unlike previous nuclear funding approaches that required full public financing or post-construction investor payback, the RAB model allows Sizewell C developers to begin recovering approved construction costs through regulated payments from electricity customers. This mechanism spreads the financial burden over the duration of the build and into long-term operations, lowering the upfront cost pressure for both the government and investors.

From a consumer standpoint, it means that rather than facing unpredictable future levies or tax hikes, the cost is capped at a manageable, predictable £1 per month over the roughly 10-year construction timeline. The logic, according to institutional backers like Centrica and La Caisse, is that this upfront contribution reduces the need for high-cost government borrowing while helping lock in stable, inflation-linked returns for long-term pension funds and infrastructure investors.

According to Energy Secretary Ed Miliband, the RAB model “balances short-term affordability with long-term investment needs,” enabling Sizewell C to move forward without burdening working families with large bill hikes.

What role does government oversight play in safeguarding consumer interests?

Oversight of the RAB revenue mechanism is handled by Ofgem, which acts as the regulatory counterparty to ensure transparency and cost discipline. Under the model, all investor returns and cost recovery timelines must be reviewed and approved periodically to avoid excessive profit-taking or unplanned consumer charges.

Additionally, cost escalation beyond the £38 billion projected build target—or even the £47 billion upper limit inclusive of contingency—triggers a review mechanism. In such cases, investors risk clawbacks and lower earnings unless specific milestones are met. Analysts believe this “in-built penalty structure” encourages developers and suppliers to control cost overruns, which have historically plagued nuclear builds like Hinkley Point C.

The UK Government’s decision to become the largest equity shareholder, with a 44.9 per cent stake, also reinforces direct accountability to taxpayers and energy users. Public ownership at this scale ensures that the benefits of low-cost, stable power generation flow back into public finances and consumer pricing.

What are the long-term savings potential for households after Sizewell C becomes operational?

Once online—projected between 2035 and 2037—Sizewell C is expected to generate 3.2 gigawatts of electricity, equivalent to powering around six million homes. As a firm, baseload energy source, nuclear provides a critical counterbalance to intermittent renewable sources like wind and solar, which currently require backup generation and costly balancing payments.

The Department for Energy Security and Net Zero estimates that the project will deliver up to £2 billion in annual savings across the electricity system once operational, due to reduced reliance on fossil fuel imports and price fluctuations. Those systemic savings are expected to feed directly into lower wholesale power prices, eventually translating into lower bills for households.

This dynamic is particularly relevant in light of the UK’s broader net zero targets and rising electrification of heating and transport. With more demand shifting to the grid, the need for stable, predictable low-carbon generation becomes central to managing household costs over the long term.

What makes this model politically and economically relevant now?

The £1 per month figure is not just a talking point—it’s a key signal to voters and markets that large nuclear projects can be both scalable and socially palatable. Past criticism of nuclear centred on spiralling budgets, opaque financing, and consumer exposure to poorly managed costs. By capping exposure during the build phase and enforcing accountability through regulatory oversight, Sizewell C flips that narrative.

Policymakers hope this proves that nuclear projects can co-exist with affordability goals, especially in the context of rising living costs. Institutional investors, meanwhile, are watching closely to determine if this hybrid funding model—mixing government equity, pension fund capital, and consumer-backed returns—can be duplicated for future builds, including small modular reactors (SMRs).

Could this model set a wider precedent across Europe?

Many European nations face similar energy dilemmas: declining baseload capacity, volatility in imported gas markets, and decarbonisation targets that demand new infrastructure investment. If Sizewell C delivers as expected—with controlled costs, stable returns, and minimal consumer disruption—the RAB framework could be exported beyond the UK.

Countries such as Poland, the Czech Republic, and Finland are exploring new nuclear builds and modular reactor programs. Analysts suggest that Sizewell C’s RAB success could serve as a financing prototype, reducing dependence on sovereign debt while attracting global infrastructure capital to net zero-aligned energy assets.