On a quiet stretch of the Suffolk coastline, a monumental infrastructure project is taking shape. Sizewell C, a nuclear power station poised to become one of the most significant contributors to the UK’s energy supply, is no ordinary development. It embodies a growing urgency, to decarbonise, to reduce foreign energy dependence, and to build long-term resilience into the grid. But behind the political speeches and government pledges lies a complex, multi-billion-pound undertaking that has sparked both cautious optimism and fierce resistance.
At stake is not just the 3.2 gigawatts of electricity that the station is expected to generate, enough to power six million homes, but the future of how the UK funds, builds, and justifies major energy infrastructure. In an era where climate targets and geopolitical tensions are converging, Sizewell C is no longer merely an energy project. It is a litmus test for Britain’s ambitions and its appetite for bold, state-backed solutions.
Why Here Why Now The Strategic Case for Suffolk
The decision to site Sizewell C next to the existing Sizewell A and B reactors is no coincidence. The area already houses the skilled labour, grid connections, and regulatory know-how needed to support nuclear operations. Enco, an independent consultancy, went as far as to call it “the best-prepared nuclear energy site in modern history”. Sizewell’s nuclear legacy stretches back to the 1960s. Now, as older reactors across the country edge towards retirement, the region is preparing for a new chapter.
The rationale is as strategic as it is geographical. The UK’s ageing fleet of reactors is dwindling fast, with only Sizewell B expected to remain online into the 2030s. Replacing this capacity is essential to maintain a stable baseload and meet the government’s legal obligation to reach Net Zero emissions by 2050. Sizewell C, with its robust design and long lifespan, is central to this goal.
But the choice to use European Pressurised Reactor (EPR) technology, also deployed at Hinkley Point C reveals deeper intentions. By replicating the Hinkley Point C blueprint, the government and EDF hope to shortcut the long delays and cost overruns that have historically plagued large-scale nuclear builds. Over 90% of Sizewell C’s design is identical to Hinkley’s. Supply chains have already been tested. Regulatory hurdles have been navigated. In theory, it should all run more smoothly this time around.
In practice, replication brings its own complications. Hinkley’s costs have ballooned from £18 billion to potentially over £40 billion, with completion delayed by six years. While Sizewell C is meant to learn from these mistakes, there is no guarantee that efficiencies will outweigh the complexities of EPR technology, UK-specific design modifications, and the immense logistical demands of nuclear construction.
Who’s in Charge The Changing Face of Ownership
Sizewell C’s corporate structure has shifted dramatically since its early days. Originally backed by a consortium including EDF and China General Nuclear (CGN), the project’s geopolitics changed course in 2022. Amid growing concerns over Chinese involvement in sensitive UK infrastructure, the British government invested £679 million to become a 50% partner in the project. This not only forced CGN’s exit but marked the return of majority public ownership in British nuclear for the first time in over three decades.
As of mid-2025, the government holds around 83.5% of the project, with EDF retaining a minority share. Plans are underway to bring in private capital, reducing the government’s holding before the Final Investment Decision (FID). The shift away from foreign state-backed partners towards a domestically controlled consortium signals a strategic pivot. It underscores a growing willingness by Westminster to reassert control over critical national assets, a notable departure from the privatisation orthodoxy that has governed energy policy since the 1980s.
Fun Fact: Sizewell C will be the first majority British-owned nuclear plant built in over 30 years, reversing decades of private and foreign-dominated development models.
Ready to Build Navigating Red Tape and Securing Cash
Securing the necessary approvals for Sizewell C has not been straightforward. The Development Consent Order was granted in July 2022, despite opposition from the government’s own Examining Authority, which flagged concerns over biodiversity and local water supplies. The nuclear site licence followed in May 2024, clearing one of the final regulatory hurdles before construction.
The price tag remains contested. While some government estimates place the total cost around £20 billion, others suggest it could climb as high as £35 billion. EDF has rejected reports of a £40 billion figure, but the variance underscores the inherent uncertainty. A significant tranche of funding £14.2 billion, was allocated by the government in 2024, bringing its total financial backing to £17.8 billion. This is the first direct public investment in a new nuclear build since Sizewell B, approved in the 1980s.
Construction officially began in January 2024, although some sources suggest early 2025. The build is expected to take between nine and twelve years, pushing the station’s first output into the mid-2030s. Much depends on whether additional private backers come on board. The government’s commitment alone won’t be enough. The use of the Regulated Asset Base (RAB) model is meant to attract further investment , and its success or failure could shape the future of nuclear finance in the UK.
What It Delivers A Backbone for UK Energy Security
Sizewell C’s 3.2 GW capacity is a significant addition to the UK’s electricity landscape. Once operational, it is expected to generate power for around six million homes, supplying 7–8% of the country’s total electricity demand. Importantly, this is baseload power, stable, 24/7 output not subject to the whims of weather or daylight.
This reliability is one of the reasons nuclear is viewed as a vital complement to the UK’s growing renewable portfolio. Wind and solar may now dominate new capacity builds, but they’re inherently intermittent. Nuclear offers a clean, predictable counterbalance. As the UK phases out gas and coal, and electrifies everything from cars to boilers, the need for steady supply becomes urgent.
Sizewell C’s role is not simply to replace retiring reactors; it is part of a national reboot. The UK currently operates with about 5.9 GW of nuclear power. However, most of this capacity will disappear by 2030. The combined output of Sizewell C and Hinkley Point C will more than double the nuclear share, provided both come online on time.
How It Compares The Scale and Reach of Sizewell C
To put Sizewell C into perspective, consider that Sizewell B, the UK’s most recent operating nuclear plant, has a capacity of 1.2 GW. Hinkley Point C will match Sizewell C at 3.2 GW, but is also battling delays. Most of the older fleet, based on Advanced Gas-cooled Reactor (AGR) technology, are already in the process of winding down.
By the time Sizewell C is operational, it may be standing alone alongside Hinkley Point C in anchoring Britain’s nuclear fleet. The government’s aim to expand nuclear capacity to 24 GW by 2050 hinges not only on SMRs and future innovations, but on ensuring projects like Sizewell C deliver what they promise. Their success will either justify or discredit the faith being placed in nuclear as a pillar of Britain’s energy transition.
Comparative Snapshot: UK Nuclear Capacity
PlantStatusCapacity (GW)Reactor TypeExpected Lifespan
Sizewell C Under construction 3.2 2 x EPR Gen III+ 60 years
Hinkley Point C Under construction 3.2 2 x EPR Gen III+ 60 years
Sizewell B Operational 1.2 1 x PWR To 2055
Hartlepool (example AGR) Decommissioning ~1.2 2 x AGR 40–50 years
Stability in a Volatile Market Why Nuclear Still Matters
As global energy markets react to supply shocks, price volatility, and political unrest, the case for domestic, firm power grows stronger. Sizewell C is pitched as part of the solution, offering low-carbon, homegrown energy that reduces dependence on imported gas and oil. Government officials have framed it as critical for “national resilience”.
While wind and solar are cheaper per MWh in many contexts, they can’t currently provide grid stability on their own. Batteries and other forms of storage are improving, but not yet sufficient to replace the firming power provided by plants like Sizewell C. The result is an emerging consensus that a mixed energy portfolio, with nuclear as the baseload and renewables as the primary expansion focus, is the most pragmatic path forward.
Analysts suggest that by replacing fossil gas generation and stabilising the grid, Sizewell C could help save up to £1.5 billion annually across the electricity system. That’s based on reduced fuel imports, lower wholesale price volatility, and less need for costly backup capacity. But such savings hinge on timely delivery and careful cost control, areas where nuclear’s recent record has been mixed.
Decarbonisation at Scale Sizewell C and the Path to Net Zero
Sizewell C’s contribution to Britain’s Net Zero strategy is not merely theoretical. Its scale and reliability make it one of the few technologies capable of displacing vast quantities of fossil fuel-generated electricity over decades. Each year it operates, the plant is projected to avoid around 9 million tonnes of CO₂ emissions, emissions that would otherwise come from gas-fired power stations.
This isn’t just a numbers game. For the UK to meet its legal target of net-zero greenhouse gas emissions by 2050, the electricity grid must be almost completely decarbonised by the early 2030s. Nuclear is one of the only low-carbon generation methods that can provide constant output, unaffected by weather. It fills a crucial gap, especially during periods of low wind or solar production.
Without large-scale nuclear or equivalent storage capacity, the UK would need to build a dramatically oversized renewable system, paired with expansive storage and flexible backup. This may be technically possible but comes with huge cost and land use implications. Sizewell C, by offering firm, clean power, helps make the entire system more balanced and affordable.
The Carbon Footprint Question How Nuclear Compares to Other Sources
Critics often focus on the carbon emissions involved in building large nuclear stations. It’s true, construction is energy-intensive, and materials like concrete and steel carry embedded emissions. But when averaged over a plant’s full operational life, the carbon cost of nuclear is remarkably low.
According to the IPCC, the median lifecycle emissions of nuclear power stand at 12g CO₂/kWh, the same as onshore wind, and significantly below solar PV, which averages around 48g CO₂/kWh. The UN Economic Commission for Europe (UNECE) puts nuclear even lower, at around 5.1 to 6.4g CO₂/kWh.
In fact, a lifecycle assessment conducted specifically for Sizewell C suggests it may produce half the emissions of the IPCC’s global average for nuclear. This places it among the cleanest energy sources ever developed at scale. For comparison, modern gas plants emit roughly 490g CO₂/kWh, and coal over 800g CO₂/kWh.
A Boost for the Economy Jobs, Training, and Industry Benefits
Beyond clean energy, Sizewell C is expected to provide a substantial economic uplift, particularly across the East of England. At peak construction, the site will employ around 10,000 workers, with roughly 2,000 drawn from the local area. An additional 1,500 apprenticeships are planned across the project’s lifecycle.
Once operational, the plant will support about 900 permanent roles, most of them highly skilled and well-paid. These jobs represent long-term employment in a sector not easily outsourced, helping anchor economic stability in the region for decades.
A key benefit is the stimulus to the UK supply chain. The project has pledged that over 70% of its construction contracts will go to British firms, involving more than 3,500 domestic suppliers. So far, over £330 million in contracts have been signed with UK businesses, and more than £4.5 billion is expected to be spent with local and regional companies over the construction period.
The economic case is clear: local gross value added (GVA) from employment alone is projected at £1.3 billion, with a further £140 million stemming from associated sites and services. However, this rapid growth is not without complications. Infrastructure, housing, and even tourism are being stretched in some places. Rent increases in Leiston, for example, have prompted concerns about displacement and affordability.
The Price of Progress Environmental Trade-offs and Safeguards
Sizewell C is being built in one of the UK’s most ecologically sensitive areas, the Suffolk Coast and Heaths Area of Outstanding Natural Beauty. Nearby lie Sites of Special Scientific Interest and the famous RSPB Minsmere Reserve. For critics, the location alone is enough to disqualify the project. For supporters, its careful environmental planning makes it a model for future large infrastructure.
The site includes a sea defence wall designed to withstand one-in-10,000-year storms and accommodate sea-level rise. Water for construction is being sourced through a temporary desalination plant, powered by Sizewell B, to avoid straining local freshwater resources. During operation, the plant will draw cooling water from the North Sea, a common practice, though one that requires close marine monitoring.
To mitigate its ecological footprint, Sizewell C has committed to creating over 600 acres of new habitat, including rehoming protected species and expanding the Wild Aldhurst reserve. A £12 million landscape fund and a £78 million community trust are part of the compensation and mitigation package. The project also claims that less than 0.2% of the Suffolk AONB will be physically impacted.
Still, environmental groups remain unconvinced. Concerns persist around marine impacts, long-shore drift disruption, and the risk that Sizewell may become an “island” due to rising seas. The debate boils down to values: should urgent national energy needs outweigh local ecological costs? The government’s planning approval, granted despite reservations from its Examining Authority, suggests that for now, the answer is yes.
The New Nuclear Finance Model Sharing Risk Through RAB
A key innovation for Sizewell C is its use of the Regulated Asset Base (RAB) funding model. Unlike previous nuclear projects, where developers earn money only once electricity flows to the grid, RAB allows investors to start earning a regulated return during construction. This return is funded by a small levy on consumer bills.
The idea is to reduce overall project risk, attract private capital at lower cost, and incentivise on-time, on-budget delivery. For Sizewell C, this marks the first use of RAB for a nuclear project in the UK. The model was enabled by the Nuclear Energy (Financing) Act 2022 and is overseen by Ofgem, with the Low Carbon Contracts Company acting as financial counterparty.
Critics point out that RAB exposes consumers to construction risk, if the project overruns or overspends, households could end up footing more of the bill. Early estimates suggest Sizewell C could add roughly 2.31p per kWh to bills during its operational phase. The challenge will be ensuring that the RAB model’s cost-savings outweigh the risks and that consumers are adequately protected through oversight and transparency.
Public Perception Is Support for Nuclear on the Rise?
Public opinion on nuclear power is gradually warming. Polls from Savanta in 2023 found that 40% of UK adults support nuclear energy, with opposition dropping compared to previous years. Older adults and men are more supportive; younger demographics and women show more hesitation, a gap that campaigners say must be addressed through better outreach.
Support for nuclear still lags behind renewables, but is stronger than support for coal or, increasingly, gas. As climate change climbs the agenda, and energy independence becomes a political priority, nuclear’s reputation is slowly rehabilitating. The government’s investment in Sizewell C, paired with plans for Small Modular Reactors (SMRs), reflects this shift.
However, local opposition remains strong. Groups like Stop Sizewell C argue that the plant is too slow, too expensive, and too risky, especially for such an ecologically rich area. Legal challenges have been mounted (and rejected), and community forums remain lively. Yet polling shows that 70% of East Anglia residents believe the project will bring valuable jobs, suggesting a more complex local picture.
The Bigger Picture Sizewell C in the UK’s Energy Future
Sizewell C is more than a single project. It is a test bed for the future of nuclear energy in the UK. Alongside Hinkley Point C and a growing SMR programme, it is central to the government’s ambition to reach 24 GW of nuclear capacity by 2050.
Small Modular Reactors, being developed by Rolls-Royce SMR, promise faster, cheaper builds, potentially deployed on brownfield sites across the country. But they’re not ready yet. Sizewell C, for all its complexity, is real, funded, and underway. Its success will determine whether the UK’s nuclear future is one of bold momentum or cautious retreat.
It will also inform whether RAB financing, domestic supply chain strategy, and community engagement models are fit for purpose. Get it right, and Sizewell C could be the turning point. Get it wrong, and it may set the whole sector back another generation.
The Verdict A High-Stakes Gamble with National Consequences
The Sizewell C project is as ambitious as it is controversial. It promises clean, reliable power for generations a critical bulwark against climate change and foreign energy shocks. But the stakes are high. Timelines are tight. Public scrutiny is intense. And the memory of Hinkley Point C’s spiralling costs looms large.
Whether Sizewell C ultimately becomes a success story or a cautionary tale will depend on meticulous execution, transparent governance, and a strong social contract with the communities and consumers it impacts. What’s clear is that the plant symbolises a new chapter, not just for British nuclear power, but for how the country approaches infrastructure, energy, and long-term planning.
As the cranes rise over Suffolk, the question is no longer just about whether we can build it. It’s whether we can build it better.
