Why building a copy gives Sizewell C an advantage | Tilly Spencer

Last week I spoke at the Energy Landscape Conference about something that might sound a little contradictory. Sizewell C is a near identical copy of Hinkley Point C; but we’re planning to build it very differently.

That might seem strange. Why change the way you build something if the design is already proven?

The answer is that we’re not changing what we’re building. We’re changing how we build it. That distinction is important if we’re going to deliver nuclear power more efficiently, reduce costs, and provide value for consumers across the UK.

The country needs more reliable, affordable, and low-carbon electricity. Of course, renewable energy will play a significant role in our future energy system. But we also must take into account what happens when the wind isn’t blowing and the sun isn’t shining.

That’s where nuclear power comes in.

Sizewell C will generate enough clean electricity for around six million homes, operating for at least 60 years. It will also help make the UK’s energy system around £2bn cheaper every year.

But we know the nuclear industry has questions to answer about the cost and delivery of major projects.

For too long, our country has approached nuclear construction through one-off designs, often after decades without building anything. Skills have been lost, supply chains have disappeared, and projects have effectively had to start again.

Sizewell C is different because we’re not starting from scratch.

Around 85 per cent of our above-ground design will be the same as Hinkley Point C. We have the benefit of an established supply chain, experienced teams and, crucially, a decade of construction lessons that have been learned.

We’re already seeing what that experience can deliver. At Hinkley Point C, construction of the second reactor unit is around 30 per cent more efficient than the first.

Our job is to take that learning further.

Building smarter, not just building again

One of the biggest opportunities is modular construction.

Rather than carrying out every task on a busy construction site, we can manufacture more components in controlled factory environments and bring them to site ready for installation.

At Hinkley Point C, four precast room modules were installed in Unit 1, rising to 26 in Unit 2. At Sizewell C, we’re planning to use 195 across both units.

We’re also looking at how automation can improve productivity. Tens of thousands of welding tasks could be moved off site and completed using automated processes. Advanced steel fixing techniques could save millions of labour hours.

This also means we can create safer working conditions, improve quality control, ensure there are fewer delays, and operate with greater certainty over costs and schedules.

We’re also developing a Digital Control Tower to track materials and equipment from manufacture through to installation. The ambition is to bring the sort of visibility and efficiency we’ve come to expect from modern logistics into nuclear construction.

The benefits could extend beyond Sizewell C. So, if we can demonstrate better ways of delivery, then there are lessons here for other projects in the years ahead.

Innovation goes beyond construction

We’re also doing things differently in how Sizewell C is financed.

The cost of raising capital has always been one of the biggest challenges for nuclear projects. Our financing model is designed to attract long-term investment, share risk more effectively and reduce financing costs, which ultimately benefits consumers.

But none of these improvements will happen without the right culture.

Safety, quality, and technical excellence will always be non-negotiable. Alongside that, we want people to question established ways of working, share lessons and find opportunities to improve.

Replication and innovation are sometimes treated as opposites. I don’t see them that way.

Replication gives us the confidence of knowing what we’re building. Innovation gives us the opportunity to build it better.

Hinkley Point C has helped the UK rebuild its nuclear construction capability. At Sizewell C, we now have the opportunity to show what happens when we build on that experience.

And if we get it right, we’ll not only deliver a power station that provides clean electricity for generations. We’ll help demonstrate that the UK can deliver major infrastructure more efficiently, with greater certainty, and at a lower cost.