What Sizewell B’s New Lifeline Means for UK’s Nuclear Energy

Sizewell B, one of the UK’s largest, most powerful and most efficient nuclear power plants, has received a ‘life extension’ of 20 years.

The EDF-operated facility has been operational since 1995 and had been scheduled for closure in 2035, in keeping with the general 40-year lifespan of nuclear plants.

However, the French energy giant and the UK Government have agreed to keep the site running until 2055 after Westminster offered EDF a fixed, subsidised price for its future output of electricity.

Tom Greatrex, the CEO of the UK’s Nuclear Industry Association, points out the significance of this moment.

“Sizewell B is the cleanest, most productive and most reliable plant in the whole country, so extending its life is one of the best things we can do to build an affordable and reliable clean power system,” he says.

“Nuclear makes a unique and irreplaceable contribution to our energy security, so we should also continue to deploy new nuclear projects, to renew the benefits from clean, secure and reliable electricity for decades to come.” 

What the plant has delivered so far

Since being commissioned in 1995 Sizewell B has produced more than 270TWh of low-carbon electricity, placing it among the UK’s most productive power plants of all time.

According to EDF that volume would be enough to meet the needs of every household in Suffolk and Norfolk for more than a century.

Today, the station currently supplies around 3% of the UK's total electricity output which, for context, is enough to power around 2.5 million homes.

Crucially, Sizewell B produces baseload power, meaning that unlike wind and solar it runs continuously regardless of weather conditions, making it a stable anchor for the British energy grid.

The financial detail

EDF has committed to funding a major refurbishment of the plant during scheduled outages over the next fifteen years.

That refurbishment is expected to cost around US$1.02bn.

Centrica, which has a large stake in the plant, has also backed the deal and the investment required to keep the station running through to 2055.

“I’m delighted that Sizewell B, in which Centrica owns a 20% share, will continue to play a key role in the UK’s energy system for decades to come,” says Centrica’s CEO, Chris O’Shea.

“Sizewell B is critical to delivering the reliable, zero-carbon baseload power that supports Britain’s energy security, protects skilled jobs and underpins a more resilient economy,” he adds.

This point about resilience and energy security has been key to the government’s decision to keep Sizewell B running.

Had this arrangement been in place during the energy price crisis triggered by Russia's invasion of Ukraine, the UK Government suggests that consumers could have saved around US$2.54bn.

‘Delivering a golden age of nuclear’

Simone Rossi, the CEO of EDF UK, sees the life extension as part of his company’s broader strategy.

“Global events demonstrate time and again how vital it is for the UK to secure long term, low-carbon, homegrown electricity which protects British households and businesses from market volatility,” he explains.

Simone adds that extending existing plants alongside building new ones is “central to EDF’s strategy”.

The UK’s Energy Secretary, Ed Miliband, who has made clear the government’s ambitions to invest heavily in nuclear, summed up the impact of this deal succinctly.

“Nuclear power is vital for our energy security, and this extension will help produce the clean power our country needs,” he says.

Elsewhere, Lord Patrick Vallance, the UK’s Minister for Science, Innovation, Research and Nuclear, highlights the jobs that will be created by the renewed agreement.

“This deal protects billpayers and boosts the country's energy security by continuing to provide clean, secure power for millions of households,” he says.

“By backing Sizewell B, we are delivering a golden age of nuclear and maintaining 900 skilled jobs in Suffolk."

What comes next

It is important to note that the agreement between EDF and the UK Government is what is known as a ‘Heads of Terms’, which is not, in fact, a finished contract.

Both parties will still need to negotiate a long-form agreement and secure regulatory approvals before the deal is truly finalised.

Government officials say this is expected to happen in a matter of months.

Notably, this extension to Sizewell B will see it continue to produce energy long after its intended successor, Sizewell C – which is being constructed just a stone’s throw away – is due to be completed in the late 2030s.

With both plants firing at full capacity and the UK’s new investments in small modular reactors, or SMRs, set to be operational by then, the country’s nuclear energy portfolio will be in rude health.