The Hinkley Point nuclear site, on the Somerset coast, should have begun powering around 6m homes well over a year ago.
Instead, the 160-hectare (400-acre) sprawl is still the UK’s largest construction site more than a decade after the plan for Britain’s nuclear renaissance first emerged.
It will be at least another six years before Hinkley Point C, the first nuclear plant to be built in the UK since 1995, begins generating 7% of the nation’s electricity.
The price tag is expected to exceed £20bn, almost double that suggested in 2008 by EDF Energy, which is spearheading the project alongside a Chinese project partner.
At the time, EDF Energy’s chief executive, Vincent de Rivaz, said the mega-project would power millions of homes by late 2017. He pegged the cost at £45 for every megawatt-hour.
De Rivaz retired a decade later, but the promised switch-on moment remains distant. Delays have been blamed on protracted Whitehall wrangling over the project’s eye-watering costs: the price per megawatt-hour has since more than doubled.
Still, this summer workers carried out the UK’s largest concrete pour to complete the base of the first reactor. Simone Rossi, EDF Energy’s incumbent chief, said the milestone was “good news for anyone concerned about the climate change crisis”.
“Its reliable, low-carbon power will be essential for a future with no unabated coal and gas and a large expansion of renewable power,” he said.
The cost concerns have proved more difficult for executives and ministers to address.
The National Audit Office condemned the government’s deal to support the Hinkley Point project through consumer energy bills in a damning report, which accused ministers of putting households on the hook for a “risky and expensive” project with “uncertain strategic and economic benefits”.
Hinkley Point will add between £10 and £15 a year to the average energy bill for 35 years, making it one of the most expensive energy projects undertaken.
Under EDF Energy’s contract with the government, the French state-backed energy giant will earn at least £92.50 for every megawatt-hour produced at Hinkley Point for 35 years by charging households an extra levy on top of the market price for power.
The average electricity price on the UK’s wholesale electricity market was between £55 and £65 per megawatt-hour last year.
The dramatic collapse in the cost of wind, solar and battery technologies has made nuclear power even harder to swallow.
Despite its detractors, Hinkley Point has soldiered on because concerns over the project’s costs, although considerable, are still smaller than the concerns over the UK’s future energy supplies.
The project was first mooted under Tony Blair’s Labour government as an answer to the UK’s looming energy supply gap after years of underinvestment in the UK’s fleet of power plants.
The nuclear mantle was taken up in the coalition years by the Liberal Democrat energy secretary Ed Davey, before it was given the green light by the Conservative government.
Andrew Stephenson, the minister in charge of nuclear, said Hinkley was “trial to meeting our ambitious target of net zero emissions by 2050”.
Nuclear power is controversial among environmentalists, many of whom do not consider the uranium-fuelled energy to be a sustainable option. But according to the government’s official climate advisers new nuclear reactors are needed.
The Committee on Climate Change expects renewable energy to play a major role filling the gap in energy supplies. Offshore wind will increase tenfold to help meet its 2050 target to reduce emissions to net zero, and the climate watchdog has called for onshore wind and solar to play a far larger role too.
But the advisers predict that at least two new nuclear reactors, in addition to Hinkley Point, will be required to help the UK meet its climate goals.
The verdict means households are likely to be called on to stump up for EDF Energy’s follow-on project at the Sizewell site in Suffolk. It also leaves the door open for a resurrection of plans to build reactors in north Wales, and possibly a Chinese-led nuclear project in Bradwell in Essex too.
Hinkley in numbers
• 9,000 cubic metres – the largest pour of concrete ever in the UK took place at the Hinkley Point site to complete the base of the first reactor. That’s the volume of almost four Olympic swimming pools.
• 250 metres – maximum height of the world’s biggest crane, assembled on site after being delivered by 280 trucks.
• 5,000 tonnes – weight of the Welsh steel used to reinforce the base of the first reactor.
• 430 acres – site area, equivalent to about 250 football pitches.
• 30% – the nuclear industry is aiming to reduce the cost of new projects by almost a third by 2030.