The government has signed a controversial deal to begin building Britain's first new nuclear power plant in a generation.
Hinkley Point C in Somerset will provide up to seven percent of the UK's overall electricity requirement when it comes on line in 2023.
The £16 billion project hinged on the Government guaranteeing EDF, the French-owned company that will build the plant, a minimum energy "strike price" for the future.
Energy Secretary Ed Davey estimates that the deal will save consumers £77 a year by 2030, as well as reducing reliance on the volatile gas market.
ITV News' Economics Editor Richard Edgar reports:
Mr Davey said it was a "historic" day, adding that a new generation of nuclear power stations, alongside other forms of electricity generation, would be a key part of the future energy mix.
"We have to replace nearly 60 percent of our electricity generating capacity in a relatively short space of time. If we rely on gas, that would be too risky for consumers," he said.
Labour said it agrees that nuclear power should be part of the UK's future energy mix, but leader Ed Miliband said the Government must take action on energy price rises.
"We're in the ridiculous position today where we've got the Prime Minister who says that he can fix prices 35 years ahead for the energy companies but he can't freeze prices now for the consumer."
The Government confirmed the strike price would be set at £92.50 per megawatt hour fixed over 35 years - around double the current energy price. This is expected to drop to £89.50 if EDF goes ahead with proposals to build two reactors at Sizewell in Suffolk.
It is this rate that will determine to a large degree whether the plant is good value for money, Richard Edgar said.
"We think it would be good value if [the strike price] was a little higher," Mr Davey said, adding: "I was determined to get them below £90 so I could prove to everybody we had got a good deal."
But energy campaigners fear that today's deal heaps the burden of risk on consumers, who will ultimately pay higher energy bills if the calculations are wrong.
The Prime Minister has said that the deal will create "thousands of jobs" in the UK, as well as "providing long-term, safe and secure supplies of electricity far into the future".
"As we compete in the tough global race, this underlines the confidence there is in Britain and makes clear that we are very much open for business," he added.
EDF said 57 percent of the project's construction value could be spent in the UK, while 25,000 jobs will be created during the construction phase, including 400 apprentices.
A further 900 jobs will become available when the site is operational, EDF said.
The deal was condemned by some environmental groups, who argue that the figures do not stack up when the costs of decommissioning and storing nuclear waste are factored in.
"At the moment we don't know what to do with the nuclear waste and that means we are giving our children and our grandchildren a huge cost to pick up cleaning up after we've finished with this energy," the Green Party's Baroness Jones said.
Greenpeace UK director John Sauven said:
Hinkley Point C will be the first new nuclear power station to be built since Sizewell B, which started generating electricity in 1995.