Instead the government is set to fix the future price of new nuclear electricity, to give investors the certainty of a future income stream.

BBC: Nuclear power: UK will get help to compete, say ministers

In fact, the Committee on Climate Change warns that relying heavily on gas for future electricity supplies would leave households vulnerable to higher bills in the long run as the price of gas on the international market is volatile.

BBC: Gas fracking: Ministers approve shale gas extraction

As construction proceeds, the difference between the price of gas and the price of electricity widens and narrows, giving Duke the opportunity to sell more of the expected output if the price rises or sell output in future years to lock in profits on electricity it has yet to generate.

FORBES: Trading Places