The news about Hinkley Point is welcome to those of us who believe in the paramount need to avoid climate catastrophe. But the proposed deal isn’t as simple as commentators are suggesting. The full details of the contract are not yet available but the press release gives clues to two unusual features of EdF’s deal. Simply put, these terms are likely to mean that the owner of Hinkley Point is likely to be paid more, perhaps substantially more, than the headline price of £92.50 a megawatt hour. 1) By 2023, when the two new nuclear plants are ready to start humming, the total UK installed capacity of renewable energy is likely to be about 35-40 gigawatts. It may actually be much more if solar PV continues to fall in price. This means that some periods during the months outside winter the UK will be oversupplied with electricity. At those times, Hinkley Point will be required to reduce production. The proposed contract seems to guarantee to pay Hinkley even when it is curtailed in this way. By 2030, it could be stopped from operating perhaps 20% of the time, raising the implied price it is paid when it is working by an equivalent percentage.

2) The headline price will also be inflated by increases in the charges imposed by National Grid to ‘balance’ the electricity network. (‘Balancing’ refers to the process by which the Grid obliges generators either to stop or to start operating in order that electricity supply precisely matches supply). These balancing charges will get larger as the percentage of non-fossil fuel power rises sharply in the next two decades. EdF appears to have obtained an escape clause which exempts it from rises in balancing and grid transmission costs.

Is Hinkley nevertheless good value for money? Probably. But contrast the payment of £92.50 - plus these unspecified extra charges - with the current subsidy for large scale solar PV. PV gets a payment of £68.50 per megawatt hour, to which is added the current price for daytime power of perhaps £40, making £108.50 in total. PV is subsidised for 20 years, nuclear for 35.