Policy confusion on nuclear and wind

Sizewell B nuclear power station
Sizewell B nuclear power station

In the past three months, John Hutton, the UK government minister in charge of industry, has publicly backed an expansion of both nuclear and of offshore wind. Is this good for the UK’s climate targets? Possibly not.


One issue never gets mentioned. Both wind and nuclear need to operate as many hours as they can. For offshore wind to make sense, operators need to be able to sell the power whenever the wind blows. Similarly, nuclear plants need to be ‘baseload’ and kept running day and night. Other plants, such as gas turbine generators can be turned on and off easily. The majority of their costs are fuel and it doesn’t matter very much if they work for ten hours a day, or twenty. They are a good complement to wind, whereas nuclear is in direct competition.

So Hutton’s support both for 32 gigawatts of wind and for a substantial increase in nuclear generation over and above today’s level is inconsistent. In early mornings, total UK demand for electricity falls to well below 30 gigawatts. Here is the pattern over the last eight days:

During much of this time (early March 2008), winds have been blowing reasonably strongly over the whole of the UK. I believe that offshore wind farms with a rated capacity of 32 gigawatts would have been producing outputs of 20-25 gigawatts much of the time. UK nuclear plants have a total generating capacity of about 10 gigawatts today, although some are out of service for maintenance. So if we simply replaced the ageing existing nuclear stations, we would have too much power for the early mornings without considering any other generating plants. And John Hutton says he wants much more than this.The implication of this is simply not understood. If we encourage large amounts of new nuclear capacity, we are likely to reduce the attraction of offshore wind to the point where it simply doesn’t get built.

A large part of the problem is that the UK is effectively isolated from the Continent’s power grid. In a rational world, we would be exporting the electricity from our vast resources of wind to central Europe. It’s true we do have an interconnection to France and a trickle feed to Ireland, but the capacity of these links is negligible. If we are to get substantial amounts of offshore wind, we need a substantial new power cable around the coast that can collect offshore wind and then take it to where it is needed, in the UK or elsewhere.

Elsewhere in the world, power grids are being reinforced to enable long-distance shipment of energy. This is a vital part of the infrastructure for a world that will use larger and larger amounts of renewable energy. Renewables are often unreliable and almost always intermittent. So we need more connections and more transmission lines to guarantee that when the sun stops shining in Spain, the wind from Denmark provides the power in Madrid. And when neither source is available, we can take electricity from Norwegian hydro plants which can be turned on and off at five seconds’ notice.

But nothing in this government’s plans envisages any substantial upgrading of the UK grid, chunky connections to Europe or the establishment of any large Norwegian-style storage reservoirs for hydro capacity.

Last month the Crown Estate published a fabulously detailed and much admired report on the cost of bringing an offshore cable from the wind farms of Shetland and mainland Scotland to London and on to Europe. The cost is substantial, about £1.7bn, (or about the price of half a nuclear generating plant). Although the UK’s liberalised electricity market provides incentives to build power stations, including nuclear, no one in the industry can see who could possibly build the east-coast offshore transmission line profitably. There is no similar incentive in place to build transmission infrastructure even though the long-term benefits to electricity consumers (and to our climate change problems) would be huge.

This is a huge and palpable flaw in the UK’s electricity market structure. Everybody knows about it, everybody sees it as a problem but nobody can do anything about it without government intervention. But the mantra from John Hutton remains the same: the market will decide.

I think it is true to say that nowhere else in the world does the government assume that a rational portfolio of low-carbon electricity generating stations will evolve without intervention on transmission infrastructure. In this country, the core failing is not the much maligned Renewables Obligation but the inability of the heavily regulated transmission system operator (National Grid) to make substantial investments in upgrading power links and hydro-storage facilities without breaching its obligations to Ofgem. Let me put this as clearly as I can: National Grid would not get permission to build the east-coast link from Ofgem. Without this permission, it can have no guarantee of covering its costs. National Grid is a statutory monopolist, although privately owned. No one else can build large-scale transmission infrastructure in England and Wales. So the offshore power grid won’t get built.

Unless we change this, pushing nuclear means we simply won’t get much more offshore (or onshore) wind. What’s possibly as important, we are also increasing the UK’s vulnerability to power shortages in the second half of the next decade. There are many things we need to alter if we are to get real growth in renewable generation, but the crucial task is to invest heavily in transmission infrastructure now.