The British government has just published its energy white paper Powering our Net Zero Future. In his introduction to the paper Secretary of State for Business Energy and Industrial Strategy Alok Sharma pledges to building 40GW of offshore wind by 2030: "enough to power every home in the UK", and talks about shifting from gas to electricity for home heating. On nuclear energy the paper says merely that it aims "to bring at least one large-scale nuclear project to the point of Final Investment Decision by the end of this Parliament, subject to clear value for money and all relevant approvals" and that "retiring capacity will need to be replaced to keep pace with existing levels of demand". However its "illustrative 2050 mixes" envisage a doubling to tripling of nuclear capacity compared to the current fleet:
The graphic shows figures in "TWh" - actually TeraWatt-hours per year. This is a convenient measure for bean-counters who can translate it into prices and costs (a TWh is a million 1kWh "Units" of electricity for which we consumers pay about 15p each) but it doesn't relate easily to the figures we're interested in such as 40GW of offshore wind or 3.2GW power stations like Hinkley Point C. A Terawatt-hour per year is 1,000 Gigawatt-hours per year which is just a Gigawatt times the number of hours in a year: 8,760 — so 1 TWh/y = 0.876 GW. So here for convenience is the same graphic with a scale in GW:
Note that these figures are average amounts of power actually generated. Real world power plants don't generate their full power 24*7. Nuclear power plants have to be shut down for refuelling, inspection and maintenance every year or two, whilst the output of wind and solar varies between their full, "nameplate", capacities, and zero, depending on the state of the sun / wind. The average output (known as "capacity factor") of nuclear plants can be over 90%, but for offshore wind the figure is around 40% and for onshore around 30%. Solar in the UK has a capacity factor of around 10%.
So to get the 50GW or so of renewable power illustrated would require between 125GW of installed, "nameplate", capacity if it were all offshore wind, and 500GW if it were all solar.
Note that these are just illustrations of possible mixes; the BEIS modelled "almost 7,000 different electricity mixes in 2050, for two different levels of demand and flexibility, and 27 different technology cost combinations" producing "a dataset comprising of over 700,000 unique scenarios, allowing us to identify common features of a low emissions, low-cost electricity system". More details of their analysis are in their "Modelling 2050: Electricity System Analysis". This finds that:
Their model assumes "plausible 2050 capacity ranges for those low-carbon technologies that are deployable at scale":
|Gas CCUS||2 GW||30 GW|
|Offshore Wind||40 GW||120 GW|
|Onshore Wind||15 GW||60 GW|
|Solar||15 GW||120 GW|
|Nuclear||5 GW||40 GW|
The most noticeable feature of the "illustrative 2050 mixes" graphic is the huge proportion of renewables (shown in green) - around 50GW. As noted in the table above these comprise onshore and offshore wind, and solar: the Department is still evaluating the role of Biomass and does not include it in their current models. Nor are wave, tidal or other renewable sources considered: the models explicitly consider only technologies currently capable of being deployed at large scale.
With such a high proportion of intermittent renewables it would be interesting to know how the BEIS model would cope with conditions such as those experienced in the UK in first week of December 2020 when, despite temperatures not being particularly cold, the lack of wind (and of course solar, at night) led to coal-fired power being brought online to make up a shortfall in supply.
(Graphics from GridWatch)
A key finding from the BEIS models is that for the most ambitious degrees of decarbonisation - a carbon intensity of electricity of 5gCO2/KW or less - the lowest cost solutions require:
|nuclear||gas CCUS||total nuclear + gas CCUS|
|with hydrogen||15 - 30 GW||15 - 30 GW||35 GW|
|without hydrogen||20 - 40 GW||15 - 30 GW||50 GW|
Although in the BEIS models nuclear and gas with CCUS are more or less interchangeable there are good reasons to prefer nuclear:
Let us therefore look at the higher end of the ranges for nuclear capacity - 30 GW if hydrogen is available, 40 GW without hydrogen. How might this be achieved?
Our current nuclear fleet has a total capacity of 9GW. Most of our power stations are British-designed Advanced Gas-cooled Reactors (AGRs) which are coming to the end of their lives and will all be retired over the next decade, by 2030. We also have one Pressurised Water Reactor (PWR) at Sizewell B. This is licensed until 2035 but EDF, the plant owner, has expressed the intention of applying for a 20 year lifetime extension to 2055. (This is quite normal for PWRs which have, over the decades during which they have been in service across the world, proven to be reliable, safe, and long-lived.)
We are currently building only one new nuclear power station, the 3.2GW twin EPR at Hinkley Point C. As our AGRs retire our nuclear capacity will drop by half:
If Sizewell C - another twin EPR - is approved and comes online in the early 2030s our overall capacity will still be lower than at present:
Assuming retirement of Sizewell B in 2035
If Sizewell B is granted a lifetime extension to 2055
Bradwell B, where a consortium comprising China General Nuclear and EDF want to build a CGN-designed HPR1000 reactor, could add another 2.3GW, taking us to just under 10GW, a modest increase on current capacity:
There are outline plans to build another single 1.6GW EPR at Moorside. This gives us a little more capacity:
What about the Rolls-Royce consortium's 400MW SMR, which should be available towards the end of the decade? The plans for Moorside include some of these. If we assume one is brought online in 2029 and a further 3, one every couple of years, that takes us to 13GW:
This is the extent of current, even outline, plans. It leaves us well short of even the minimum capacity we need to fulfil ambitious but economical mitigation plans in the BEIS model. What if we had more ambitious plans for our fleet? Suppose we were to build 2 EPR reactors instead of one at Moorside and keep on building EPRs, completing them at a rate of one new twin reactor station (like HPC and SZC) every five years. This takes us to 20GW; the minimum capacity we need without hydrogen, a little more than the minimum with it:
If, after Bradwell B, we build further HPR1000 stations, completing a twin reactor station every ten years, and also continue building Rolls Royce SMRs every 2 years, we get to over 31GW by 2050:
Is this too ambitious? Are the assumptions made here, about three new types of reactor to be built in the UK, where we haven't built a nuclear power station since the last millenium, realistic?
A major assumption is that we can build new twin-EPR power stations, pretty much a carbon copy of Hinkley Point C and the proposed Sizewell C, starting a new one every five years, and that each will take around 10 years to build. Given the horrendous delays that have plagued the first two EPRs to be started, at Olkiluoto in Finland and Flamanville in France, this might seem delusionally optimistic. However since those two projects started, two EPRs have been started and completed, now up and running, at Taishan in China, taking about 10 years to build. They were a joint venture between China General Nuclear and EDF, who are also in partnerhip in the HPC project. Both parties have an interest in getting the project completed and bringing in revenue as quickly as possible, and experience in the successful construction of the earlier project.
Another assumption concerns the proposed Bradwell B twin-HPR1000 power station, and others using these reactors. The HPR1000 (also known as "Hualong One") is based on mature designs which have been developed and used for several decades in China, which themselves are based on a proven French design derived from a design by Westinghouse. Unlike the EPR it doesn't have radical and possibly problematic new features. China General Nuclear is keen to build one in the UK in order to gain approval from a respected nuclear regulatory authority in a Western country in order to gain world-wide sales. As such it has an interest in carrying out a swift, trouble-free build. CGN would doubtless be happy to have several more built in the UK. I have assumed the same time to build as EPRs, but actually the first reactor of this type, at Fuqing in China, has just been completed in 5 years.
There are no examples of this reactor design that have yet been built. However it is a Pressurised Water Reactor and Rolls Royce have been building PWRs for submarines and aircraft carriers for decades so they have the technical capabilities. The contribution of these reactors to the overall plan is relatively minor.
The UK has nuclear power stations at Dungeness, Hartlepool, Heysham, Hunterston, and Torness which are to be decommissioned and for which new power stations are not currently planned, plus sites such as Wylfa for which there were plans for new power stations. It seems likely that sites for as many new power stations as we could realistically build in the next 30 years should not be a hindrance to a reasonably ambitious new nuclear building programme.
Yes. Over a period of 20 years France built around 60 reactors giving about 60 GW of nuclear power, starting from practically nothing. They did this in response to the threat of having to pay significantly more for their energy after the oil price shocks of the early 1970s. They now earn several billion Euros per year in electricity exports.
Over a similar period Sweden also built a nuclear fleet which, whilst smaller in size than the French, added capacity at an even faster rate per capita of their population.
Far from being overly ambitious, the nuclear building scheme outlined above is comfortably modest compared to what can be achieved by governments with a clear vision and plan for what they want and need to achieve.
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