Most of this summer saw variable weather and short spells of windy conditions across the UK, followed by a very hot spell at the beginning of September with little to no wind. The consequent sudden changes in wind power output needs flexible backup which can realistically only be provided with Gas power stations. So let’s see how the National Grid coped with providing sufficient power to keep the lights on, and what lessons can be learned.

Power generation by fuel type. Solar is an estimate from University of Sheffield. Wind power is also corrected to include non metered wind farms. (click to expand)
We see just how variable wind power really is with strong output followed by sharp drops to almost negligible output. It is also clear that even if we were to double wind capacity it would still have little affect on such windless periods, which cover the whole of the UK and its off-shore waters. The anti-correlation of wind power with Gas power is perfectly demonstrated below.

Comparison of Gas output to Wind output this summer. They are almost perfectly anti-correlated. Click to expand.
The Net Zero agenda calls for the phasing out of all fossil fuels by 2050, yet as clearly demonstrated, the largest renewable source (Wind) is totally dependent on an equal capacity of gas backup. Nor is it in feasible to store any excess energy on windy days (in batteries) to cover regular “dunkelflautes” simply because the energy storage requirements are astronomical and dangerous (Mtons of TNT)!
If we simply calculate the average net energy produced by different sources then we discover that our few remaining nuclear power stations generated almost the same amount of energy as all UK wind farms combined. (17% as compared to 23%). Gas will always remain our primary source (38%) until we build more large nuclear power stations. All other paths are futile
For the UK to reach net zero simply requires about 5 new EPR (Hinkley C) sized nuclear stations and some realistic localised energy storage to even out Wind and Solar excursions.
Clive, interesting analysis of current power generation, thanks. As to the future, surely a lot more than 5 new EPR’s when you take into account the closure of all but one of the existing nuclear plants by 2026-28 and the huge extra demand from EV’s, heat pumps and everything else requiring electrification?
….and even more if you try to electrify heat and transport. None of this is desirable, achievable or affordable!
Yes you’re right. We probably need about 10 EPRs/ AP1000 power stations. The excess energy at night can charge up a few million EVs !
Well said. An absolutely irrefutable argument.
The need for gas or other flexible thermal plant to cover generation needs is shown by your second graph very clearly. If you build and maintain the reliable grid then you don’t want the complexity, duplication, money wasting of the unreliable one! Given that warming is so inconsequential and arguably beneficial rather than a threat to life, a large portion of it natural and the UK emits next to nothing, I’d build out gas, coal and nuclear generation. I’d secure supplies from domestic and friendly oversees sources and re-industrialise this country to make us independent from China and boost our economy.
Turning up and down gas turbines just to balance wind is also more inefficient causing an increases CO2 emissions and maintenance problems.
Hello Clive ,
The Greens dont have an answer to Wind Drought and never will because they are zealots against nuclear.
In this post truth world we’ll get blackouts first.
Forbin
The root cause of all this nonsense is the Climate Change Act and the idea that renewables are a free lunch. Wind energy rewards the rich at the expense of the poor.
Thank you Clive. As always, an oasis of sanity in a desert of crap.
Thanks Barry. We seem to be drifting into a new age of unreason and dogma !
Clive, why does your Uk power display still show solar output, up here in Yorkshire the sun is long gone as of 19:39 hrs?
It is because the time is Greenwich Meantime rather than UK Summer Time. The reason for this is to keep the same timing throughout the year. The other effect which can explain this is that the software only updates once per hour, so that can explain why it can appear to show solar when it should be dark.
I agree it is a bit confusing but my objective is to compare long term trends over many months/years so I try to keep the daily measurements to a reasonably small number. I sometimes get caught out when Elexon or Univ. Shefield change their format !
The record of recent EPR reactor shows that construction is very slow and expensive (?.?., Olkiluoto 3 and Flamanville). Shall the global temperature be stabilised at an acceptable level, significant emission reduction (?.?., 50%) must be achieved already in 2030. In this perspective, large scale 3. generation nuclear will not play an important role though it may contribute on a longer perspective.
A less expensive and faster path is to apply large scale CCS (CO? capture and storage) on fossil power plants. New fossil fuels plants with CCS can also allow full electrification of transport and house warming (using heat pumps).
CCS is a mature technology with known costs which is not much higher than the present EU ETS price. https://www.iea.org/data-and-statistics/charts/levelised-cost-of-co2-capture-by-sector-and-initial-co2-concentration-2019
Another important feature of CCS is that it can be applied to other industries ?.?., steel, ammonia, cement and waste incineration.
It’s true that the first EPRs were slow to build, partly because of a completely new design with advanced safety features. Olkiluoto is operational making Finland almost Carbon Free.
Westinghouse AP1000s are an equivalent design and also have operational reactors.
When CCS is applied using the latest technologies, what fraction of the energy in the fossil fuel is used in the CCS process?
Very good question Bob !
I doubt whether anyone will tell you the answer.
The record of recent EPR reactor shows that construction is very slow and expensive (?.?., Olkiluoto 3 and Flamanville). Shall the global temperature be stabilised at an acceptable level, significant emission reduction (?.?., 50%) must be achieved already in 2030. In this perspective, large scale 3. generation nuclear will not play an important role though it may contribute on a longer perspective.
A less expensive and faster path is to apply large scale CCS (CO? capture and storage) on fossil power plants. New fossil fuels plants with CCS can also allow full electrification of transport and house warming (using heat pumps).
CCS is a mature technology with known costs which is not much higher than the present EU ETS price. https://www.iea.org/data-and-statistics/charts/levelised-cost-of-co2-capture-by-sector-and-initial-co2-concentration-2019
Another important feature of CCS is that it can be applied to other industries ?.?., steel, ammonia, cement and waste incineration.
Mr. Best, a good day to you. Thanks for your continued work addressing this stuff. I have asked on WUWT (you should see about them posting some of your articles there) why the focus is so singularly aimed at temperature, most particularly air temperature. The oceans are a huge energy battery. If we are warming, cooling, or heaven forbid, doing nothing, the answer is to be found there, not at some weather station 50 miles south of Dehli or Leeds. You have mentioned multiple times the effects of the oceans, and Andy May and Javier Vinos (WUWT folks) have expounded very thoroughly on Meridional Transport (oceans playing a big role).
go nukes
Take care