Author Archives: Robert Wilson

Wind farms and blackouts

“Lack of wind or nuclear problems ‘could wipe out UK’s spare power capacity'”

This is a headline at the Telegraph this week. Lack of wind may cause blackouts. Should we worry about it?

There are of course no numbers in the Telegraph story, or in this rather absurd story in the Guardian that claimed that recent fire at Didcot B power station showed “the intermittency of some renewables is simply not a problem“.

What we really need are numbers, and not badly thought through talking points.

So, can we really rely on wind farms to provide our electricity around the clock?

If you ever tune into BBC1 at 6.28 pm you will know that winds around Britain are not consistent, and that we frequently see calms from north to south. Wind speed of course is not the whole story. The kinetic energy goes up with the cube of wind speed.

The result is that wind farm output often goes close to zero, and this can coincidence with peaks in demand.

Let’s look at the last three years.

Below is a plot of hourly electricity demand versus wind power output in October, November, and December 2011. The black vertical line is the peak in demand; while the red horizontal line is 5% of peak wind farm output. If we are thinking about blackouts, what really matters is the bottom right. The fewer dots there the better.2011In 2011, wind farm output peaked at around 3.2 GW.  However, you can clearly see that wind power output is often very low. It often gets close to 5% of peak wind farm output.

In 2012 things were much worse.  Wind farm output was frequently below 5% of peak output during these months. And, as the bottom right of the figure below shows, wind farm output was below 5% of its peak when demand was more or less at its annual maximum. A repeat of this is 2014 may make things very dicey.2012Things were a bit better in 2013. There were fewer calms that year. However, wind farms could still not be relied upon to provide more than 5% of their peak output. 2013Essentially we do not want many dots near where the black and red lines intersect. In 2013, this was relatively OK. In 2012 it was not.

So, weather dependent, Britain will be blackout free this winter. But please, do not tell me that intermittency of renewables is not a problem.

Note on data

The National Grid provides data for hourly load and wind farm output. To save me time I have taken this from PF Bach’s website.

This article is a very quick back of the envelope piece. I’m currently writing something for the Energy Collective, about the need for back up for wind farms. Hence, I was able to quickly pull these plots from what I had produced for it. That piece will look in detail at data for multiple countries. But questions/suggestions below the line would be welcome, so that I can get the final (more finished) article in good shape.




The risks of nuclear energy

For those who still read my rather defunct blog, I have a new piece over at Energy Collective looking at how the risks of nuclear energy are often exaggerated. In this case I look at a bizarre report often cited by environmental groups. Incredibly this study, which was funded by a German renewable energy lobby group in 2011, claims that the probability of any nuclear power plant being attacked by terrorists each year is once a year.

So, if you remember your rules of probability you can quickly see problems. There are over 400 nuclear power plants on the planet, or more accurately reactors. (I assume the report really means reactors, but the numbers are as bad either way.)

The probability of no nuclear power plants being attacked in a given year is (1-1/1000)^435. This is 65%. In other words the report is claiming there is a 35% chance that a terrorist attack will be carried out on a nuclear power plant somewhere each year. This is obviously nonsense. Yet, we find Friends of the Earth citing this report. In fact they cited it in a recent briefing where they re-iterated their opposition to nuclear energy. This briefing was in response to a review of the evidence into nuclear energy by the Tyndall Centre, which was a decent evidence based review. The Tyndall Centre produced an evidence based section on the external costs of nuclear energy. Sadly Friends of the Earth rejected this in favour of junk. An old story.

Is Owen Paterson correct about the scale of wind farms?

Our estranged former Environment Minister Owen Paterson is at it again, issuing a much trumpeted speech calling for the Climate Change Act to be scrapped. Most of this speech is errant nonsense, as you would expect.  And it would be tiring of me to go through it point by point. So I’ll keep things to the point and discuss a couple of the speech’s half notable claims.

Dubious claims about Combined Heat and Power

Strangely there are things in it than he and some green leaning people would agree with. One is on the need to build combined heat and power plants. Right now we waste huge amounts of heat from power plants. Instead we should re-direct that heat into district heating systems. The numbers speak for themselves. A coal power plant is typically less than 40% efficient. A CHP plant can be 90% efficient. This is an efficiency improvement we should capitalize on.

Convinced? I hope not. For what you have just read is a simple sales trick. CHP stands for Combined Heat and Power, not Power.  Curiously the efficiency of heat generation is not part of the CHP sales pitch. So, let’s strip it down. From a legal point of view you can no longer build a coal power plant in Britain. This leaves us with a 50 or 60% efficient gas power plant as our legal minimum as far as CO2 emissions are concerned.  How efficient is heating? Well, certainly not as low as 50 or 60%. Gas furnaces that pass basic efficiency rules are at least 90 or so percent efficient. So, all in all a gas power plant plus a gas furnace is not really any less efficient than a CHP plant.

On the other hand, you can generate electricity from a wind farm or nuclear power plant. Combine that with a gas furnace and you have much lower CO2 than you get from CHP. Going further, you can install a heat pump in your home, which will outperform a gas furnace. CHP, then, is clearly a snake oil solution to climate change, and should be treated as such. If you want to see the numbers in more depth, read David MacKay’s book.

Paterson’s anti-wind farm case could have been made stronger

Paterson claims the following.

Wind capacity in the EU 27 must rise from 83 GW in 2010 to 984 GW in 2050. It means an increase from 42,000 wind turbines across Europe, to nearly 500,000 wind turbines. This would require a vast acreage of wind turbines that would wall-to-wall carpet Northern Ireland, Wales, Belgium, Holland and Portugal combined.

This is to put it simply something that Paterson (or his ghost writer Matt Ridley) has made up. There are no EU requirements whatsoever to expand wind energy through to 2050. In fact, contrary to what many believe the EU’s 2020 renewable energy target is being met more be expanding bio-energy, and not wind farms. This is clear from the graph below, which I produced for this piece earlier in the year.

BiomassvWindSolarThese are simple quantitative facts, and can be found easily by reading official statistics.

The EU, then, has seen more more of a biomass renaissance than a wind and solar revolution. You may not read about this in the Guardian or the Telegraph, but it is the plain truth.

But Paterson is perhaps correct in key respects. Large parts of Europe have now foolishly ruled out nuclear energy. In fact, it is highly unlikely that the EU will be getting any more energy from nuclear power plants in 2050 than it does today. This is simply because countries such as Germany have ruled it out, and those actions add up. Carbon capture and storage is also on a slow track, and not looking like expanding quickly at all. Though this might change. Solar is also unlikely to get beyond marginal in cloudy high latitude Europe, despite the wishful thinking of the environmental movement. So, EU climate targets in reality look more and more like de-fact wind power targets, whether we realise it or not.

How much land would the EU need to cover in wind farms? Let’s start with final energy consumption.  Accordingly Eurostat the EU’s gross consumption of energy was 1.7 billion tonnes of oil equivalent in 2012. This is approximately 2.3 (TW) terawatts, if we think about it in terms of average power.  2.3 trillion watts is a big number and hard to get your head around. But how much land would be need to supply, say, 1 TW (just under half of current EU consumption) from wind farms?

The power density of wind farms in Europe is not likely to be above 2 watts per square metre on average, and might even be lower.  This means that providing 1 TW from wind farms will require something like 500,000 square kilometres to be covered in wind turbines. The UK is 230,000 square kilometres. So, two UK’s worth of land covered in wind farms. Not exactly “small is beautiful” stuff.


How does this compare with Paterson’s made up scenario?

The combined area of Northern Ireland, Wales, Belgium, Holland and Portugal is almost exactly 200,000 square kilometres.

This is less than half of the area I calculated above.

So, here is a piece of advice to Owen Paterson (or Matt Ridley). Next time you want to make a badly informed attack on wind farms, drop me a line, and I will strengthen it.

This of course is an argument based on mere aesthetics, and aesthetics that on closer inspection are more green than blue. And as Jonathan Meades observed, the correct response to Small Is Beautiful is Big Is Sublime.

Bunkers Brutalism and Bloodymindedness Concrete Poetry – One from MeadesShrine on Vimeo.

I will leave the remainder of Mr. Paterson’s speech for other unfortunate souls.

Writing on Hinkley C

Britain’s first new nuclear power plant in a generation appears to have got passed the final key hurdle, European Commission approval. I’ve written something on the issue over the Energy Collective here.

Hinkley C is in the words of some commentators, the world’s most expensive power plant. But who gains from such language? Offshore wind power developers who offer up electricity at a rate 50% higher than Hinkley C? Onshore wind power developers who offer up electricity at the same rate as Hinkley C? Strangely offering up anti-nuclear arguments that play directly into the hands of opponents of renewable energy is viewed as a sensible strategy by the folk who run organisations such as Greenpeace.  But  perhaps we can all agree with them that £90/MWh is too much to pay for electricity, and welcome a new dash for gas.

When does electricity demand peak?

I frequently hear claims that Germany and other European countries have a peak in electricity demand in the middle of the day, and that solar power can cover this peak. Where this belief comes from I do not know. Certainly, it is true for large parts of America, where electricity demand peaks in the middle of the day in summer when Americans are using their air conditions to excess. Not so in most of Europe where the demand is not in summer, or winter, but on cold winter nights.

To check this I pulled some data together for European countries from the website of PF Bach. Hourly load data for Germany, Britain, Ireland, France, Belgium and Denmark are available. They all show a clear peak at night.

I will show this with two straightforward graphs. The first shows maximum hourly load at each hour of the day throughout the year. To make things clearer I have scaled the graph so that 1 is the maximum for each country.  In other words the hour in the graph with a peak of 1 is when the actual peak occurs.

You can see that all of the peaks occur between 6 and 9 pm in all 6 countries.


What about monthly maximums? Below I’ve plotted the maximum hourly output in each month of the year. As is clear the peak demand occurs in January or December in every country. And the summer peak is much, much lower than the summer peak everywhere.


So, these countries all have demand peaks on Winter nights. This is not likely to change either. Electrification of heating will inevitably make the seasonal peak in heating even more pronounced. An obvious consequence is that solar power cannot replace any fossil fuel capacity in these countries, because of its in ability to produce energy after 5 pm in Winter. That peak will need to be met by something other than solar. This, again, is in contrast to America where solar panels can replace some fossil fuel capacity. Perhaps I will write about this in some more depth in the future.




New stuff

I try to get something new written at least once a month, but it’s a bit of a struggle right now. But I finally have something new available to read. It looks at the receding prospects of keeping CO2 levels below 450 ppm.  Read it here. The concept of “committed emissions” discussed in the piece is one I hope to return to in future.

The Heartland Institute are putting words into my mouth

I enjoy being cited by people I don’t agree with. James Delingpole once said something I wrote demonstrated how corrupt the Green movement was. A curious accusation, I thought.

And today I find myself being cited by the Heartland Institute, which is fine. I believe in free speech, and if people with a political ideology I despise cite me, then so be it. At least it is publicity, and there are clichéd things to be said for publicity.

But what I do not like is having what I write get distorted. Then people might draw the wrong conclusion. And being cited approvingly by the Heartland Institute is not something to shove on your CV.

Here is what they have written about me.

“In his post in the Energy Collective, Robert Wilson, a PhD Student in Mathematical Ecology at the University of Strathclyde, calls Germany’s situation: “more of a coal lock-in than a solar revolution,” as the need for electricity, especially in the cold, grey days of January, requires the steady supply of coal-fueled electricity.”

The implication is clear. Going with renewables requires coal for back up in Germany, and that this is a view I hold is. Total piffle.

The Heartland Institute is either deliberately passing off their own views or are incapable of reading. I cannot rule out both.

However, if the author is too lazy to read through what I have written on the issue and for whatever reason is reading this, I can summarise my views on the issue, views which are public record and are linked to in the article that was distorted.

Germany is not building coal power plants because renewables are useless. They are building them mostly because they are shutting down nuclear power plants. It would have been wiser to build gas power plants, but that would have been less politically correct. These arguments can easily be found at my site on Energy Collective. And Arizona is not Germany. If I observe that growing papayas in Sweden is a bad idea, I would be foolish to conclude that growing papayas in a warmer is a bad idea. Yet, such fatuous logic prevails in energy debates. Suggest solar is a bad idea in cloudy countries and people, a lot of people, will conclude that you think it is a bad idea everywhere. But perhaps I complain too much. I should lower my expectations of public discourse.
Of course organisations as divorced from reality as the Heartland Institute cannot really be expected to do as much as check though what someone has actually written on a subject. To expect that would be rather optimistic, and I am not have a reputation for optimism.