Wednesday, 5 December 2012

Lies and statistics

I heard an opponent of wind farms speaking at a meeting recently.  No surprise that I don’t agree with his conclusion; but his arguments were mostly of the sort that I can understand and sympathise with, to do with landscape issues and the view.  Beauty is in the eye of the beholder of course, but landscape issues are an entirely honest basis for opposition.  It’s just that they need to be balanced against the question of how we source our electricity.

However, in the middle of his discourse, he dropped in a statistic.  The areas of mid Wales where wind farms are being built are at such a distance from the National Grid, he claimed, that 30% of the electricity produced is lost before it even gets to the grid.  It reminded me rather of the claim that 78.6% of all statistics used by politicians (including of course that figure of 78.6%) are made up on the spot.
The 30% figure is one often quoted – there are plenty of instances of that or a similar figure to be found on the Internet, but what is the basis for it?  I got involved in a lengthy debate with one of Plaid’s Assembly candidates in another blog post on this very question about two years ago.  He quoted the same figure at me.  His response to my question about the source of the statistic met, initially, with repeated and vehement assertion that the figure was correct and an expectation that I would simply accept it.  Eventually however he admitted that he had no basis whatsoever to justify the use of that figure.
There are losses during transition of course.  The National Grid estimates them at around 2% for high-voltage transmission system and up to another 6% for the lower voltage distribution system, making a total maximum loss of around 8%.  The most usual response of opponents to this is the Mandy Rice Davies rebuttal – “they would say that wouldn’t they?”.  Well, yes, they would; but that isn’t enough to make it untrue.
The higher the voltage, the lower the losses; so at the proposed voltage for the link from the Mid Wales wind farm to the Grid, the loss would probably be in the range of 2 to 6%.  Ironically, the lower voltages preferred by anti-wind campaigners in order to have smaller pylons would actually put that figure closer to the top end of that range that it would otherwise be.  In any event, however, it is still hugely below the 30% suggested.
Apart from my natural aversion to made-up and unjustifiable statistics, does it even matter?  Clearly transporting expensive fossil fuels to the middle of nowhere and then burning them to generate electricity which loses a large proportion of energy before reaching its point of use would be a silly thing to do.  But, even if the loss from wind farms were to be 30%, rather than the more realistic figure of 3-5%, the advantage of wind power is that the fuel is essentially “free” and, for all practical purposes, is unlimited.  So losing part of it en route really isn’t a problem in the way presented.
The 30% figure is not only hopelessly inaccurate; even if it were true it does nothing for the argument in support of which it is being deployed.


David Walters said...

I can go with the argument that the fuel itself is "free". "Unlimited" is a far more thorny matter. "Unlimited" implies constant which is not the case. Therefore "unlimited" equates to lots and lots of wind - if it ever blows.

Aversion to statistics is very healthy.

maen_tramgwydd said...

The way I see it John, is that not only are these things a blot on the landscape of a beautiful country, but that Wales is bearing an unfair share of them (in terms of environmental targets) when compared to our neighbours to the east.

Even worse, is the fact that Wales gets little or no economic benefits from them. The companies that construct, erect, maintain and operate them aren't based in Wales.

The subsidies paid to the operating companies, are partly paid by taxpayers and electricity consumers in Wales, and the profits don't stay in Wales either, which is a triple whammy for our country and its economy which is in a parlous state.

I know you'll disagree, but they're not very efficient either, and only produce a very small percentage of 'green' energy even when they're operating at full capacity, let alone when they're standing still at times of excessive wind or no wind at all.

Consequently, I believe that they're bad news for Wales and its people.

The nearest wind farms are at least ten miles from my home, and are barely visible, and there is no possibility of any being built any closer, as I live in an urban environment, lest you think I have a vested interest in opposing them.

John Dixon said...


"'Unlimited' implies constant" - not to me it doesn't. I doubt that, down here on the planetary surface at any rate, there is any source of electricity generation which is 'constant', but there are some which are - to repeat the phrase I used in the post - 'for all practical purposes' unlimited. It just means that, unlike coal, oil, and gas, wind will never run out.

The extent to which constancy - or lack thereof - is a problem is at the heart of much of the debate about energy policy. In the end, it boils down to questions of probability; some sources of energy have a greater probability of non-availability than others, but there are no non-zero probabilities. Nothing new there; unbeknown to most, the whole Grid system is planned on the basis of compound probabilities.

Aversion to statistics, particularly when they are spouted by politicians in place of facts, is indeed very healthy. Aversion to the facts themselves is rather less so...

G Horton-Jones said...

Transmission losses pdf

Losses are distance related and also subject to air temperature ie cable temperature. Cold equals greater loss also no mention of EMF up to 8ft around 11Kv cable pro rata increase in distance for 33 kv 66kv and up in multiples of 11Kv

John Dixon said...


Any successful economy has to have 'an unfair share' (larger than percentage of population) of things that it can produce to make up for the 'unfair share' (smaller than percentage of population) of those which it cannot. If we want to buy things from elsewhere, we have to sell things as well; and green energy is something for which the demand is only likely to increase. Being able to produce mroe than the country next door is, in that economic context, an advantage not a punishment.

There is a wholly valid question to raise about the environmental price we pay to produce those things which we can sell, and I entirely respect the argument about the value of landscape. It's the one honest argument that I've heard against wind energy, and provided that those who make that argument are prepared to forego the potential economic benefits to Wales of being a net exporter of energy and/or explain what other products we produce in surplus to exchange for those things we need, then we can draw some sensible lines about the alternative scenarios.

I also accept your point that "Wales gets little or no economic benefits from them". I would say, however, that the same is true - to a greater or lesser extent - about much of the economic activity in Wales. The head offices are elsewhere, and the profits are syphoned off. I would say, though, that that's an argument about economic systems and structure rather than about the activity itself. And I suspect that we'd both agree that we need to change the way that benefits from economic activity in Wales are distributed.

"They're not very efficient either". You're right, I don't agree. I think that you are misusing the word 'efficient' in this context. Gas power stations may generate for close to 100% of the time, but extract only around 40% of the useful energy from the fuel they burn. That's serious inefficiency, because (a) the gas is a limited resource, and (b) most of the other 60% is discharged into the environment as waste heat.

If you mean that wind farms only generate around 30% of their maximum nominal capacity, I'd agree with you. But that's a feature of a renewables-based economy using as much 'fuel' as happens to be available at the time, it isn't a measure of 'efficiency'.

John Dixon said...


Those figures indicate a total of between 9 and 13%. Higher than the Grid's own figures, but still well below the 30% quoted by opponents.

Anonymous said...

I don't think maen_tramgwydd's opposition to wind farms is solid.

"but that Wales is bearing an unfair share of them (in terms of environmental targets) when compared to our neighbours to the east."

This though is because Wales' elected governments have chosen to set more ambitious targets than the Government in England. With the exception of large offshore windfarms which aren't Welsh responsibility, Wales has taken its own political decision to host proportionally more farms.

"The subsidies paid to the operating companies, are partly paid by taxpayers and electricity consumers in Wales, and the profits don't stay in Wales either, which is a triple whammy for our country and its economy which is in a parlous state."

But the subsidies are also partly paid by taxpayers in other parts of the state.

I agree that we should have more renewable companies in Wales though. We've missed the trick in the supply chain.

I think there needs to be more understanding that although the infrastructure like the grid, pylons etc is UK responsibility, the wind targets have been set by the Welsh Government, not foisted upon us, and also that the Welsh public generally supports the development of wind energy and renewables, as do at least 3 of the major political parties in Wales (not sure about the Tories).

John Dixon said...


I agree with almost all you say there. Not sure that I can agree, though, with "as do at least 3 of the major political parties in Wales".

Regardless of what their official policies actually say, it seems to me that, in practice, the policy of Plaid and the Lib Dems is to allow their elected members and spokespersons to take whatever stance they think will win them votes (or maybe just not lose them); Labour prefer to remain silent on the issue, by and large, and the Tories are mostly opposed.

Whilst there are some brave individuals in some parties prepared to support the use of wind energy, I see no sign that any of the parties is offering clear support.

Anonymous said...

John, you're right of course. I have known of Plaid and Lib Dem politicians campaign against them. Wind causes such strange reactions. I'm sure a few weeks ago a Tory Minister said onshore wind was over. But it obviously isn't. I'm also sure Glyn Davies is opposed to wind but under his Government they're still going ahead in Powys. Nobody really is taking responsibility for the situation.