The importance of numeracy
I am disappointed to see the - usually interesting - Heresiarch write a profoundly mistaken and, frankly, ignorant post attacking wind power. Now, I don't like dirty hippies any more than the next reactionary, but this is daft:
Why wind? As a giant wind-farm opens in Scotland, it should be obvious that wind power is not the future of energy supply in Britain or anywhere else. Wind-turbines are expensive and inefficient, they ruin the landscape, they are noisy when they work (which isn't very often) and they kill birds. In Taiwan, noise pollution from a wind farm has been held responsible for the death of four hundred goats. The amount of electricity they generate, even now, is negligible. It is said that the vast new Eaglesham Moor plant could potentially power the whole of Glasgow - but that is only when it is operating at full capacity, which even in a country as windy as Scotland is not even half the time.
As David MacKay would say, what we need is fewer adjectives and more numbers. Let's find them:
(i) "Oh noes, teh poor birdies!" MacKay [Without Hot Air, p63-64] notes that in Denmark, where wind generates 9% [!] of the electricity, 30 thousand birds a year are killed by wind turbines - but 1,000,000 are killed by cars! In the UK, a remarkable 55 million birds are killed by cats, and a similar number by flying into windows. If you are concerned about windmills, you must be distraught about cars, cats and windows! Unless, of course, the bird loving is just window dressing.
(ii) "but the property values by which I mean the integrity of the landscape" Didcott power-station used to have an annual open day (this was something of a holiday treat). I used to love it, being in awe of such a mighty chunk of engineering - but I don't think you could call it "landscape-enhancing". Other things you couldn't call it were "cheap" or - Carnot cycles being what they are - "efficient".
(iii) "Which isn't often" We'll have a go at quantifing this in a bit, when we discuss the failings of James Lovelock.
(iv) The utterly surreal: "In Taiwan, noise pollution from a wind farm has been held responsible for the death of four hundred goats." Well, call me Dr. Picky, but I going to be politely sceptical about this remarkable claim. Martin at the Lay Scientist feels the same way, and is prepared to bet no fewer than two goats that the wind farms are innocent of the charge of goaticide.
(v) "The amount of electricity they generate, even now, is negligible." Albeit not as negligible as the amount of electricity now generated by the Heresiarch's chosen alternatives of tidal power and "tapping into the jet stream of the upper atmosphere"[sic].
(vi) A statement that speaks for itself: " Geothermal energy may be even better. This taps directly into the inexhaustible energy of the earth itself, and (technicalities aside) consists of little more than a hole in the ground. It has almost no environmental costs." I think it may be time for my long-planned "Introduction to Thermodynamics" series, which will presumably drive the remaining 3 readers of this blog. I think that's the only way I can explain all the problems with this statement, although if anyone else wants to have a go they could start with defining what we mean by hot rocks, where we can drill the hole, what the rate of thermal conduction thru' rock implies for the rate that heat can be extracted, complete with a parable about aquifiers and oil-wells to make concrete the abstract.
Poor MacKay is enlisted in support for Heresiarch's argument:
Even as the new plant opens, plans are announced to expand it still further (although it already covers 55 sq. km), while over in Shetland an even more elaborate wind-power scheme is attracting increasing opposition. A BBCreport quotes Professor David MacKay of Cambridge, who said that a "100-fold increase" in wind farms in Britain would be necessary to achieve the government target of a complete decarbonisation of our electricity supply system by 2030. The only other alternative to carbon generation he mentioned was nuclear power - itself an outdated and non-renewable technology that brings with it its own problems.
Actually, were the Heresiarch to read MacKay's excellent book Without Hot Air - which you can do for free online here - he'd find out that in ALL five scenarios that MacKay sketches out for a decarbonized Britain, wind power makes contributions from 4% (plan N, WHA pages 208-209) to 64% (plan G, WHA page 210). In the book, he discusses desert-based solar power and carbon-captured - "clean"- coal as well as nuclear.
The quotation from Lovelock is puzzling for two reasons: (i) the specific claim that turbines have an efficiency of 17%, which must be a simple misunderstanding, although there are less charitable explanations. Anyone with GCSE Maths can calculate the efficiency for a disk-like turbine as a function of wind-speed , and anyone with either a bit of calculus or EXCEL skilz can show the maximum efficiency of such a turbine is 59%. This is Betz' law, for goodness sake, it's been around for the best part of a century. Now, actual turbines will show a lower efficiency than this, being made of steel rather than algebra, but Mitsubishi quote efficiencies of 40%. Also note that the specific power of the wind increases with the cube of velocity, so you get much more available at higher windspeeds. (Nuclear advocates like Lovelock might also recall that a nuclear power station is just a kettle, albeit a nuclear powered one: it has turbines, too, to generate electricity. Any heat engine is going to be limited by some efficiency - the World Nuclear Association reckons you can get to 50% efficiency using super-critical water in the heat exchanger) (ii) I simply don't get his wider point. The idea that a turbine farm is sold as producing x MW of power, but only actually produce 0.17x MW in nonscence - everyone knows the difference between capacity (the peak power attainable by a turbine) and capacity load (the expectation value of the power, given local average wind speed) - at least, anyone offering opinions about energy policy should. Incidently, the capacity load of a windfarm in the UK of a good site is typically about 30%
(iii) Further, the idea you need to back up every MW of wind-power with fossil fuels is simply erroneous. Hydroelectric batteries, where surplus electricity is used to pump water uphill, and stored as gravitational potential energy, can and are used to even out the supply. As I say, the charitable explanation is that Lovelock - an extremely eminent man with something of a cult following - has not informed himself as well as his admirers might hope.
We finish off with a fact-free smear:
They make their supporters feel morally superior to their opponents, who can be dismissed as selfish Nimbys. The uglier the wind farms are, the more they ruin the environment, the better: for their very unattractiveness draws attention to the sacrifice that they represent. They are Gaia's temples. The clacking of their sails is like a prayer offered up to Nature to forgive our environmental sins. It's mad.Greens may be fanatics, lunatics, anti-technology, cruel to children or bad in bed : but what has this to do with the merits and demerits of wind power? I also think persons with scientific pretentions ought to support remarkable claims - for example, that "the more [wind farms] ruin the the environment", the better Greens like them - with evidence. Also, if you're going to run with "T3h wind-farms r prayer-weel 4 Gaia worshippers" you'd be well advised not to quote so liberally from James Lovelock.
The Yorkshire Ranter has suggested the problem that macho techno types have with wind: it is "gay electricity". It isn't as hot as a decarbonised coal furnace, and it hasn't the appeal of mighty erections piercing the troposphere and riding the gulf stream like a cheap strumpet.