Relative greenness makes for vertiginous mathematics

1 April 2008

Renewables are not green

It does not feel quite right to be commenting on an academic paper that I have not read but have only read about. This, nevertheless, daringly, is what I am doing. The paper, by Professor Jesse Ausubel of the Rockefeller University in New York,† allegedly argues that the use of renewables does not enable us to protect the environment by means of associated economies of scale. As quoted in the media, Ausubel declares that renewables are thus not ‘green’.

His criterion is the amount of energy producible per unit land area disturbed by the means of production. You must increase this amount to go greenwards, and, on his calculations, hydroelectricity, biomass fuels, wind turbine generators, solar power systems and the rest are much more destructive of the environment than, say, nuclear power stations.

One cannot argue with his quantitative conclusions without seeing his calculations and assumptions, but one can still be reasonably surprised, qualitatively, at some of his results: at how badly wind power fares, for example. According to one reviewer Ausubel finds that wind farms covering the area of Texas and Louisiana combined would have been needed to meet the USA’s electricity demand in 2005. Ausubel’s assumption of the wind regime necessary for this vast aeolian plantation may or may not truly represent any reality, but his figures for it are real. Missing from the reports I have seen, though possibly not from the original paper, are figures for the agricultural or other productivity of the land between the turbine towers. Have not wind power enthusiasts always boasted that you can farm crops and livestock as well as electricity on the land occupied by a wind farm?

Here are some of Ausubel’s remarks as quoted in reports of his paper.

‘As a Green, one of my credos is “no new structures” but renewables all involve ten times or more stuff per kilowatt as natural gas or nuclear.’

‘Considered in Watts per square meter [sic], nuclear has astronomical advantages over its competitors.’

‘Nuclear energy is green.’

‘Increased use of biomass fuel in any form is criminal. Humans must spare land for nature. Every automobile would require a pasture of 1-2 hectares.’

‘From the environmental point of view the biofuels business is madness.’

Students of English literature will remember that William Shakespeare wrote of comparisons that they are odorous, while John Donne described them as odious. No poet, I should call them sometimes overdone and/or onerous. In energy disputations they can be all four. Comparative energetics is not, after all, an exact science.

Not so fast, professor!

Professor Ausubel’s alleged condemnation of increased use of biomass fuel in any form as ‘criminal’ is surely mistaken. Biomass buffs with whom I enjoy sympathies have never advocated competition between food and fuel uses of ‘bio’ products, nor have they called for diversion of fertile land or waters to fuel farming. Rather do such enthusiasts yearn after the utilisation of poor or otherwise ‘waste’ space to yield biomass products and byproducts that are useful in some way but not necessarily for human nourishment.

There are borderline cases, of course, such as the UK’s first sizeable woodburning power station. Recently advertised as able to supply the needs of 30 000 homes, this generating plant at Wilton, on Teesside, England, is already consuming wood waste to produce electricity for the National Grid: and the responsible company sees export prospects for similar or derivative stations at home and abroad.

Wood ‘waste’ has uses other than fuel ones, and I see no harm in rivalry on the open market for these purposes. This is a grey area well left to businesspeople to pick over. And there is certainly plenty of scope for the beneficial use of the hitherto unquestionably ‘waste’ biomass materials.

Class distinction confounds carbophobes

Many will share my thrill on hearing this bit of news from a principality of the United Kingdom. There, in the famously coal-rich south of Wales (the Prince of which latter is first in line for the British throne), a company called Energybuild is beginning to mine high-quality anthracite. The customers include RWE, a big German utility now established also in the UK electricity supply industry. RWE wants the fuel for its power station at Aberthaw, a plant which generates 1500 MW.

In the South Wales region, that land of coalfields, there should be no nonsense about ‘cleaning out’ the carbon first. The mines to be worked by Energybuild offer coal of the highest attainable rank, which consists almost wholly of carbon.

Colin Cooke, chairman of Energybuild, is reported to have described the venture in glowing terms. Annual production is expected to reach 440 000 tonnes at the end of 2009.

I guess that the complete combustion of this magnificent clean-burning fuel will produce some comparably aristocratic carbon dioxide, commanding the classiest possible sequestration.

†Published last July in International Journal of Nuclear Governance, Economy and Ecology, Interscience Publishers, USA

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