Wind power is derived from solar power: Uneven heating of the earth' s surface by the sun causes uneven pressures in neighboring air masses, and that makes winds blow to restore the equilibrium.
Wind is even more dilute than solar power: The average available wind energy in the US ranges from less than 50 watts per square meter in the Southern Arizona desert to more than 400 W/m2 in southern Wyoming; and several hundred miles off the New England coast it reaches 800 W/m2.
At first sight this seems a lot; with the superficiality of Sierra Club arithmetic one can easily show that the wind blowing over the US has many times the energy needed by its population. In reality, it is not easy to harness a dilute energy source. The biggest windmill ever built (by the West German Ministry of Research, with construction to begin later this year) will have a double blade 333 ft in diameter and will be mounted on a concrete tower 333 ft (100 m) high; but all it will yield is 3 MW¾ when the wind blows. More than 177,000 of these monsters would be needed to provide the US electric capacity even nominally; and many times that number when the necessary reserve due to lack of wind is considered.
But it does not follow that wind power is useless. It is ideally suited for producing small amounts of electric power in inaccessible places, where it would be too expensive to bring in centrally produced power by transmission lines. Wind driven electric generators are also far simpler than solar-electric installations, which are less efficient and more costly (far less efficient and far more costly if they are photovoltaic rather than thermalelectric). A typical application of wind power under such circumstances are windmills providing electric power (for warning lights, etc.) on unmanned offshore oil and gas production platforms. These platforms, incidentally, are also good examples of how difficult it is to foresee everything in theory. Many such platforms off Louisiana and Texas were recently equipped with solar cells, but not for long - the cells are worth thousands of dollars per platform, and most of them have been stolen by fishermen or perhaps by special burglary expeditions. They are being replaced by windmills again; they do not fetch much for thieves and are not worth the risks.
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Vol. 6, No. 6
Newsletter: Access to Energy Newsletter Archive Volume: Volume 6 Issue/No.: Vol. 6, No. 6 Date: February 01, 1979 04:09 PM Title: Energy and dishonor
Copyright © 2004 - Access to Energy Newsletter Archive
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