Wind energy advocates often point out that a State, the U.S., or the entire world has enough wind energy to supply all of its electricity needs many times over. Writing in Scientific American, for example, Mark Jacobson and Mark Delucchi note that the world in 2030 is projected to consume 16.9 trillion watts (terawatts, or TW) of power, with about 2.8 TW consumed in the U.S. Total wind flows worldwide generate about 1,700 TW, and accessible wind resources total an estimated 40-85 TW.
Based on such math, the American Wind Energy Association (AWEA) argues, for instance, that Arizona has enough wind to meet 40% of its electricity needs, Michigan wind resources could meet 160% of the State’s electricity needs, and wind in Oklahoma could provide nearly 31 times the State’s electricity needs. Yet despite ratepayer subsidies, special tax breaks, and renewable energy mandates and goals in 37 States, wind supplied 2.2% of total U.S. electric generation in 2010. Why don’t we get lots more of our electricity from this ‘free,’ ‘non-polluting’ ‘renewable’ source?
The chief impediments are wind energy’s inherent drawbacks. First, wind energy is intermittent — at any given time the wind may blow too hard or too soft or not blow at all. Second, wind is non-dispatchable. When Shakespeare’s Owen Glendower boasted, “I can call spirits from the vasty deep,” Henry Hotspur replied: “Why, so can I, or so can any man; but will they come when you do call for them?” Like Glendower’s spirits, the winds answer to no man. The wind is not ours to ‘dispatch’ as electricity demand rises or falls.
There are three main ways of compensating for wind’s intermittency and non-dispatchability — pumped storage (pump water uphill when there’s too much wind relative to demand; let it run downhill and drive turbines when there’s too little wind), natural gas backup generation, and wind dumping (idle the turbines when demand is low). Incorporating those techniques to keep supply in balance with demand adds to the cost of wind electricity, which is typically more costly than coal- and gas-generated electricity even without storage and backup.
What’s more, according to a new Reason Foundation/Independence Institute report, the storage, backup, and idling costs become prohibitive as wind’s share of total generation increases beyond 10-20%. [click to continue…]