EVER BIGGER WIND

For taller wind turbines, generating power is a breeze
Mark Jaffe, December 25, 2011 (Denver Post)

"…[T]he National Renewable Energy Laboratory in Golden had to redo its wind maps…as wind-turbine towers get taller and blades get longer…[T]he industry standard…[was 50 meters and] is now 80 meters…

"…[A]s the towers have grown from 164 feet to 262 feet, they have edged into the reaches where the winds are stronger and more sustained…At 80 meters above ground level, the wind speeds across a large portion of [Colorado’s] Eastern Plains and Front Range [have gone from 7.4 meters to 8.4 meters a second to] between 8.5 meters and 10 meters a second…[For Indiana]…80-meter towers and technology has meant the difference between not having an economical wind source and having one…"

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"…The new technology combined with the steadier winds are driving down the costs of wind generation, according to economic analyses…A California Energy Commission analysis estimated that a 0.5 meter increase in wind speed — raising the resource from "good" to "excellent" — would cut 1.2 cents off the cost of electricity from a new wind farm to 10.8 cents a kilowatt-hour…In a U.S. Energy Information Administration study, the difference between a top wind resource and a poor one is more than 3 cents a kilowatt-hour, with the best resource producing wind at 8.1 cents a kilowatt-hour.

"It isn't just that the taller towers and bigger blades capture more wind at 80 meters, it is that they can also turn more of the time…Electricity from coal and gas is cheaper because the sources can run 70 percent to 90 percent of the time — this is called the capacity factor…The capacity factor for wind farms has been around 30 percent…[Some wind project] capacity factors [are now up] to 50 percent…[and] wind power has become more marketable…"