Vail Resorts said Tuesday that it would buy credits for wind power like that generated by the turbines at the Gray County Wind Farm in Kansas. Orlin Wagner/Associated Press
From Scientific American:
One of wind power’s drawbacks is its variability: sometimes the breeze is weak; other times it is strong. To convert the rotation of wind turbines into electricity efficiently, however, generators require a single turning speed. Faster or slower than this “sweet spot” and efficiency falls off fast. To compensate, engineers design turbine hardware to have adjustable blade angles to shed surplus wind energy or to capture more. Wind turbines often also employ a transmission to gear the shaft speed up or down to the sweet spot. But both mechanisms add weight, complexity and cost.
ExRo Technologies in Vancouver is commercializing what should be a better idea: a generator that operates efficiently over a wide speed range. Retrofitted wind turbines could produce as much as 50 percent more power over time, CEO John McDonald states.
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