By Henk Tennekes, Financial Post
Wednesday, March 03, 2010
Wind energy is an engineer’s nightmare. To begin with, the energy density of flowing air is miserably low. Therefore, you need a massive contraption to catch one megawatt at best, and a thousand of these to equal a single gas-or coal-fired power plant.
If you design them for a wind speed of 34 miles per hour, they are useless at wind speeds below 22 mph and extremely dangerous at 44 mph, unless feathered in time. Remember, power is proportional to the cube of the wind speed. Old-fashioned Dutch windmills needed a two-man crew on 12-hour watch, seven days a week, because a runaway windmill first burnt its bearings, then its hardwood gears, then the entire superstructure.