In a recent column in The Enterprise, John Mott-Smith accurately described an alternate form of windmill for capturing wind energy. At least one example of it can be found already in Davis. He reports that this design is quieter than those three-blade propellers we see on wind farms.
An unmentioned feature far more valuable, however, is that this alternate design could avoid most of the bird slaughter currently a byproduct of the three-bladed propellers. Raptors and migrating birds get clobbered by these spinning propellers when their speed makes them least visible to birds in flight.
Mott-Smith describes the alternate: “Think of a cylinder (like a tin can) on a pole, except that the cylinder consists of five equally spaced vertical ‘blades’ ” (we could call them staves or slats). They spin around a vertical axle; when spinning fast, they look like a can rather becoming invisible.
American makers of the “propeller” design would resist changing it now; but the only change needed is the “wind-catcher,” not the mechanism that converts the spinning into electricity. And although the example seen was made in China, American engineers surely can find enough design differences to avoid patent litigation. OK, say it: This one is for the birds. Because it truly is.
Dale M. Heckman