Vermont's mountain winds were harnessed last week to generate electricity for its homes and factories. Slowly, like the movements of an awakening giant, two stainless-steel vanesthe size and shape of a bomber's wingsbegan to rotate on their 100-ft. tower atop bleak Grandpa's Knob (2,000 ft.) near Rutland. Soon the 75-ton rotating unit will begin generating 1,350 horsepower or 1,000 kilowattsenough electricity to light 2,000 homes. Wholly automatic, with its performance recorded by frequent photographs of its dial board, it will produce current about 4,000 hours a year (i.e., about half of the time).
The wind-generated electricity will be turned as a secondary supply into the lines of Central Vermont Public Service Corp. Windless days are no worry, because the machine is built not to replace but to supplement present sources of electricity. When the wind turbine is running full-blast the power company can reduce its consumption of dammed waters, saving them for dry or windless spells. Engineers' big problem, in fact, was to outwit too much wind: a sudden gale could raise the turbine's output in three seconds from 1,000 to 3,000 kilowatts, overloading an unbraked generator. Minimum needed wind speed is 18 m.p.h., and 30 m.p.h. is ideal.
Scientists from M.I.T., Caltech, Stanford, Harvard, the U.S. Weather Bureau took part in the research and design, but the idea man behind the windmill is Palmer Cosslet Putnam, onetime geologist in the Belgian Congo, flyer for Britain in World War I, president (1931) of G. P. Putnam's Sons, Manhattan publishers. "So far as we know," ventures Inventor Putnam, "this is the first attempt to generate alternating current by means of the wind for interconnection with a distribution system."* Engineers are sure that wind-generated electricity will be no costlier than water-generated, may possibly prove cheaper.
Wind studies on other Vermont peaks have already begun, and the New England ranges may someday rival Holland as a land of windmills.
* A few small wind-driven generators, with three-day storage batteries, have been used for private residences, chiefly in England.