SMALL WIND GETS BIGGER

Bringing Wind Turbines to Ordinary Rooftops
Anne Eisenberg, February 14, 2009 (NY Times)

"Wind turbines typically spin from tall towers on hills and plains. But in these green times, some companies hope smaller turbines will soon rise above a more domestic spot: homes and garages.

"The rooftop turbines send the electricity they generate straight on to the home’s circuit box. Then owners in a suitably wind-swept location can watch the needle on their electricity meter turn backward…reducing their utility bills while using a renewable resource."

The Swift turbine (click to enlarge)

"One new model, the Swift Wind Turbine, is designed to do its job quietly…The turbine costs $10,000 to $12,000 including installation…When the wind is blowing briskly at 30 miles an hour or more, it will generate 1.5 kilowatts of electrical power…Enough, for instance, to run fifteen 100-watt light bulbs…

"Residents may measure wind speed with an anemometer…The Swift turbine starts contributing electricity when the wind blows at eight miles an hour; as the wind speed increases, so does turbine output…Over a year, the energy output in windy locations should be roughly 2,000 kilowatt hours…electricity costs would be reduced by about 18 percent.

"Turbines must be placed well above the roof to benefit from wind energy…For a two-story building, for instance, the turbine should be at least 15 feet above the roof…"

The Energy Ball (click to enlarge)

"The American Wind Energy Association, a trade group in Washington, recommends placing the turbine at least 30 feet above anything in a 500-foot radius, said Ron Stimmel, a specialist in small wind turbines…

"State and federal incentives will whittle down the price tag for many…about half the states have some sort of incentive…

"Another small wind turbine for residences is the Energy Ball…The Energy Ball is shaped like an eggbeater placed sideways, so that its blades turn around a horizontal axis. One model, the V100, will cost $10,000 to $11,000 installed…and will provide a maximum of 500 watts. One way to mount it might be on a cupola…"