Homemade generator harvests wind

When the electric meter — or meters, there are actually two of them — spins at the Shannon Bowman home northeast of Sawyer, it could mean either that he’s buying electric power or he’s selling it.
A homemade wind generator, standing 80 feet tall, with rotors measuring 18 feet in diameter harnesses the Kansas wind and reduces the family’s electric bill by about $57.50 a month, Bowman estimates. An initial investment of $7,000 should pay for itself in 10 years.
He bought plans for the Breezy 5.5 from Prairie Turbines in Derby in July of 2007 and hooked up to Ninnescah REC a year later. Materials include a three-phase motor, blades made of 2 x 12 lumber, parts from an old combine and parts from an irrigation system. It is anchored in concrete, but can be tipped down with a winch so he can service the motor from a stepladder. Once some initial bugs, including too-long rotor blades — “I was trying to be too aggressive,” he said — were worked out, yearly servicing should keep the turbine in good condition. He shut the system down during the heavy snowstorm last March, but otherwise has let it run even in high winds.
It’s an asynchronous induction generator, meaning that it does not require batteries nor an inverter, like many small windmills. It hooks directly into a 30 amp breaker, like plugging in an appliance, Bowman explained.
The generator is rated at 5500 watts and will reach capacity when wind speeds are at 30 miles per hour. It will run the lights, freezers and other equipment in the house, but when his wife turns on the electric clothes dryer, the range or air conditioner, Bowman can watch the system change from the meter registering excess power sold to the utility company to the one measuring the amount he’s buying. His records indicate an average monthly production of 760 kilowatt hours.
Kansas does not yet have net metering, which relies on only one meter that runs one way for selling and the other way for buying, with the same rate applied to each. In states where that system is in place, the utility can actually owe money to the customer at the end of the month. Bowman buys electrical power for 11 cents per kilowatt hour, but sells his excess for only 4 or 5 cents.
“It’s not a gold mine or an oil well, but it helps,” he said.