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Windmill Tower Goes Up Quick
Roy Hershberger’s windmill goes up fast and comes down fast for maintenance, without even loosening the 8 guy wires. The 90-ft., single mast tower can be raised and lowered in as little as 7 min., according to Hershberger.
  “We had 120 mph winds this summer that took out trees, but left our wind tower standing,” says Hershberger, designer of the unit.
The Wind Energy Tower differs from traditional wind power systems in several ways. Not only does it come standard with an air compressor instead of an electrical generator, it uses airfoils instead of the more common propellers.
The tower needs 9 to 10 mph winds to get started. However, it will continue working at wind speeds as low as 7 mph and doesn’t stop until wind speeds reach between 80 and 100 mph. The three-blade, 18-ft. rotor will reach blade tip speeds of up to 350 mph.
At wind speeds under 8 mph, an independent compression system lets it build speed until start-up torque is reached. At the higher wind speeds, the airfoils automatically slow.
“The compression system vents into the atmosphere until it exceeds 120 rpm’s,” explains Hershberger. “However, that can be adjusted simply by changing pulley sizes. It reaches maximum speed from 20 to 35 mph and about 600 rpm’s. From 50 to 80 mph, the airfoils begin to furl and slow.”
Hershberger says air power can be used with a variety of outlets, including pneumatic shop and household equipment as well as water pumps and fans. He is experimenting with using it on a Freon pump for walk-in coolers and freezers.
“It would be easy to mount a PMA (permanent magnet alternator) or generator on it,” says Hershberger. “The compressor mounts to the sprocket head with four bolts. The airfoils and hub shaft power a pulley that drives the compressor head.”
Lowering the tower to maintain or change pulleys or compressors is easy, even with a stiff side wind. Once in place, the guy wires remain attached, and some remain taut as the tower is lowered and raised.
“When the tower is raised back up, the other guy wires automatically tighten back up,” says Hershberger. “All you have to do is lock and unlock the winch to raise or lower.”
The airfoils are designed to run at half the speed of sound. However, Hershberger notes that during testing the tips at times broke the sound barrier of 768 mph.
“The resulting clap isn’t something you want to produce on a regular basis,” he says. “However, we know the tower can handle those speeds.”
Hershberger’s Wind Energy Tower has a suggested retail price of around $8,000. However, individual distributors may sell it for less. Currently he has four distributors, but is looking for more.
Contact: FARM SHOW Followup, Wind Energy Products, 19307 Echo Ave., Bloomfield, Iowa 52537 (ph 641 722-3948).


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2011 - Volume #35, Issue #6