Portable Sail-Type Windmill

Portable Sail-Type Windmill ENERGY Wind Power 27-3-39 Robert Green doesn't need a tower for his horizontal windmill. He doesn't need a bunch of gears or blades. He doesn't even need much wind. "It only takes 3 to 5 mph wind to turn it," he says. Green, a retired mechanical engineer, designed his horizontal windmill using collapsible sails instead of blades. Instead of a tower, the sails ride atop a slender pole. As it turns, it transfers power directly to ground level through an internal rod. The external tube serves as both a vertical support and an anchoring point for guy wires. The simple design means it can be erected in a matter of minutes wherever it's needed. Green has used it for pumping water and air on site and has even developed a unique, low-load pump to use with it. "It can be set up by a pond that needs to be aerated or in the center of a flooded field to pump away excess water," says Green. The novel windmill uses four opposing sails on a wheel and spoke framework atop the pole. As each sail moves into the wind, it opens up like the sail of a sailboat, driving the wheel around the pole. As one sail fills, it pulls against cables on an opposing sail, keeping it tightly closed. The closed sail, which resembles a wing on an airplane, also captures the power of the wind. Just as the different amounts of air pressure lift the wing of an airplane, the air moving across the closed sail creates lift. It also drives the wheel. As the wheel turns into the wind, the process is repeated by each pair of sails. "Traditional windmills are drag windmills, while new propeller windmills are lift windmills," explains Green. "This is sort of in between." He hasn't adapted the device for electrical generation. "I am not an electrical engineer, that's not my field," admits Green, though he is confident the design could work if someone had the expertise. Green sees his system first and foremost as a ready form of mechanical energy that can be adapted as needed. He doesn't sell the windmill itself, but does market plans and rotor kits. He offers hardware kits for 24- and 48-in. rotors at $59 and $118 plus shipping. Green reports selling several hundred packages. Many have gone to Asia, India and other lesser developed countries. In the U.S., they have proven most popular in the West and Southwest. "What I am offering is a formula for making this kind of windmill," he says. "They can take it from there and make whatever they want from it." Contact: FARM SHOW Followup, Robert Green, 1222 W. Grand Ave., Chicago, Ill. 60622 (ph 312 226-7584; website: www.greenwindmill.com).

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