2009 - Volume #33, Issue #3, Page #20[ Sample Stories From This Issue | List of All Stories In This Issue | Print this story | Read this issue]
"Floating" Windmills Mount On Silos, Barns, Homes
One of the main problems with conventional windmills is excessive vibration. Mag-Wind turbines use magnetic levitation to virtually eliminate vibration, making the units almost totally silent.
"We don't have any vibration with our turbines because the sail floats above the shaft on opposing magnets," explains Johnson.
Another advantage of the design is the placement of the coils on the power-producing alternator, says Minnesota distributor Dave O'Brien (ph 612 701-4730; www.hgwindpower.com). "Mag-Wind units use an axial flux alternator so the coils are around the perimeter," he says. "The rotational velocity required to generate maximum power is only 50 rpm's."
The powder-coated aluminum sails are available in eight different sizes with sails selected for a given area's average wind speeds and turbine size. The curved design maximizes lift as the sail turns into the wind and minimizes drag as it turns away. While height helps, it is sail size that's key to electricity production.
"A 2.5 kW turbine in North Dakota with high wind speeds will require one size sail," explains O'Brien. "The same turbine in lower wind speed areas of Wisconsin will require a larger sail. As you increase sail size in the same wind, you increase power output."
Johnson says Mag-Wind units are specifically designed to be mounted on a roof. Positioned properly, Mag-Wind units take advantage of what Johnson calls "Leading Edge" compression.
"As a wind passes over the edge of a flat roof, there is about a 3-ft. area above the peak where energy is twice what that straight wind is," he says. "On a peaked roof, it can be as much as 3 1/2 times the energy."
This translates into capturing the equivalent of a 20 to 35 mph wind from a 10 mph straight-line wind. Larger Mag-Wind units are being designed for use on city high rises where the compression factor is even greater.
"There is a massive amount of energy there," says Johnson. "High rises can have an 8-fold increase in energy."
Power begins being produced at wind speeds as low as 4 mph with maximum output at 25 mph. Power production continues to a maximum rated speed of 90 mph with low wind sails or 120 mph with high wind sails. When speeds exceed those limits, the mag-lev design allows the control system to use resistance between the magnets to slow the sail without shutting down power production.
Current production models include the 1.5 kW turbine priced at around $15,000, including shipping and installation. A 5 kW turbine is priced at just under $35,000 with shipping and installation, and a 10 kW turbine is priced at just under $65,000 with all costs. With current Federal subsidies, a buyer can reduce those costs by an estimated 30 percent. State subsidies can further reduce the cost of an installation.
Johnson says the company is working on a complementary project. "We're developing an electrolyzer unit for those who want to store excess electricity as hydrogen gas for use in fuel cells or other purposes," he says.
Contact: FARM SHOW Followup, Enviro Energies, 183 South Service Road, Suite 1, Grimsby, Ontario, Canada L3M 4H6 (ph 888 253-7975; fax 905 963-7931; www.enviro-energies.com) or HG Windpower, 2163 Kelly Circle, Shakopee, Minn. 55379 (ph 612 701-4730; fax 952 445-5935; HGWindpower@gmail.com; www.hgwindpower.com).
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