Update: please see
this post for an update on the claims of this product. -Sean
If you can't tell by the picture, this is, of course, a
"Magnetically-Levitated Axial Flux Alternator with Programmable Variable Coil Resistance, Vertical Axis Wind Turbine". It's called the Mag-Wind MW1100 and, thanks to some interesting technical maneuvering, promises
1100 kWh/month in a 13 mph average wind. The unit will cost around 3.5 cents/kW or, put another way, ROI will be reached in 3 years for someone with an average monthly electric bill of $300 - which sounds very high; a 6+ year ROI might be more realistic for home use. Nevertheless, the inventors claim the unit is cheaper than solar or horizontal wind turbines while requiring much less space to operate.
The site's page on
roof effect describes how the device can produce as much electricity as it does with such a small footprint:
So, how is it possible to make as much electricity as we do with only a 4-foot sweep? We use the roof of a house or other building to extend our reach and increase the volume of air reaching the sails of our VAWT. This gives us the effect of a larger surface area without actually having a larger vane. The great thing is that every house or other building also has a roof. The roof moves the wind, and that wind has a lot of energy.
The two major factors that determine how much energy is available are the vertical rise of the roof and the pitch, or angle, of the roof. The more rise there is, the more wind will hit it and be moved upward towards the VAWT. This is good. However, the steeper the roof is, the more wind energy will be lost in pressure against the roof and wind moving around the roof and the building as a whole. This is not so good.
A roof with a 10-foot vertical rise and a 30% angle will provide nearly a 200% increase in the amount of wind energy that is available to be turned into electricity. Compared to the same turbine just sitting on a pole, the roof effect increases the power yielded by operation of the wind turbine dramatically.
So, although it might be cost prohibitive for some (most), it might be worth looking into if you live in a fairly windy area, as the faster the average windspeed, the quicker it will be to see significant returns on your investment.
Via
Greengeek.ca
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