Update on the MagWind Levitated Vertical Wind Turbine
Ok, let's take another approach. Mag-Wind says its wind turbine will produce 5 kW at a rated speed of 28 mph (12.5 m/s). To produce that much power at that wind speed it would need to be 281% efficient! Yee ha. That's some windmill. Modern wind turbines, at best, can deliver 40% of the energy in the wind at any specific wind speed. This turbine has a specific rotor loading of 3,360 W/m2 of rotor area. Let's compare that to the over rated AirX. The AirX is somewhat smaller so we won't compare actual production, just rotor loading. Remember, the AirX doesn't even deliver what is promised. The specific rotor load for the AirX is about 400 W/m2. The Mag-Wind claims to produce from its rotor almost ten times more power than the AirX which can't even meet its performance claims. Ouch. I've never seen such outlandish claims before-and I've seen a lot of them.
Link: Wind-Works.org
Via TreeHugger
1 Posted 2007-02-05 23:04:21 by Chris (becky@nt.net)
Well without trying a magwind to verify claims, sounds like someone just wants to sound smart.
im sure mag lev trains, HV engines and even gas savers all have !smart! people trying to prove they dont work but they do.
ps just that fact that it still produces power in high winds that would normally break or stop any other wind generator from producing power must mean something.
prop or turbine... sounds like only a pilot would know...
2 Posted 2007-02-07 14:33:43 by keivn houston (househacker.com@urly-bird.com)
From the original post: "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."
Perhaps the fact that the roof of the house funnels wind into the rotor, means that all of your calculations that depend on area are off.
Remember: according to standard aerodynamic equations, bumblebees can't fly.
3 Posted 2007-02-20 12:00:53 by EM
Actually, according to standard aerodynamic equations and models, it is well understood how bumbleebees fly. Please stop spreading inaccurate myths found in 'inspirational' emails.
One (of many) source:
http://www.news.cornell.edu/releases/March00/APS_Wang.hrs.html
4 Posted 2007-09-19 16:06:47 by squirepuck
Well, on this subject, I work for an "alternative" energy company that was going to sell and install these.
The technical data was all very interesting. But the problem is that they haven't been able to stand up to wind tunnel testing for safety.
A 7 foot metal dart flying through the air isn't my idea of fun. But if they get that licked, it will re-energize the Alt-power market.
5 Posted 2007-12-11 21:38:53 by kwinsdins
It's really unfortunate how much trash talk goes on in the renewable/sustainable energy world. The idea that the roof "funnels" wind into the turbine is silly: unless the wind is blowing just so, and the house is designed just so, and then, how is it THEY are able to say just how much the roof helps? No, it's just ridiculous, wind turbines are rated at a certain wind speed. You can't say "here's how it functions at 20 m/s" and then say "I mean, when you boost it up to 60 m/s with a funnel-shaped roof facing into the (unidirectional?) wind". I can only hope a LOT of people get smarter about reading this crap, or we'll never hone in on the actually effective technologies that are being developed...
kw
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