As one who designs and builds wind generators, I\'d doubt this would make as much power as a standard 3 blade design at far less money. The cowling is not a good one. While it would work well for increasing thrust, increasing power in a windgen is another story.
It\'s large size, weight requires more money, tower strength for it\'s output.
The number of blades makes it less eff as each interferes with the next one, making it less eff, more costly. Most eff is 3 blades which is why most use them.

If this is a less efficient design, then why do turbine engines not have three blades? People have been studying them for decades. Both this and a turbine are sub-sonic, so the comparison is valid.

to EnviroDude, external and internal flows, dude

This thing would kill way more birds than a conventional three bladed propeller turbine, and the bird carcasses would clog the mechanism. There\'s a kind of bladeless turbine invented by Nikola Tesla over a hundred years ago that would be less likely to be clogged by bird carcasses.

HenryFarkas - are you talking about a boundary layer Tesla turbine? How would you propose building laminated sheets only millimeters apart yet large enough to extract power from the wind, and still be financially feasible?

Interesting.
Gizmag, can you provide an update to the story (\"...The prototype is expected to be finished by the end of next year or early in 2010\")?

SpiralAirfoil vs FloDesign,

I would like to congradulate FloDesign on a good attempt at extracting energy from the wind, from what I understand, they do come somewhat close to our SpiralAirfoil Design in efficeincy, however their bird is far more complicated and costly then our unique approach. Our test data shows the Spiralairfoil design is over 4.2 : 1 times more efficient then the traditional tri-blades. SpiralAirfoil.com
Thank you
Dan\'l

the design is already being used and proven on small scale systems one of the greatest benefits is the ability to produce power at loser wind speeds. Wind tamer was established in 2002 so check them out http://www.windtamerturbines.com/our-company/ I am in no way affiliated with the company I just find it interesting that this was developed 6 years prior to this article.

Turbofan engines on aircraft are not nearly as efficient on aircraft as turboprop engines ( turbines with propellers), and I expect the same will be true for wind turbines. The smaller blades on the proposed enclosed turbines would probably have to turn at a much higher RPM than the 3-blade turbines. Also it would be diffucult, if not impossible ,to have variable pitch blades to compensate for change in wind speed.There would be many problems associated with enclosed turbines before they would be economically superior to the 3-blade types.

I wish people would stop blaming turbines for bird deaths. Glass covered buildings kill tens of millions of birds a year, just by standing there and looking like sky. Better to work on shrouding buildings so birds miss them, than trying to worry about minimal comparable wind turbine deaths.