There has been a lot of chatter about various vertical axis wind turbines recently, with Maglev Wind Turbine and Quiet Revolution gaining most of the attention.

There are two types of wind capturing devices made. Our photo in the upper left corner of the site, taken at a used windmill dealership on highway 2 in rural Nebraska shows just that, a group of windmills. Windmills are drag based systems. The wind blows, it gets deflected by the pitch of the blades, and at their maximum efficiency the capture around 20% of the kinetic energy in the wind passing through their swept area.

The second type of device is a wind turbine. A turbine uses foils rather than flat drag type blades. The foils generate lift and this causes the turbine to turn, capturing up to 59.3% of the kinetic energy in the wind passing through their swept area.

If a vertical axis turbine looks like part of the architecture of a fancy modern building the chances are its a drag based system that will make little energy unless the wind is very, very strong. These are a statement rather than an investment and/or a power source.

Lift based vertical axis turbines are possible and the Maglev Wind Turbine folks seek to cure the biggest maintenance headache that style of turbine has, the chewing up of bearings and gearboxes due to the turbine mass sitting on top of them. Some of this improvement comes from using helical rather than the straight "eggbeater" type blades which are much smoother in their operation, with the rest coming from levitating the rotating parts. These are promising steps forward, but the only place a vertical axis turbine of any size makes sense is at the top of a sharp ridge, where more power is found at the ground level than high above the surface.

This type of turbine when built on a utility scale is something that will be a niche player and we'll never seen large farms of them in the flat, windy middle of the country.

Oh, and if you see magical advance claims associated with a vertical axis machine look very carefully in the information and you'll find hints of "the man" keeping the company or inventor down. This is a sure tipoff of junk science - if they had something truly revolutionary to offer there would be a massive whirlwind in the form of the very acquisitive Vestas, Siemens, Gamesa, and their fellow manufacturers descending on them to make offers.