Bladeless wind turbine gains patent, now looks for lift

Inventor builds on work of Nikola Tesla to address drawbacks of turbine blades


With debate continuing over this state's recently approved wind farm - 130 turbines to be built in Cape Cod's Nantucket Sound - news arrives of a fledgling alternative to those familiar blade-based structures ... and this new technology traces its roots to a patent issued to Nikola Tesla almost a century ago.

According to a press release from Solar Aero Research:

The (bladeless) turbine is an improvement on a 1913 Tesla patent, specially modified for use in wind generation applications, says inventor Howard J. Fuller, Jr., of the Greenville, N.H.-based not-for-profit scientific research organization.

Solar Aero's completely enclosed model avoids many of the drawbacks of bladed turbines such as noise, radar interference, visual pollution and wildlife injuries -- while retaining relatively high efficiency ratings. With only one rotating component (a turbine/driveshaft/alternator assembly) and no heavily loaded bearings, the turbine is expected to deliver power at a cost comparable to present coal-fired power plants.

Solar Aero contends that the design will allow for easier maintenance and lower maintenance costs, thus making it potentially useful both in remote locations and on city rooftops.

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Risks to wildlife are mitigated by the fact that the unit is screen-enclosed.

While the technology is in its infancy and remains unproven in any real-world setting, the science and environmental blogs are taking notice. From a story on

The bladeless wind turbine is completely enclosed in a relatively small compact unit. Instead of using wind-powered blades to rotate a shaft and generator, the Tesla-inspired design consists of an array of closely spaced, parallel, thin metal disks separated by spacers. When air flows in the spaces between the disks, the spacers are arranged in such a way as to provide inward momentum to the air, causing the disks to move. The disks are connected to a shaft by spokes, so that the rotating disks cause the shaft to rotate as well. As explained in the patent held by Howard Fuller, the turbine design "provides maximum efficiency in converting wind energy to mechanical power."

"The turbine of the present invention has the advantage that it is efficient over a wider range of fluid flow rates, as compared with turbines of the prior art, due to the airfoil-shaped spacers," the patent explains. "This feature makes the present turbine especially useful for generating power from wind, which is inherently random and variable."

Inventor Fuller explained the market opportunities he sees in an interview with

"As we see more and more of the population rising in opposition to the windmills due to noise and wildlife injury concerns, we see more opportunities for our system, so we are... redoubling our efforts to make people aware that there is an alternative.... Our initial market will be residential and small business firms that can effectively use a 10kW baseline unit that can be deployed either on or off-grid. Beyond that, we plan to eventually enter the utility-scale market."

Not everyone is impressed, as several of the comments on the story demonstrate. For example:

My first question is "Under what conditions exactly could the pictured unit generate 10 kw?" It appears to have an intake area of approx. max. 0.5 meter x 0.5 meter = 0.25 sq meter, or 0.025 sq. meters per kw. A modern bladed HAWT, presumably operating near the BETZ limit for the typical wind conditions experienced in the field, can extract 1.5 MW (1500 kw) from a circular disc of diameter 120 meters, area about 10,000 sq meters. That's 10,000/1,500 = 6.6 sq. meters per kw. So how does this unit extract energy from wind 300 times more efficiently? I MIGHT grant the Tesla turbine a capability to operate 2 or 3 x more efficiently than a bladed turbine, but 300 times more? Not very likely. There's some fudging going on somewhere here.

You can read the patent here and see a few drawings.

And Wikipedia has the run-down on the Tesla Turbine patented in 1913.

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