Environment

Clip-on wind turbine aims to supplement solar panels

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The primary niche is to clip the generator to the top of existing solar panels in large arrays
The device is a narrow-profile Savonius style wind generator. http://www.indiegogo.com/projects/new-wind-turbine
Ring envisions the generator distributed on the top of existing infrastructure such as pipelines
Ring sees urban light poles as an excellent opportunity
The primary niche is to clip the generator to the top of existing solar panels in large arrays
Cleantec's Michael Ring and business development lead Samuel Zimmerer
The primary niche is to clip the generator to the top of existing solar panels in large arrays
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Crowdfunding has come to the small wind generation field with an Indiegogo campaign intended for an interesting target niche: a small wind generator designed to be clipped onto solar panels. According to its pitch, Cleantec Wind has not only created a prototype, but calculated possible energy returns, targeted a price point and lined up suppliers for initial deliveries and has turned to Indeigogo to get his small startup off the launch pad.

Cleantec's idea is to add lightweight narrow-profile wind generators to the top edge of solar panels. This would put the wind generators a few feet above the ground and in the very turbulent air that will exist in a hot solar array with wind blowing across it. This is an interesting proposal. The solar panels already generate electricity and are already tied into the grid for that purpose. (However, solar farms are engineered for the weight of the panels, the shadows that the panels cast and the output of the solar farms, so the prospect of strapping on a wind generator poses some challenges.)

Another interesting element is the Indiegogo campaign itself. Cleantec has created a range of low-end to high-end rewards for contributions, including working devices. The company has a simple prototype and renderings which do not reflect what they consider the final product.

The wind generator itself is a fairly standard multi-blade Savonious drag generator, which means its output will likely be lower than Darrieus or tri-blade horizontal-axis wind turbines. That's acceptable if the niche fits the generator and price point is appropriate for the amount of energy produced, but we wonder if a Darrieus generator would be a better fit. Both Savonius and Darrieus wind generators have axes parallel to the blades and are typically referred to as vertical-axis wind turbines. The difference is that a Savonius generator uses drag only to capture energy from the wind and has greater upwind drag on the opposite side, while Darrieus blades typically have an aerodynamic component for added speed, lower upwind drag and hence greater generative capacity. Textbooks since the '70s have included standard graphs of power curves for these types of devices.

The generator is claimed to produce 2000 W output, greater than a typical solar panel it might be attached to. At present, any test data or independent testing of the prototype that might have been used to validate the 2000 W is not publicly available from the company's website or the Indiegogo campaign site, though Cleantec's intent is to make it more efficient with such things as curved blades to catch wind from more angles, magnets to reduce resistance to lower start speed and high-efficiency bearings. Such optimizations are familiar on small wind generators like this, and have not historically proven to be economically justifiable when full lifecycle cost of electricity calculations are done. There are many of these types of devices that possibly could be retrofitted for the niche at lower cost via an OEM model rather than creating a new one from scratch, and this might be a direction Ring could choose to go if the engineering difficulties start to mount.

Though the proposed device may not be perfect, Cleantec's suggested an interesting niche for small-scale distributed wind, potentially increasing the output of solar farms in the day and yielding generation at night.

Source: Indiegogo

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18 comments
Dekarate
Just a little more dangerous than the guys at Mythbusters. Looks like a little back of the envelope calculation, some quick CAD models, Google search, some what-if thoughts and presto - 'ready to rock' in their own words. No prototype, no testing, no thought of how the induced torque/momentum on the panels, etc. will be problematic. Cost points are speculated with no backing based on a bill-of-material for yet to be determined components. But hey, there are enough folks out there to buy into the big vision of it's easy, cheap and good for the Earth, that they may find some backing.
Guy Macher
2000 watt hours, maybe. Inefficient design (tri-blades are best), poor placement (low to ground), and not capable of turning into the wind.
Another crowdsourcing boondoggle.
BigGoofyGuy
I think it would be good for when there is little or no sun light but the wind is still present. As mentioned, it would be also good at night time.
jvnn
Well, I would dispute the 2000Watt output number.
Looking at the photo and using standard panel width of 3.5 feet, I estimate the blade portion of the unit covers a swept area of 12' X 1' or 1.11 M^2
Using the standard formula for Power available in the wind: 1/2 Air density X Swept area X Wind velocity^2 (all figures in metric) I get: 1.11 m^2 (12' X 1 = 12 sq feet swept area) 8.94 m/s (20MPH) Air density = 1.23 KG/M^3 power = 1/2 X 1.23 X 1.11 X 8.94^2 = 54 Watts
So theoretical maximum is 54 W. Considering this is a drag machine which operates at low efficiency and even the best machines operate at well below 100%... 2000 Watts is pure baloney.
Michael Crumpton
It is hard to imagine this being a better approach than even a small tower with a standard type turbine attached. Savonious rotors are bad for power generation because of their low top speed and mounting them horizontally gets rid of their big advantage that they can accept wind from all directions. This is just a bad idea all around.
Kent Risine
These things are not so hard to invent as long as no regard for real feasibility is given. Even large scale VAWT setups have infinite payback time: they will never pay the initial investment back.
With these things scale is a factor - as in small is less efficient. There is simply no way that these things will ever be financially sensible. And neither ecologically - the power created will simply be minimal.
The idea that a pair could light up street lamps is out of this world. Even if you are not aerodynamics specialist do a little research - you can get in the right ballpark quite easily.
Jay Finke
I wish I would have thought of that, that's a great idea, on a existing platform. that and it would keep the birds off the cells.
Fritz Menzel
Gotta love Ring's idea of mounting them "on existing infrastructure such as pipelines" (see caption on second image). Oh, the irony.
But seriously, the streetlamp application would work with LEDs.
jeronimo
More horse poop from CAD savvy young minds that haven't a clue of the physics behind their fiction.
Ozuzi
The idea has potential in places where the wind often comes from a similar direction to the the sun (north here). The biggest problem I had with my solar powered house was when it was cloudy for a couple of weeks, and something like this would have helped. As mentioned, the wiring is already there which is a good thing for losses