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Combined Rooftop PV / Wind Turbine / Solar Chimney
  [vote for,

Alright, nothing new and exciting here, except perhaps the packaging.

Photovoltaic flat panel systems generate electricity, people buy them, they install them, and they convert sunlight to electricity, clean and free ( minus initial cost of course, and manufacturing issues, which have all been comming down, getting solved slowly ). Anywhere from 10-30% of the sunlight hitting the roof, that would normally convert to heat, is converted to electricity. But, we still have 70-90% of the sun being converted to heat. How can we use that ?

Solar chimneys are large, transparent glass structures that heat air below a glass cover, and channel it upwards towards a chimney, where wind turbines convert the convection currents to power. Clean, renewable, non polluting ( again, manufacturing aside ) power.

Wind turbines and windmills, suggested locations for home use, if not on a large, ugly ( according to some people ) tower, are at the ridge line or peak of the roof, here, natural wind currents ramp up and there is a magnifying effect, allowing one to extract concentrated wind power at the location where it exists, above the turbulence, collected by the slope of the roof.

My idea, is to combine all these technologies, into 1 system. Flat PV planels installed on the roof, in channels, open at the drip edge, covered with glass, that vent to the peak of the roof, and out through small 2' or 3' (foot) turbines. The turbines would possibly have dual blades, on a dual shaft generator, so wind currents from the back or front of the house could blow through them ( natural wind currents ). The light striking the panels would generate electricity, and heat, which would vent through the peak of the roof, and out the turbines, thereby enhancing their speed and output. The continuous flow of cool air from the drip edge to the peak across the pv panels would help keep them cool.

What do you think ?

headmonkey, Apr 29 2007


       I like it. Cooler PV cells are more efficient.   

       Dual blades and shafts on the generator are possibly a bit clanky. I would be looking at shaping the outlet at the top of the chimney to create a Venturi effect from passing winds, thus sucking more air through. Or using the chimney as a mount for a standard wind gennie.
BunsenHoneydew, May 02 2007

       There are solar chimneys under development even now. I do like the idea of combining the PV with one, that's definitely new. Park a bunch in the desert and really pull in the KW.
elhigh, May 07 2007

       A friend cut a large hole in his roof in College Station TX (near Houston) and the heat from the roof (in the spring) caused the roof that was cut out (4'x4' along the ridge in the center of the house) to float on the air. It was impressive.   

       I suggested that my friend put a fan hooked to a generator inside the copula he was putting over the hole, but he didn't think it would be cost effective (think 30 years ago, then he was right).   

       The copula was effectively a solar chimney. ...   

       In such a case, also putting on the 'solar shingles' would be effective to collect the PV at the same time.   

       I like your thoughts, it could be done today even as a retrofit in the right area.
servant74, Nov 21 2009


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