Tag: Wind turbine

Taking wind power to new “heights”

Posted on by Ray in Energy efficiency, Strategic Inflection Points, System effectiveness

Not sure how I found this (I think Reddit technology) but an OffGrid World article on a new wind tower  configuration looks very odd but seems to work up to 6X(?!) better than most others that are deployed today.  The new wind tower is being built by SheerWind.

The tower has what looks to be a set of funnels around the top (checkout the picture) that funnel wind power and vent it downward into a long duct out along the ground.

Inside the ground duct lies a Venturi effect tube section which constricts and speeds up the wind coming in from the top.  After the Venturi effect component lies a small wind turbine power unit.

Bby placing the wind turbine on the ground, it becomes a lot more accessible. Also, the wind turbine blades can be much smaller due to the increase in wind speed. Finally, the tower is not nearly as tall as current wind turbine towers.

Sheerwind says that the new wind tower can generate electricity from wind speeds as little as 2MPH and will generate, on average, 3.14X more electricity from the same wind power as standard turbines do. These statistics are from some field data they published from their testing.

Still, the thing is huge, the down duct exit funnel has a diameter of twice the man standing next to it.

Couple of potential Improvements

Here are a few thoughts that came to me on some improvements to the tower configuration. One thing I noticed in the field results data is that the turbine speed (wind speed?) seems to be somewhat faster in certain directions than others at the same intake funnel wind speed.  From this I would surmise that wind flowing in the direction of the ground duct works better than wind in the opposite direction.

As such, I would suggest that they do away with the long ground duct all together and just place the Venturi valve and the wind turbine somewhere in the down ducting. This would eliminate one curve which should boost effective wind speed at the turbine, at least and should eliminate any direction sensitivity to the turbine speeds.

Below the turbine I would have a sort of reverse funnel with a cone at the bottom of it to  push the air out along the ground in all directions.

Also, as the wind speed ratio (incoming speed to wind speed at turbine) averages out to be a factor of 1.8, I would think a second turbine downstream from the first with perhaps two blades could extract some more useful power from the air stream before it’s dumped  into the atmosphere.

Finally, as wind speed is often different depending on the height off the ground, I might consider lifting or lowering the top of the tower (the funnel section) to supply the optimum wind speed available. You’d need to have the down duct and its support superstructure to be expandable or contractable and you would want to lesson the weight of the flexible part of the top of the tower. You could do this with an array of electronic wind sensors and servo control logic and motors which would take wind speed samples at various heights and cause the servo motors to raise or lower the tower height. But I believe letting the wind power passively move the top up or down would be more effective in the long run and potentially cheaper to boot. How this would work I have no idea.

Also I would be interested to understand the exit wind speed after all the above, there may still be some energy to be gained from the airstream.

Comments?

Photo Credit(s): From SheerWind.com’s Website, © 2014 SheerWind

Coolest solar PV cells around

Posted on by Ray in Energy efficiency, Strategic Inflection Points, Strategy, System effectiveness, Visionary leadershp, Visionary organizations

[Published the post early by mistake, this is a revised version] Read an article the other day on Inhabitat.com about a new solar array design from V3Solar. They are revolutionizing the mechanical configuration of solar PV cells. Their solution has taken a systems level view of the problem and attacked the solar PV issues from multiple angles, literally.

There are at least two problems with today’s flat, static solar PV arrays these days:

  1. Most static solar arrays work great around noon but their efficiency trails off from there supplying very little power at dawn or sundown and less than peak power 2-3 hours before and after local noon. Solar arrays which track the sun can do better but they require additional circuitry and motors to do so.
  2. Solar cells generate more power when sunlight is concentrated, but they can’t handle much heat. As such, most PV arrays are just flat panels behind flat glass or plastic sheets, with no magnification.

V3 solar has solved these and other problems with an ingenious new mechanical design that provides more power per PV cell surface area. Using a cone geometry there is always a portion of the solar PV cells that face the sun.

The other interesting item about V3Solar’s new technology is that it spins. The main advantage this brings is that it automatically cools itself. In the graphic above there is a hard transparent shell that surrounds the cone of solar PV cells. The transparent shell remains stationary while the inner cone with PV cells on it rotates automatically cooling the PV logic. This is all better displayed on their website with their youtube video.

Also, hard to see in graphic above but depicted well in their video is that there are a couple of linear lenses located around the transparent shell used to concentrate the sunlight. This generates even more power from cells while they are temporarily under the lens, but also heats them up. But with the automatic cooling this isn’t a problem anymore.

At the base of the cone a plate with an array of magnets is stationary but acts as a dynamo as the cone above it rotates with it’s own array of electro magnets. This automatically generates AC power and provides magnetic levitation for the rotating cone.

V3Solar has also patented a power pole which mounts multiple spin cells in a tree like configuration, to generate even more power. The pole’s spin cells would be mathematically located so as not to cast a shadow on the other spin cells on the pole.

V3Solar claims that their spin cell which has a footprint of a square meter generates 20X the power of an equivalent amount of flat solar panels (see their website for details). Besides the animation on their website they have a video of a prototype spin cell in operation.

As of September 24th, V3Solar has contracted with a Southern California company to complete the design and engineering of the spin cell. Which means you can’t buy it just yet. But I want one when they come out.

Some suggestions for improvements

  • Smaller cones and larger cones would make sense. Of course standardizing on one size and cone geometry makes it easier to manufacture. But having different sizes say, 1/2 meter square and 2 meter square, would provide some interesting possibilities and more diverse configurations/applications.
  • One would think that the cone geometry should vary for each different parallel or longitudelatitude, e.g., being flatter at the equator and narrower at the poles to gather even more sunlight.
  • V3Solar shows their spin cell cone in a vertical orientation. It would seem to me that there are just as many opportunities for other positions. Perhaps having the cone point directly south (in the northern hemisphere) or north (in southern hemisphere) or even in a horizontal orientation. I was thinking of having a spin cell located on the back of a wind turbine, in a streamlined orientation (with the top of the cone facing the propeller or even a double cone solution. This way you could combine the two forms of renewable energy in one combined unit.
  • Have the spin cells be able to float on the water in a self contained, ocean hardened configuration. Using such devices could power a more sophisticated, advanced functionaling buoy. Also one could now construct a solar power generation facility that floats on the ocean.
  • Other geometries than just a cone come to mind. I suppose the nice part about the cone is that its planar. But other geometric solutions exist that satisfy this constraint. For example, a cylinder would work. But this time the angle of the cylinder spin would be based on the location. Solar efficiency could be easily boosted by just adding more PV cell surface area to the cylinder or connecting multiple cylinders together t form any length necessary. Such cylinders could be used as an outer casing for any pole. Another possibility is a spinning disk that could replace static flat solar panels to boost energy production.

Just brainstorming here but spinning solar cells open up a number of interesting possibilities.

Needless to say, I want one or more for my backyard. And where can I invest?

Comments?

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Image: (c) 2012 V3Solar from their website