Urban wind power inspired by ancient Persia
A new wind-power machine has been inspired by a centuries-old idea: Persian "wind catchers."
Windation Energy Systems, a Menlo Park, Calif.-based start-up, has developed a wind appliance that looks more or less like the modern heating and cooling equipment you see on flat corporate building rooftops.
Windation's appliance looks more like an HVAC machine than a turbine.
(Credit: Windation)There's a 8-by-8-foot frame around a 10-foot-high cylinder. Wind blows in the top and is directed to the bottom where the wind turns a turbine to make up to 5 kilowatts of electricity. A single unit wouldn't generate enough power for an entire office building but could offset a significant portion, the company says.
Windation CEO and founder, Mark Sheikhrezai, who is originally from Iran, said he was inspired by ancient Persian buildings that use air currents and reservoirs of water to cool buildings. Using differences in air pressure, these wind catcher buildings create a steady flow of air without any mechanical devices.
Although Windation's wind appliance does draw air from the top like these buildings, Sheikhrezai said he used his expertise in centrifuges and rotors to manipulate the movement of the wind to generate electricity.
The overall design breaks with that of other small wind turbines, which tend to look a lot more like wind turbines.
Aerovironment's wind turbines, now installed in a few locations, are essentially miniature wind turbines perched on the edges of buildings. Another approach is the vertical axis turbine from Mariah Power.
Sheikhrezai said one of the biggest advantages of Windation's appliance is its shape and ease of installation. Since all moving parts are contained, there isn't potential danger to birds, bats, or people, he noted.
Financially, an investment in a 5-kilowatt appliance, which comes with its own inverter, recoups the installation cost of $45,000 to $50,000 in five to seven years, he said. Depending on the wind or sun resource, a wind machine could deliver a quicker payback than installing a solar array on commercial flat-top roof, he asserted.
The urban wind appliance from Windation is inspired by Persian wind catchers that used naturally occurring air movements and water to cool buildings.
(Credit: Wikipedia)The units will work well with what's called "dirty wind," or gusty, inconsistent wind, Sheikhrezai said.
"Cities like San Francisco, Chicago, Boston, Miami, Cleveland--places you wouldn't think--are all good wind places," he said.
The company is set to install one unit at the Palo Alto Medical Foundation in California and plans to begin manufacturing more units for delivery in February. It then intends to ramp up manufacturing in the following two years. The product will be made in old windmill factory in Nebraska.
Windation, which formed last year, is looking to raise up to $5 million in the next two years and then raise another $20 million for further expansion, Sheikhrezai said.
Small wind turbines are poised for more growth in light of the recently passed economic recovery act. The federal law includes a tax credit of up to $4,000 for small wind turbines, which the mayors of New York City and San Francisco have endorsed for city buildings.
Martin LaMonica is a senior writer for CNET's Green Tech blog. He started at CNET News in 2002, covering IT and Web development. Before that, he was executive editor at IT publication InfoWorld. E-mail Martin.
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I looked on their website. The most expensive device they make is expected to generate 17280 kW hours per year. I guess that's with optimal wind. A kW/h costs 0.08 USD. That means the yearly savings for this device is $1382.40 If the thing costs FIFTY grand then it would take 36 YEARS to recoup the costs. That's if you have optimal wind for 36 years straight. Also, this presumes the device needs no maintenance. Where do they get 5-7 years number from? Is there a tax incentive?
Our patents are pending so they wont show on any patent search, please consult your patent attorney
Here are the pay back data so you can re-check your math
also please understand that we are focused on businesses in the US
this one is for the state of Colorado:
power rating (TWM-5000) 5,000
Average hours wind is on during 24 hrs day 20
days in a year 365
power KWhr generated in a year 14,600 at location in Colorado.
TWM-5000 Total Gross cost ($40k + $5k installation) $(45,000.00)
Value of power produced @16 cent per KWhr Shown $2,336.00
Colorado Rebate $10,000.00
Federal tax incentives $5,219.000
Average annual MACRS depreciation value first 5 years $3,066.67
Net Cost post rebates and first year depreciation $(24,378.333)
every year the MACRS and power not purchased kicks in for about $6,000 per year so the pay can be calculated to be 4 to 5 years.
if you have any questions please go to our web site and send me an email
thank you
Mark Sheikhrezai
I think you need to actually check Your math! 1. The wind is very site-specific, and never blows 20 hours a day, 365 days a year - anywhere (on this planet).2 The power in the wind is directly tied to the Wiebul or Rayleigh distribution profile at a specific site, the elevation, and density are equally important, but you have not factored this in
3. No wind turbine produces full power all the time, only a portion of it, depending on the wind profile, not the wind speed.4 14,600 kWh/year from a rooftop VAWT rated at 5 kW is not going to happen. 5. Federal tax incentives are capped @ $4,000.oo for small wind, not the figure you show.6. You can't depreciate a small turbine at all unless it's an approved turbine in commercial service.7. Your actual payback will be more like 15 to 20 years, not 4-5.
It's interesting but try and measure wind before and after it has to go through that screen. Then measure wind before and after it has been forced to turn down a vent. Then measure wind that has another redirect before exiting. Without measure I can tell you it wastes so much kinetic energy right there that it is inefficient in processing most power with least wind, the goal.
The rooftop unit WindEnergy7.com has is a DIY homeowner kit, has everything with it as a matched kit of components. It's really a handyman level install, many folks put it in themselves and many have an electrician finish it up for safety. Pay by personal or company check, credit card is OK too, takes me about 1 week from cleared payment to ship, UPS Ground.
The DIY <a href="http://windenergy7.com/turbines/?p=44">Home Wind Turbine wind/solar hybrid kit</a> comes with the whole Wind Turbine, Blades, Cone, Tail, Roofmount Kit, Charge Controller, Two Solar Panels, Hardware, and Inverter. The whole Kit of matched components. Did you see the blog post about the 30% federal tax break law, as soon as word got out on that new tax incentive just passed, more interest and buyers came on board immediately.
Our turbines are using stste of the art best PROVEN technology employed in large productive utility scale turbines, scaled down to a homeowner DIY kit. We also make a kit that goes on a flat roof that should do much more with much less. I can't see something with this inefficient design competing with our products. Neat idea though.
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by windmatt
December 10, 2008 6:37 PM PST
- As much as it pains me to be a nabob of negativity - There are a few things that people reading the information about this machine need to consider. I also need to add that I have been in the wind energy business about 30 years, and have had plenty of direct experience with horizontal-axis wind turbines (HAWT's) and vertical-axis wind turbines (VAWT's), which this device is.
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(9 Comments)I will say point blank that this particular machine will not produce the power or the energy that it claims to be capable of providing; it simply cannot - without breaking plenty of laws of physics. First, roof-top turbines are a really bad idea to begin with. They produce vibration (the ones that work do), their place of business is in a highly turbulent and low energy zone that is not conducive to extracting energy from wind because of wind shear,and they require very heavily built roofs that can withstand the extra wind loading that is created by placing a large structure where it shouldn't be placed.
There is a huge amount of data existing concerning the problems with rooftop turbines, and a google search will find much of it. The only roof installations I'm aware of that actually do anything useful are done with good professional grade HAWT's mounted well above the roofline into productive windflow. These installations are very expensive because of the reinforcing work, crane time and copious engineering required to pass building department regulations, and are not recommended for all but the most particular situations. The rule of thumb for an effective wind turbine installation is that the hub height be at least 10 meters higher than the highest objects within 150 meters,
VAWTs, be they out in the open or enclosed inside a mesh-covered shroud, are nowhere near as efficient or cost-effective as a proper HAWT, regardless of their place of installation. This applies to Darrieus, Savonius and all modifications and variants of both types, no matter what the claims of the manufacturer might be. This is the reason why you don't see vast windfarms made up of VAWTs - and why they are all HAWTs -everywhere. The primary reason why this is the case has to do with the actual "effective" swept area of a wind rotor. Because a typical HAWT presents the full rotor swept area as a disc that faces the wind all the time, the generator can extract energy from the entire swept area. With a VAWT, the most swept area that is effective (without being up-winded or shadowed by it's own rotor) at converting wind energy to usable power is approximately 1/3d of the full frontal area. This means that, in order for a VAWT to match the output of a good HAWT at the same windspeed, it will need to be about 3 X as large a structure. This means that the cost of energy is much greater because of the cost of the structure required. Instead of being much bigger, the device in this article is actually much, much too small to produce the claimed output.
There are actual rules and regulation on the near horizon for small wind turbines that will make it quite interesting for all the makers of anything but conforming wind equipment being offered and/or sold in the US. Canada and Europe. All turbines will be rated @ 11 Meters per Second wind speed (24 MPH roughly), and will be required to meet stringent mechanical, electrical and performance criteria prior to being given permission to sell anything. Yipee! The main thing is that small turbines be tested to the standards set forth in the IEC61400-2 requirements. This is the foundation for the up and coming US requirements, and means that testing be done and certified by an independent agency - not self-certified.
Caveat emptor!