Comments on: Urban wind power inspired by ancient Persia

The shape of urban wind power continues to morph. The latest twist come from Windation, a company with a design inspired by centuries-old "wind catchers."

[NBaldwinUSAF]

This is a GREAT idea! If the company can get the price down, every company in America could have one!

[sanenazok]

Math check?
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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?

[Joe Real]

California and Federal have tax rebate to wind in the same as solar, on a per watt basis.

[sanenazok]

One other thing, the website says a patent is pending, but I can't find patent applications assigned to a "Windation" both with the USPTO and WIPO.

[Sheikhrezai]

Thank you for your comments above
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

[windmatt]

Mark,

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.

[WindEnergy7-com]

I am a designer, developer, and fabricator of small wind energy products that my company sells online. We have a growing dealer network of individuals who use my products. Customers have found the kits to be easy to deploy and understand. Many customers have found it easy to become customer/dealers.

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.

[Sheikhrezai]

Try and get a permit for PROVEN wind turbines in an urban setting!!

[windmatt]

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.

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!