American Wind - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: December 09, 2019, 02:45:06 am
content: It should likely be in the Dodgy (Marketing) Technology section:I can smell something in the wind, and it'shttp://americanwindinc.com/our-products-3/

author: EEVblog
author_rank: Unknown
timestamp: December 09, 2019, 02:48:28 am
content: 1kW from a 9" cube at 45MPH ?Regular small wind turbines are half that power at 1m diameter.

author: BradC
author_rank: Super Contributor
timestamp: December 09, 2019, 08:33:24 am
content: The blurb mentions something about the us patent office but I've not had any luck finding a patent.

author: EEVblog
author_rank: Unknown
timestamp: December 09, 2019, 10:08:44 am
content: Quote from: BradC on December 09, 2019, 08:33:24 amIf you do let me know, making a video on this now.

author: EEVblog
author_rank: Unknown
timestamp: December 09, 2019, 10:18:45 am
content: Got it:https://patents.google.com/patent/US9331534B2/en

author: MagicSmoker
author_rank: Super Contributor
timestamp: December 09, 2019, 11:13:24 am
content: According to the equation/calculator on the below website you need a rotor swept area of at least 2.35m (ie - greater than 1.5m2) to deliver 3kW at 45mph (20m/s):https://www.ajdesigner.com/phpwindpower/wind_generator_power_rotor_swept_area.phpGiven the dimensions of the unit and the fact that less than 3/4th of the area is used by propellers I'd say theis pegged.

author: ciccio
author_rank: Frequent Contributor
timestamp: December 09, 2019, 11:28:03 am
content: the specs are intriguing : the Microcube delivers:Max Output: 1kWMax Voltage: 180v (DC) (lower case v)Max Amperage: 6a (DC) (lower case a)and maybe this is the reason for having power value (in upper case Watts) different from the product of lower case volts and lower case amps.Trying not to laugh, I simply cannot believe that this can be true. STOPBest regards

author: BradC
author_rank: Super Contributor
timestamp: December 09, 2019, 01:16:42 pm
content: Quote from: EEVblog on December 09, 2019, 10:18:45 amNice, so they've patented the alternator configuration that the guys making home made wind turbines have been using for years.

author: Someone
author_rank: Super Contributor
timestamp: December 09, 2019, 09:43:52 pm
content: If you keep focusing on the optimal wind speed the numbers will never add up, but the nameplate rating is the maximum power which appears plausible at their maximum wind speed. Then it becomes a silly game of maximising the peak output ratingorload factor.

author: SL4P
author_rank: Super Contributor
timestamp: December 10, 2019, 12:11:03 am
content: I’d like to see the internal buss bars used to distribute all this power.

author: Someone
author_rank: Super Contributor
timestamp: December 10, 2019, 06:42:42 am
content: Quote from: SL4P on December 10, 2019, 12:11:03 amSingle digit Amperes are moved around in solar installs on surprisingly thin copper wires, why would this be any different?

author: EEVblog
author_rank: Unknown
timestamp: December 10, 2019, 09:32:04 am
content: Quote from: Someone on December 09, 2019, 09:43:52 pmBut the optimal wind speed is the entire point of wind turbines.But bottom line is the capture area. They claim to break Betz's law, but even if they did to get 100% efficiency, that's only an extra possible 41% power tops.It's bullshit.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 10, 2019, 12:20:07 pm
content: The claim maximum voltage and maximum current, but those may not be available at the same time. So peak power is not max. voltage time max. current.Another point they can fail is testing in a wind tunnel that is to small, so that the wind can not flow around freely. This could fool them into too high a reading, possibly way too high.

author: iMo
author_rank: Super Contributor
timestamp: December 10, 2019, 03:52:12 pm
content: I would mount that on my e-bicycle's handlebar. At 20mph I get maybe 1kW, that is enough to speed up my bicycle to 45mph where I get 3kW, and so on. It could be I break the sound barrier after a while then..

author: bsdphk
author_rank: Regular Contributor
timestamp: December 10, 2019, 08:09:08 pm
content: The "funnel" in front of the propeller is a dead giveaway, it is physically impossible for it to improve efficiency in any way.Also: I'd would not want to live a place where 45mph wind was common enough to make a wind generator with that optimum economical.

author: Someone
author_rank: Super Contributor
timestamp: December 10, 2019, 08:53:36 pm
content: Quote from: EEVblog on December 10, 2019, 09:32:04 amYou're grossly misrepresenting their claims in your post:Quote from: EEVblog on December 09, 2019, 02:48:28 amWhen that is clearly not what they claim, even adding a disclaimer on their website for people who can't understand peak specifications:Quote from: American WindThey claim to have a wider operating range in both directions than other products. So a poor load factor but high availability (they use the term uptime for this).The silliness with outrageous claims appear to be limited to the Advanced Wall "product", claiming peak power from 17mph up, and 18kV operating voltage. Kleinstein has suggested one of the ways such an unreasonable result could be arrived at.

author: Someone
author_rank: Super Contributor
timestamp: December 10, 2019, 08:57:15 pm
content: For posterity:http://americanwindinc.com/our-products-3/advanced-windwall/

author: EEVblog
author_rank: Unknown
timestamp: December 10, 2019, 11:46:09 pm
content: Quote from: Someone on December 10, 2019, 08:53:36 pmAnd that's what my video will focus on. But the Advanced Windwall is just 100 Microcubes stacked, so the claim also must extend to the single cube.

author: ejeffrey
author_rank: Super Contributor
timestamp: December 11, 2019, 12:04:33 am
content: Quote from: Someone on December 10, 2019, 08:53:36 pmThe triple version dave posted the screen shot from clearly states that it 3 kW @ 45 mph. Although perhaps despite the appearance it isn't just three "microcubes" stacked in a triangle. Or maybe the "specs" are just confusing and inconsistent.But if it is 1 kW/cube at 140 mph that is kind of a pointless specification unless you really need power in the eye wall of a category 4 hurricane.

author: EEVblog
author_rank: Unknown
timestamp: December 11, 2019, 05:39:37 am
content: Quote from: ejeffrey on December 11, 2019, 12:04:33 amThat's why I'm going with the big 100kW one that comes with a real looking power output graph and very clearly claims 100kW at 17MPH.A power performance graph is the ultimate reference in this industry.http://americanwindinc.com/our-products-3/advanced-windwall/

author: wilfred
author_rank: Super Contributor
timestamp: December 11, 2019, 06:11:51 am
content: There are some videos on Youtube so anyone interested can hear the story straight from the horses mouth. The first video even shows they have patent 9331534B2. My first impression of the inventor was he seemed sincere and genuine and not prone to marketing speak. But you can listen and make up your own minds. The videos are only a few minutes long.

author: EEVblog
author_rank: Unknown
timestamp: December 11, 2019, 06:41:10 am
content: I ran the calcs on a single 9" cube at the 45MPH figure, you get 280W maximum power in the wind in that square area at 20degCGetting 1kW out of that would require over-unity

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: December 11, 2019, 09:34:52 am
content: Quote from: EEVblog on December 11, 2019, 06:41:10 amAnd I get even less than that: The area is 0.052 m2(1), the air speed is 20.1 m/s (2) => The volume of air through the fan is 1.04m3/s (3) Air density is ~= 1.2 kg/m3=> the kinetic energy of that air is210252 joules (4), which per second = 252W and the thing generates 1kW? Sure!(1) (9*0.0254)^2(2) 45*1609/3600 (72 km/h)(3) 20.1*0.052(4) mv2/2 =1.04*20.12/21.04*1.2*20.12/2Edit:  fixed: forgot to apply air density :-)

author: EEVblog
author_rank: Unknown
timestamp: December 11, 2019, 10:37:36 am
content: Run the same calc on the 100kW version at 17MPH and it's

author: wilfred
author_rank: Super Contributor
timestamp: December 11, 2019, 11:38:32 am
content: Quote from: GeorgeOfTheJungle on December 11, 2019, 09:34:52 amI haven't read how the calculation is done but I would have thought the volume of air would be the air passing through the turbine. Which is circular. What am I missing here?BTW the video is still unlisted.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: December 11, 2019, 11:57:24 am
content: Quote from: EEVblog on December 11, 2019, 10:37:36 am10*10 fans => 5.2 m2, 17 mph = 7.6 m/s => mv2/2= (5.2*7.6*1.2)*(7.6*7.6)/2= 1370 Joules, per second = 1370 WattsQuoteYep, but I'm supposing that the air has no other way to go than through the turbine, it's the very best possible scenario and even so...

author: EEVblog
author_rank: Unknown
timestamp: December 11, 2019, 12:48:32 pm
content: Quote from: wilfred on December 11, 2019, 11:38:32 amThe square sides taper in toward the funnel.What is your point?QuoteYes.

author: bsdphk
author_rank: Regular Contributor
timestamp: December 11, 2019, 03:05:09 pm
content: "The square sides taper in toward the funnel.What is your point?"Contrary to everybodys "intuition" that "cowling" does not lead more air through the propeller.To get more air through the turbine, you would have to increase the pressure in front of it.So you imagine that happening.Then consider the air a little further out for a moment.When was the last time you saw air compress itself ?All you achieve with that cowling is to produce a "pillow" of stalling air in front of the propeller and that reduces the efficiency, instead of improving it.This is very basic physics 101: To extract energy from any laminar flow, your intake must have smaller area than your outlet, because the energy you pull out causes a drop in velocity and/or pressure and total energy is conserved.

author: wilfred
author_rank: Super Contributor
timestamp: December 11, 2019, 04:00:32 pm
content: Quote from: EEVblog on December 11, 2019, 12:48:32 pm@GeorgeOfTheJungle has already informed me that even with ageneroussimplifying assumption of a square frontal area for the turbine the results are not encouraging. A circular area of just the size of the fan blades would let even less air through the device. I wanted to clarify if he thought as you do that the tapering sides funneled a greater volume and hence energy through the turbine. I didn't think it would but I wasn't sure. I thought it might just be for some reduction of turbulence of the air entering the turbine blades, or for giving unsophisticated buyers the false impression it was part of the design aerodynamics for improving performance. Or just for style reasons.My point was also to as diplomatically as possible give @GeorgeOfTheJungle a heads up to a possible error that I wasn't at all sure he had made.Not being a Patreon I overlooked that you give supporters early access.

author: EEVblog
author_rank: Unknown
timestamp: December 12, 2019, 02:42:58 am
content: Quote from: wilfred on December 11, 2019, 04:00:32 pmIt's for styling and likely practical design reasons like hiding wiring and any circuitry. I would have gone with a honeycomb structure myself and let the air also pass around the outsides.What impact it has on the performance I don't know, but it doesn't matter about details like that. Because the entire process of debunking something like this starts by taking the best case zero losses ideal aspect and seeing if it gets near the claims, it doesn't by more than an order of magnitude. Only if it comes close to the claims do you then start investigating the finer details.

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2019, 06:32:37 am
content: I imagine this was tested during a hurricane to get those figures? lol.