EEVblog #1271 - 100kW WindWall Generator BUSTED

[Kleinstein]

This is odd - power going up about linear with wind speed in the low speed range.  This kind of indicates they have a problem with there math. The accepted theory has the power going up like the wind speed to the cube, so much faster.

The energy in the wind is going up with power cubed.
P=0.5*rho*V³*A*C_p  where C_p is Power Coefficient.
The theoretical max. C_p is 0.59 Betz law.
The C_pvalue of an actual turbine varies with pitch angle, windspeed, and rotational speed.
Windturbine manufactures optimize the turbine to have optimal C_p at the windspeed where it is designed to have the most operational hours. Usually 0.45 at 7-8 m/s.
Since the C_p often is like a negative second order polynomial (with a top point of 0.45 at 7-8 m/s.) the power curve becomes almost linear between cut-in and rated.

I agree with most of this, except for the last sentence: With C_p going down below optimum the curve would be even steeper than V³.  Only above the optimum C_p the curve would be slightly less than V³, but normally not much up to the peak power.


Stilt the question why are they trying to fool people: Is it to sell a dodgy product, scam potential investors, get research funds or just as click-bait on you-tube ?

[floobydust]

Fantasy products and technology are very common. Everybody gets to go on a wild ride, fueled with investor's money.
It doesn't matter that it truly doesn't work. Laypeople don't understand energy, the Laws of Thermodynamics, physics, math- any of the basics of engineering and reality.

Theranos scooped up $9 billion over a blood test machine that was not feasible and did not work.
Fyre Festival sold crowds on a music festival that was an incredible scam. The two documentaries about it are worth the watch, to understand the psychology of a scammer.

WindWall was in Saudi Arabia looking for investors- a country that could give zero shits about renewables. Aramco's IPO is valued at $2 trillion now, on oil. So I would say WindWall is a scam, whether to recover the misspent retirement dollars of the dumb exec or just rip off naive investors.

[Bud]

Not to rip off, not to scam, but to milk them. Calmly and steady, for as long as it goes 

[StillTrying]

Their videos of this fantastic invention get about 20 views in 2 years, the EEVblog vid gets 81,000 views in 3 days.

[StillTrying]

Still the question why are they trying to fool people: Is it to sell a dodgy product, scam potential investors, get research funds or just as click-bait on you-tube ?

After reading plenty of their stuff, I think the main problem is that they have no clue, about energy, power, air, wind, simulation, wind tunnels, you name it.

[Fungus]

Still the question why are they trying to fool people: Is it to sell a dodgy product, scam potential investors, get research funds or just as click-bait on you-tube ?

After reading plenty of their stuff, I think the main problem is that they have no clue, about energy, power, air, wind, simulation, wind tunnels, you name it.

Sure they do, they're just pretending they don't because they get more investors that way.

[13hm13]

Dave:
I love your channel and the BUSTED vids.
I also like your 80/90s movie references.
But you seem to neglect the one most relevant: RoboCop (1987).
So with respect to all the ostensibly-sham "Kickstarter" projects, I'll throw a quote out from RoboCop:


=====
Dick Jones : I had a guaranteed military sale with ED 209 - renovation program, spare parts for twenty-five years... Who cares if it worked or not?
Bob Morton : The old man thought it was pretty important... Dick.
=====
Maybe the folks starting these campaigns ... maybe even SpaceX founders ... saw that movie

[Doom-the-Squirrel]

That seems to sum up these situations quite nicely.

[SparkyFX]

If i'd really be up to something, i would get the prototype up and running as fast as possible just to see how it works and have numbers falling out of it as a side effect (and if there only were a couple of immersion heaters running as a load or to test certain variants). If the prototyping is done by yourself the costs are often neglegible, the raw materials shown are not a showstopper.

If this was really beating the competition it would be a snap to have a whole system hooked up to the grid and actually produce an income, but there are only claims and delays. It obviously can't, because the principle is misrepresented.

[floobydust]

What comes first - a working prototype or marketing?  American Wind is taking pre-orders with only a 3D printed mockup 

It's a ducted fan -  which has been studied and optimized for decades - a revolutionary fin technology does not exist.
Rolls Royce, Pratt & Whitney, General Electric, CFM International, Honeywell, Williams etc., even Dyson work on those blades every day. A fan can move air or be moved by air, bi-directional.
The generator looks interesting, if they ever build one. But the system is power limited by the fan and wind forces.

[StillTrying]

Here's one of their early tests, it looks like about 75W @ 75mph.

[floobydust]

Four 50W peanut halogen lamps dimly lit, turbine on the roof of a truck at 75MPH.... is um... terrible power output for that "prototype".
I look at it as impedance matching between the airflow and the fan+generator. That can be improved but even with 100% power transfer, there's not enough power in the first place.

[GeorgeOfTheJungle]

The bulb is 50 Watts, but could as well have been 100 or 200 Watts 

[StillTrying]

The video's only 3 seconds because it disintegrated and blew away at 75.5 mph, probably.

[vad]

Generating ~50W in hurricane force winds (75 mph) - now that sounds believable.

[EEVblog]

Here's one of their early tests, it looks like about 75W @ 75mph.

Well, I'm sold!
 

[Syntax Error]

Dave,

in a business sense, when it comes to investing in distruptive concepts, a Venturi Effect comes into play; when information is forced to flow through a restricted conduit, investors suffer an immediate reduction in their due diligence.

The restricted conduit (bowel?) is often some incredible infographic that promises investors the ability to make the Earth spin backwards, but without any reference to the laws of physics. Despite any demonstrable and sustainable commercial viability, investors still form an orderly queue behind the crowd funding cordon, and get a free key ring, baseball hat, coffee mug or limited edition 'FOMO' tee-shirt.

In 2020, keep on busting these charlatans in the white heat of science and engineering.

[StillTrying]

I didn't know there was a vid of the car in action.

The inventor, Robert, used his knowledge and experience in aircraft technologies and building turbine engines from previous projects with GE Aircraft Engines, Pratt and Whitney Aircraft Engines, and McDonnell Douglas (now Boeing) to help him design and build the MicroCube.

[floobydust]

The Venturi effect does not work because the air prefers to go around the fan. A wind tunnel test would be hilarious.
How much of a fail is that prototype? Power is proportional to V³...
My math, for the area of one module (9.6"x12") it's 45W (27W Betz) with 22.4MPH.  So... at 70MPH... one module theoretical goes up to 1,371W (813W Betz).
The test achieved 1/30 theoretical? FAIL

[Kilrah]

The Venturi effect does not work because the air prefers to go around the fan. A wind tunnel test would be hilarious.

They would duct the entire wind tunnel flow into the fan so nothing can go around... then go on to sell you an InfiniteWall™ that's so big the air can't go around it 

[Syntax Error]

Anyone care to calculate the extra drag those turbines impart on the roof of the car? And how much extra fuel is required to overcome that extra drag?

Thinks: If the under side of the vehicle at speed acts as a venturi tube to create down force, could the turbines produce even more power if slung underneath?  Ignoring the impact 'coefficient' from grit, stones and roadkill.

[StillTrying]

Maybe you could estimate the drag from the output of the turdbeans, if the turdbeans are producing 1 kW of electrical power they're probably producing 3 kW worth of drag.

[BrianHG]

  Car test is useless.  The motion and shape of the body of the car accelerates and raises the pressure of the air significantly going around and over the vehicle frame.  I would say he is getting a 6x-10x artificial boost by mounting the turbines on the roof of the car compared to the 70mph speedometer reading.  Added to the BS of rating the generators in KW/Year instead of kwh, you can see why this guy self deluding dreaming.  Whatever $ he gets, he should pocket and save while he can.  It won last forever.

[Lord of nothing]

@EEVblog
Use the Metrical System only! I have no clue what are you talking about!   

[floobydust]

WindWall scam is in American units- it's still a turd in inches, miles or cm, kilometers.

Are they really getting this far generating 3.3% (1/30) of theoretical?