More debunking in small-wind.

I saw the following article in Popular Science, advising against rooftop wind energy.

While I’m not convinced rooftop wind can;t work in some way, this article spells out a few of the headwinds the concept faces.
The article does mention a startup called “Accelerate Wind”

Which looks like another “me-too” “turbines on the edge of a roof” concept.

Some girl with a last name of Boeing seems to be running the show, and so far it seems to be just a show, with not even a prototype, yet they have a million dollar grant from DOE.

You may note a lot of similarities to several bankrupt AWE efforts:

  1. Definitely a group-selfie endeavor - nice group selfie, folks…

  2. They want to place vertical-axis turbines horizontally at the edge of flat commercial roofs, but have no such turbine to place there so they stand there on the roof with a little Air-X turbine (I have one in the garage) and dream. So that is "Professor Crackpot Symptom #2 - choosing the good professor’s cross-axis turbine over a regular propeller-style turbine even though they use a propeller turbine to dream on the rooftop.

  3. They are using a lot of material to create a partial funnel (curved surface)
    hanging off the edge of the roof. This is apparently their “secret sauce” but so far nobody has been able to successfully use such a funnel to create a compelling product since, as a start, the funnel takes more material than the turbine itself. Concentrating funnels are a known symptom of the Professor Crackpot Syndrome #3.


  4. The logo has those little swirly graphics indicating swirling wind - a hallmark of a wannabe wind company going nowhere just like the wind in its logo (sorry to have to point that one out, but it is a big telltale symptom).

All in all, I think the last name of Boeing is what is powering this effort for now.

Uh-oh I just noticed they are in with RIT where I used to play as a kid!

That means I should like them!
BTW I may have mentioned we have greatly accelerated wind near a building here, but it is at ground level, which is good until someone walks into the rotor!

And by the way, they have a roof-edge concentrator (partial funnel) at Argonne National Labs First Turbine Installed at Argonne National Lab — Accelerate Wind
This goes to illustrate that when it comes to wind energy, it doesn’t matter HOW SMART someone may be, the wind will make a fool of them. Imagine, all those “geniuses” at Argonne… :slight_smile:

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Hi Doug, a (0.5 m² ?) Savonius wind turbine has been installed on a gable wall. It looks to work for years. For modest additional production…

We had a small Danish startup that called Edgeflow - crunchbase. They also used to do “edgeflow”. I have spoken with the founder. I believe they ran out of funding before they could sell / deliver a working turbine.

Can’t find any pictures now

Yes I just did a search and like you, did not find much info about that startup.
No pictures to get an idea what it looked like.
On the positive side, Danish.
On the negative side, any turbine using the word “flow” or “flo” in the name, forget it.
Looks like they raised over $300,000 (?)
Man that can build (or buy) a LOT of turbines! What did they do with the money?

https://web.archive.org/web/20140220021222/http://www.edgeflow.dk/

No pictures

Yup good idea, but it provides minimal clarification. After 20 minutes of clicking I saw a reference to enhanced flow at the edges of rectangular commercial buildings. And a bunch of discussions in Danish about attending parties. I could use Google translate, but why go down that rabbit hole. Really didn’t see anything remotely resembling a normal website for a company. Oh well, one more failed wind energy breakthrough - add it to the thousands… :slight_smile:

Hi Pierre
Yes I would say VERY modest. I doubt if it could charge a phone unless maybe there was a hurricane. Probably seldom reaches sufficient voltage to charge anything. If it is grid connected, the smallest inverter probably uses more power at idle than the turbine can even produce. Just a feel-good virtue-signalling decoration. A small Savonius is a good design for longevity though - it never goes too fast so it is still in place after a storm. One way to get a turbine to survive strong winds is if it barely responds to the wind - stay safe: don’t spin fast!

With reduced LCOE rooftop wind power technology could have a substantial global impact.

With reduced LCOE, anything could have a substantial impact.
Nice to have you back in touch on the internet Dan.
Do you have any experience with rooftop wind energy?
I have seen you locate your micro-turbines in many places.
Anyway, there have been a lot of attempts at rooftop wind.
In my case we had a 1 kW turbine running on a commercial building where a friend of mine had a business. The building owner made me remove it. It was a steel and concrete building, but the turbine was still very audible inside. Typically a turbine you don’t even notice any noise from gets very loud when attached to a building. The building is like a hollow acoustic guitar body, and the turbine acts like the strings - lots of music!
Anyway I think it was Aerovironment (who contacted me many years ago as beginners, wanting to know about wind turbines) who finally developed a rooftop design and with great fanfare installed them on the roof of Logan Airport in Boston. Many articles were published on it. The installation has been removed. Not sure why, but they must have sucked. Of course there were no articles on that. The public gets to read the lying fluff, and never end up hearing the truth. Typically when someone buys a small turbine, their first instinct is to mount it on the roof (I got a plan, see?). After all, if the house is 20 feet tall, a tower would be redundant - just use the house. Typically it lasts until the wife hears how loud it is and the project gets “wifed”. That’s what they call it. (It happens so often it even has a name.) Like any self-respecting wind inventor, I’ve got a lot of ideas for rooftop wind energy, but it’s good to be aware of the dismal track record. Just try to find an example of a working rooftop system. Anywhere. (Well except that one in France that Pierre just published on here - that doesn’t count cuz as a Savonius, especially that small, it makes no power.) And it’s not because nobody has tried it - many have, and the less they know about wind energy, the more convinced they are that it is a great idea! Several companies dedicated to the rooftop concept have been added to the dust-heap of ex-wannabe-wind energy companies. :slight_smile:

Maybe instead of roof mounting use a tower up alongside the building to cut out vibrations.

Not sure even that would work 100%
we met folk in Shetland with one outside their house.
A ~10kW scale Literally in their garden. Maximum 10m from the house.
You can hear it when you’re driving by.
I have no idea how the original owner got permission. Must have been one of the very first here

Hi Rod:
Here’s a video with sound, of the 10 kW system at my place, before I replaced it:

Is this the same brand as the one you saw?
They used soft plastic leading-edge tape from the aviation industry, on the outer section of the blades, to avoid blade erosion from high-speed dust. When a corner peels away, it sounds like a large helicopter or a freight train. And the tape only last so long, after which the blades start looking like they have termites making nests in the fiberglass leading edges. When this turbine in the video finally failed I rebuilt another one, replacing the tape with a two-step epoxy-based blade (1) repair & (2) protection system used on commercial wind turbines. Much much quieter now, and it’s paying the electric bill. Hopefully good for a few more years of continuous operation. :slight_smile:

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More debunking, period.
Just saw this article:

Notice how the article starts out with a lie:
A new hybrid flying luxury yacht can land on dry ground
But it comes with an extra-long keel.
That first lie is that this thing even exists - nope, it’s just a bunch of bullshizzle.
Here are more lies:
“The airship will be powered by an air and helium propulsion system, this will reduce the energy needed for air navigation drastically while providing a speed of 50 knots (57 mph/91kph), while the yacht runs on another sustainable power source, an electric engine.”

No details, you are just supposed to “believe” the raw numbers presented, with zero explanation.

Next lie:
" what surprised us the most was the AirYacht’s price positioning will be around the price of a 260/295 feet (80/90meters) superyacht."
OK so this is supposed to be cheaper than a regular yacht. Why would anyone believe that?
Next 2 lies:
“The fuel consumption of our first units will be 10 to 50 times lower than an equivalent 60m superyacht. And the usage of raw materials to build the AirYacht is five times lower than the equivalent 60m superyacht. This is clearly a transition,” he added.

Ok so it will use almost no fuel, and it requires only 1/5 the materials of a regular yacht???

WTF are they even talking about?

Next lie - What powers it?
“Hoddé also revealed that AirYacht is planning to implement a new kind of cruise; aircruise. He says that their technology is not made for traveling from destination A to B but for leisure, yachting, sightseeing, and cruising.”

Aircruise - tried to look it up - just returned the same article, but let’s take a wild guess:
“Aircruise” will involve using pumps to change the buoyancy, and by aiming the blimp to an up or down slant, forward travel can result from ascending or descending. This concept was “floated” as an AWE concept years ago, until someone (me?) pointed out that the energy used to compress the helium to change the buoyancy would be what actually poweres the airship - no free lunch there.

Anyway, OK so is this guess correct? How could they make such outlandish claims that seem to violate the basic laws of common sense engineering? Well because they just imagine whatever characteristics they wish for, and because their craft doesn’t exist, they can pretend it has whatever operational parameters they fantasize.

Just like Professor Crackpot’s wind energy concepts, they “will” have whatever fantasy characteristics make it sound good, because air is invisible, and so it does whatever they say it does. Except it doesn’t exist.
So maybe it uses what was once “floated” as a new AWE idea for powering airships, but the more “down-to-Earth” takeaway is to learn how a story full of lies can nonetheless generate excitement, just to keep us on our toes - ya know… :slight_smile:

You’ve got to be keen to get one this close up

Hi Rod:
Looks like a “Proven” (brand) out of Scotland.
I think they went bankrupt, and are supposedly resurrected by a new group.
We’ve touched on that brand recently, when I had trouble remembering their name.
Now I don’t remember the name of the new company, but they probably won’t last long.
I’d say it looks small for a 10 kW unit. Maybe 3 kW? 1.5?
OK Wait I just google-ized it:

Looks like it’s a 2.5 kW unit
The link erroneously states it is a 1 m diameter - that is obviously wrong. Lots of missing data - I think that 1m figure was just a placeholder til the website author found out the real diameter, then they forgot about it.
Yes that’s pretty low and close to the residence, but if it’s in a good wind it could still work well. At least it’s on a hill. Not sure about the noise. We had one in this area, maybe about that size, which I had a chance to see up close. I don’t remember it being particularly loud, but it didn’t stand the test of time. Had at least one major problem that required something to be shipped from Scotland to California, and only lasted two or three years from what I recall. Pretty much any turbine that close will make significant (noticable indoors) noise in a strong wind.

Could be an SD6
They are common around here

Hi Roddy: When I look at the photo you provided, I’ll take the height of the windows of the house as being about 4 feet tall (1.2 m?), so, considering the turbine is closer to the camera, meaning it would appear larger in scale than the windows, I would estimate that the diameter is around 10 or 11 feet, or 12 feet max, which would optimistically place it in the 2.5 kW range. Just my take from a single photo. A 10 kW unit would normally have a diameter well over 20 feet. 6 kW would be probably 15 or 16 feet diameter. You could possibly check the diameters of their various models and check the unit again and figure out which one it is, or ask the owners, if they even know.

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