Speaking of Savomius, and vertical-axis turbines in general, perhaps the most common “talking point” is they are “ideal for urban environments” because they “respond better to the turbulent airflow around buildings” since they “have no need to aim, because they respond to wind from any direction”.
How many times have you heard that one?
Pretty much every time someone is trying to convince you about the advantages of their “new” vertical-axis turbine, right?
I mean, they’ve been saying that same thing for what, maybe 50 years now, right? And when you hear it, your mind sort of half-imagines that SOMEWHERE, in SOME “urban” area, there must be MANY of these vertical-axis turbines, all outperforming whatever horizontal-axis turbines would otherwise have been installed, right? Because you wouldn’t expect to read and hear HUNDREDS of that same statement, even from PhD “researchers”, if it wasn’t well-known and proven that such vertical-axis turbines in fact did perform well in such urban environments, and so there must BE many such turbines actually IN such urban environments, right? I mean, otherwise, wouldn’t that make each and every vertical-axis promoter making that same claim just a plain old LIAR? And wouldn’t that make everyone who believed it and repeated it just A SUCKER? Maybe even an “idiot”?..
So when does anyone ask a follow-up question:
Can you give us an example of such a turbine in an urban environment?
The answer to even THAT is probably a “no” - I can’t think of one - can you? (Other than that little Savonius turbine that Pierre said is mounted on a wall somewhere near where he lives, which reportedly makes very little energy…)
Let alone the REAL question, which would be whether you could see not only the turbine itself, surrounded by buildings, but also see the output data - maybe a power curve, if such a thing is possible in such an environment!
“So Doug, you’re saying that 50 years of this same statement, over and over again, is complete nonsense, and that there are in fact ZERO vertical-axis turbine even mounted and running in urban environments, let alone any making significant power?” *** I’m saying I don’t know of one - do you?
Now on the one hand, you might say “So what? What does that have to do with anything?”
But on the other hand, please realize, this is an example of what the common person assumes he KNOWS about wind energy, and there is absolutely nothing to it! This is the MAIN TALKING POINT for many vertical-axis turbines, and when even slightly scrutinized, it falls apart as complete nonsense!
Yet how many vertical-axis turbine designs have received, and continue to receive, funding based on this repetitive statement, that would appear to have no actual examples? People accept the talking point, and never ask “Where is an example?”…
What brought this to mind is I’ve been noticing the last few days, how our 10-kW turbine on a 120-foot tower seems to be almost always spinning, even when it feels like there is almost no wind down here on the ground. It’s up there, always ready to capture energy from ANY little bit of productive wind, not only up there, but already spinning, so even a momentary gust, lasting just a few seconds, is enough to provide some electricity. That is very high availability. No launchings, no landings, nobody even has to be here, it just does what it does, whenever it needs to do it!
When the topic of wind or solar energy comes up, one problem often mentioned is “intermittency”.
And common AWE talking points are:
- There is more wind the higher you go, so it can make power more of the time;
- It can perform even in light winds due to crosswind travel, which increases even light winds to productive speed hitting the AWE system, giving more availability, and less intermittency.
So then they cite a supposed unusually high capacity factor.
But what about the actual availability of the AWE system to capture all that energy? What if the energy is there, but no AWE system is ready to produce electricity from it at all times?
One question about AWE is not so much whether the concept of higher winds at higher heights is valid, but what good is it, if nobody can come up with a system that can harness all that wind, all day, every day?
So, like most "alternative’ wind energy devices, AWE systems have their own repetitive talking points. but the question in AWE is not so much the existence and high availability of the wind resource, so much as the intermittency and non-availability of the actual AWE SYSTEMS.
Now, is this all part of a well-worn “syndrome”?
Yes it is. Right now, I’m thinking of an old scam that was called “WindTree”, literally promoting spinning rooftop ventilator fans (the ones that look like a beehive?) as the next wind turbine breakthrough, and they were selling, not the turbines themselves, but "territories: which you could BUY, giving you the right to sell the rooftop ventilators (in the near future) in that area.
Like so many scam turbines out there, WindTree promotions would start out explaining the HUGE ENERGY RESOURCE IN THE WIND, as though that was ever in question. They’d cite statistics about how all the wind in the world could power all of civilization 1000 times over, or something to that effect.
It was actually a diversion though, that allowed them to state true scientific facts (about the wind resource), neatly dodging any requirement to address exactly WHY their rooftop spinning beehive ventilators were a better choice than real wind turbines. And it worked. People didn’t notice that, and bought territories instead. As though they were playing “a shell game”. In other words, it was a con! I think I remember people were eventually actually prosecuted at some point, for fraud, or ripping people off, or something…
Anyway, so what does that have to do with AWE? Well, the similarity is, AWE also sells itself by talking about the vastness of the wind resource at heights above where today’s wind turbines operate. This neatly dodges the question of how often the AWE system is AVAILABLE to CAPTURE that energy. from what we’ve seen, the answer is “almost never”.
So this is the kind of thing I’m talking about when I say, we in wind energy have heard all this kind of stuff before, and unknown to the people saying it, it’s very repetitive, and the moment you hear it, if you’ve been in the field for awhile, red flags automatically pop up! Dinggggg! 
