Hello Pierre:
I’m going to summarize your last couple of posts here:
- ’Bbbbut I read on their website, they said they tested it in high winds in the Gobi Desert!!!”
Answer: Yeah, sure, and Altaeros “Is powering” a remote village in Alaska. Oh wait – that was never true! And idle claims on a promotional website do not necessarily overcome the simple facts of LTA aircraft: They are expensive and the materials wear out from being beaten and distorted by the wind and sun. Blimps made heavy and strong enough to truly withstand high winds for long periods are way more expensive and built with heavier construction, and so have less carrying capacity. And let’s not forget the inherent cost and labor and intensive, detailed, ongoing attention required to maintain a blimp and keep it full of buoyant gas!
The economics and engineering requirements of blimps do not change just because some hopeful developer makes claims to that effect on a website! Let’s see some output graphs from actual operation, showing how much power it produced, for how long, and at what wind speed! Idle, general claims mean nothing, and are probably outright lies! Especially when they come from wind energy wannabes, and especially from certain parts of the world where truth is a very loose and elusive concept.
- “And what about brushless Motors? I found some other stuff on the internet about a company that makes small axial-flux motors that weigh less!!! Can’t they just use these lightweight axial flux motors???”
Answer: Yeah, yeah, yeah - every generator I’ve ever made or used has always been brushless - that is what everyone has always used for small turbines, and increasingly for larger turbines. It’s already standard. Has been forever. Professor Crackpot almost always uses axial-flux generators. Why? because they are “different” and there is always that urge to ruin any good invention by incorporating unnecessary features that sound or look cool or different - like using axial-flux generators, or more blades than 3!
The website you linked to mentions cooling systems for their “low RPM” motors that operate at 4500 RPM. That’s about 20 times as fast as the wind turbines rotors will spin. The only way you could ever possibly squeeze that much power out of a small motor is to run it at a far higher speed than a wind turbine rotor will spin, and manufacture a heavy, complicated, gearbox and a heavy, complicated liquid cooling system. So for each motor you’d need a gearbox. And a liquid cooling system, just as Tesla auto motors have. This all gets heavy and complicated, with more failure points.
The fact that you can find a “press-release breakthrough” website making idle, generalized claims of success, with no specific numbers or data to back it up, no scatter plot, no verified power curve, does not change the basic laws of physics that guide turbine design! The VERY FIRST and pretty much ONLY thing a wind veteran will say to any wannabe developer making unbelievable claims is “SHOW US YOUR POWER CURVE”. And you may notice that the website for those motors mentions over and over the ability to “customize” their products. This suggests they have few, if any, actual customers, and are desperate for business of any kind.
Every small turbine uses the equivalent of brushless motors these days. There is little difference between a PMG and a brushless motor, and the most common configuration for home-built turbines, not to mention vertical-axis turbines, has always been axial flux motors, mostly because they seem “different” and are easy to understand. If anything, they are heavier and use more material, including 2 separate steel rotors supporting twice as many magnets total, for the same output as a regular radial flux motor. What axial flux motors do NOT do is drastically change the basic amount of iron and copper required for a given sustained power level.
All this amateurish musing and hypothecating is de rigeur in small wind wannabe circles, and has been beaten to death. All the turbine manufacturers are aware of such options. Still, they build standard PM generators, heavy enough to actually withstand high winds for many hours or days on end, and even then the turbines routinely self-destruct and could not possibly pay for themselves without artificial subsidies or incentives. Not to say there is no way to lower motor weight somewhat with a few clever tricks, but the basic laws of physics, economics, and material longevity do not magically change because someone puts misleading partial information on a website! 