Wind Turbine of the Future?
Wednesday, August 27th, 2008
This inventor’s webpage has a great synopsis of why this technology beats single rotor wind turbines in power output, especially at low wind speeds, so we won’t rehash the arguments here.
I invite our readers to read about this innovative idea at the inventor’s site:
http://www.speakerfactory.net/wind_old.htm
I’ll just pose some questions here in the hope that what remains of my skepticism can be banished:
1) Since the flexible axis bends under the weight of the rotors, rotation of such axis would cause the direction of torque caused by downward pressure on the pivot point to continuously change. Would this accelerate a stress fracture and eventually cause the axis to snap? It will be interesting to observe the longevity of the multi-rotor design, especially as the technology is scaled up to produce greater power output, thus increasing rotor size, and/or number of rotors mounted on a single axis.
2) The long arms of the axis rotate to automatically position the rotors correctly into the wind. This huge circumference of rotation produces a footprint much larger than a single rotor wind turbine would create. With a multi-megawatt single rotor wind turbine, the next turbine can be placed a relatively shorter distance away. To scale the multi-rotor wind turbine to match the megawatt output of the single rotor design would make that circumference even larger. The question is, if in a given plot of land the maximum density of wind turbines of either design were to be installed, which design would achieve the largest power output per square-unit of land utilized? In other words, which design conserves the most land?
Finally, I pose an observation in the form of a question requiring further empirical study: Since the wind flux of this turbine is smaller, that is, the rotors pierce a smaller cross-section of the wind field, would you think that this technology can potentially cause less harm to migrating birds that the current wind turbine with its long blades? In other words, a bird has a better chance of flying around this apparatus? (Not that I am that worried about birds getting caught in the old design, since wind turbines probably cause less destruction of life per unit of power output than a coal-burning power plant does, and yes, I mean people, whose number of deaths caused by respiratory problems is increasing. Of course, there are those in the green movement who value animal life more than human life, but don’t count me among them. A small number of birds is a worthy sacrifice for the good otherwise being achieved. If you don’t agree, go ahead and flame me!)
We would welcome the designers’ thoughts on this subject, as these questions were meant not to criticize what might be a breakthrough design, but to spark more discussion and even offer the designers an opportunity to further present the advantages of their invention.
I hope that this concept, or another one like it, helps the United States take the lead in renewable energy. It seems that we are late to start solving a problem, but we excel when we take it seriously. I hope we can congratulate these people someday soon.
