The arrangement can even make use of erratic airflow. "The turbulence is a potential benefit, as it draws in kinetic energy from above the [vertical turbine] farm," said Dabiri in an email.
Dabiri said that for large-scale power generation, the hurdles at this point are technical. "We need to demonstrate a cost-effective, reliable vertical axis wind turbine. It's a straightforward engineering challenge, but it hasn't been done yet," he said.
However, on smaller scales, vertical turbines have found a niche among home installers, which mount them on poles or rooftops. Some companies advertise their models as being bird-friendly. Sagrillo is skeptical of this trend. "There's no fuel where you're siting them," he said, pointing out that there often isn't enough wind to make these installations cost-effective at these scales.
He also said that vertical turbines are no safer for wildlife than propeller turbines. "A spinning rotor is a spinning rotor; it doesn't matter how it's oriented," he said.
Still, there are some applications where vertical axis turbines would be ideal, according to Veers. "When people look at very, very large offshore systems, the advantages of vertical axis become interesting again," he said. The advantage of having a lower generator and consequently a lower center of gravity helps lower installation costs on floating platforms in the ocean, where wind speed is typically higher than on land, observed Veers.
In the end, both vertical and horizontal turbines have their trade-offs, though horizontals are a more mature technology. "It's all a matter of the details and how well you have designed the machine," said Veers. "Either one can be an effective machine. In any size range, either one could be effective if you did it right."
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500
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Add CommentOn a discovery program that I can't remember the name off it showed a type of turbine I thought was really clever. It was a vertical type and looked like those spinning things you get on top of flues but was much larger. It turned with wind from any direction. The radical thing was that the spinning part floated on magnets in a ring on the base so that there was no friction. The magnets also formed part of the generator. I have no idea if this was ever pursued commercially but looked like it had a lot of potential.
Reply | Report Abuse | Link to thisSounds really interesting. As I understand (what little that is) turbulence is the enemy of efficiency.
Reply | Report Abuse | Link to thisI saw that show also. I'm surprised I haven't seen more of it, though it could be due to patents and lack of capital to make it more mainstream. As I remember it was much more efficient than today's 'standards' and even worked as rooftop generators for homes and factories.
Reply | Report Abuse | Link to thisThere are a bunch of manufacturers of vertical axis wind turbines. The model that resembled a flue rotor was being marketed by Platek in Canada, and had great promise. For some reason no longer on the site.
Reply | Report Abuse | Link to thishttp://www.ecobusinesslinks.com/vertical_axis_wind_turbines.htm
Overall, verticals have several benefits that outweigh their inconveniences, namely they're much quieter than horizontals, the heavy bits are on the base, and they can be run in much higher wind speeds.
Because the technology is somewhat immature, there is a lack of hard data. But data that has been coming in after wind tunnel testing has shown that the VAWT models have exceeded predicted outputs by up to 40%. Cleanfield's model is a notable one for this.
In an urban/suburban setting, where turbulence and noise would be the enemy of traditional units, small wind VAWT units are ideal for meeting local loads.
PTripp said
Reply | Report Abuse | Link to this" As I remember it was much more efficient than today's 'standards' and even worked as rooftop generators for homes and factories."
That's the one. It was indeed shown on a buildings roof.
VAWT's are the tools of scammers and others who don't really have a clue about physics, economics or how to make cost effective power from the wind.
Reply | Report Abuse | Link to thisWhy is because of their slow speeds, they can't get enough energy from the wind. Since energy is rpmx's torque, you always need 5-10x's size, weight of machine in a VAWT to produce what a good 3blade HAWT does.
How do I know? Because I've built both sereral times and you won't catch me building an overpriced, low output, overweight VAWT when for 10-20% of the cost, I can get it from a HAWT.
It really makes me mad seeing all the scammers ruin wind's reputation with their what can only be called lies about how much their units put out. I watched them in the 70's destroy solar and wind with their scams, delaying our energy independence from big oil, coal.
A great 2kw in 20mph windgen designed well need only cost $500 in parts and labor so why are they selling for $5-10K+? Because of this, Late this I'm building a new improved version of my old design which should sell for about $2k.
RE is fairly simple cheap machines that are not rocket science. Less complicated than a moped. A HAWT is just 3blades, an alternator, some bearings, brushes mounted on a 40-100' pole.
A heat engine is no more than an A/C run in reverse which could use solar, boimass or waste heat to run. They too should cost no more than $2k/kw including the solar collector and/or bioburner.
PV panels are now under $1.50/wt retail if you shop well. Mount them yourself and hire an electrician to wire them up to the inverter/grid for under $2.5k/kw.
If you want to do RE, it really pays to research it well. Their is no reason an eff home can't make all their own power for $5-10k for 25-50 yrs of energy.
Reply | Report Abuse | Link to this@Lazarus
Maybe you were thinking of this:
Mazur's Regenedyne wensite
http://www.regenedyne.com/
Four videos of Mazur's prototype in live test.
http://www.maglevwindturbine.com/HD.htm
The handheld device that you see in the test is a Prova AVM-03 Thermo Anemometer (that measures wind velocity (looks like 50 meters per second in one frame) and air temperature in degrees Celsius.
My impression from many months ago was that Mazur was out to get investors, but was not responsive to technical questions or questions of his cost to build estimates.
I have been studying many diferent designs for wind generators and have been considering a possibility of combining a turbine type generator on one side with a verticle generator offset on the opposing or back side of the turbine generator, thus optimizing the wind at any given speed, if you are intrigued by this design idea let me know at your soonest and I would be willing to work with you on a proportionately balanced design. Respectfully, Kirk Francis
Reply | Report Abuse | Link to thiskirkcb1@hotmail.com
wind technolgy is now technology at particular location (s)etc. using the exsisting means of this wind turbin priencible of its form to but rather bringing the wind to wind turbin can be disiredable if [ veiw of landscape in not dramatilly allterd) I come up with this practicallty and some simplitcation and every aspect those envoled directly and indirectly will gain corbon credits from americas green initave act. [taking the soure to the technology] may qualify as substaible energy]... is what i have drafted. only little enginering needed. perrymanbrian@rocketmail.com implentation means needed
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