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Novel wind turbine designs
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18-04-2013 10:35am#1In this thread, let's have a look at alternative wind turbine designs to the large propeller type.
A small, quiet, vertical wind turbine suitable for urban environments. $5,000 for 1.2KW max. I don't know what the average output would be.
Then have a look at this proposed Dutch wind generator with no moving parts that relies on the movement of ionised particles.
A Kite that generates electricity:
Any others?3
https://www.youtube.com/watch?v=Z2EonAJA4bM
https://www.youtube.com/watch?v=tqksCHWROBU
https://www.youtube.com/watch?v=QlSHH_djn94Comments
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OssianSmyth wrote: »1938 "Electricity from mighty wind towers"
Could you imagine the objections to those bad boys...:pac::pac::D0 -
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Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,746 Mod ✭✭✭✭
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And since the Japanese turbine uses twice as many blades you'd expect it to be able to harvest twice the power per swept area too.The Japanese wind lens increases the effective diameter of the turbine.
To compare like with like, they should compare the power output of a standard 3 blade design having a diameter the same as the outer diameter of the wind lens.
There is a reason the Mil-26 has 8 rotor blades and the Bell only needs 2.
Links to larger image
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Phill Ewinn wrote: »
Micro wind turbines. Bit like solar panels. Lots of them linked together is the trick.
Same concept with a Savonius type.
From Graeme Attey
I'd suspect these are just novelty though.
Can't beat a 3 blade HAWT in moderate clean air for cost versus return.
A lot of these promo videos could benefit from an ammeter readout with the turbine under load.0 -
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Capt'n Midnight wrote: »The benefit of roof tip is that the roof channels air into them so some chanelling of wind.
but of course they are completely useless if the wind changes direction and is blowing from the side of the house
Turbulence would be what I was thinking, although the Savonius types favour it more than most. Low rev. generators are a pain. I'll wait for the field results.Capt'n Midnight wrote: »the show stopper for these might be third party insurance in case there is turbulence and the kite nose dives into someone.
Well the logistics of taking off and landing a Spruce Goose wing with a net return of energy and a robot rugged enough to steer and anchor it I think might be a significant hurdle too. 0 -
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Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,746 Mod ✭✭✭✭ Join Date:Posts: 88986
Sir Liamalot wrote: »Forgot about this one.bitat.com/wp-content/uploads/windfreeways.jpg[/IMG]
Horizontal Helical Darius (concept)
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Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,746 Mod ✭✭✭✭ Join Date:Posts: 88986
it's not idealSir Liamalot wrote: »
Ideal VAWT (minimal reverse buffeting). Blue arrow is wind direction.
some tug boats use something similar, but curved
http://articles.maritimepropulsion.com/author/Backwell.aspx?page=8
but no matter which way you do it, a Vertical axis means you have drag from the rotor advancing into the wind, and it's a v squared thing, or you have to shield part of the rotor which reduces you wind collection area / means you have to use a lot more material to construct it
BTW the aneometer that uses half spheres spins at exactly 1/3rd of the wind speed, for real world numbers on vertial axis
now remember the kinetic energy of wind is half m v squared so the aneometer would only extract one ninth of the energy0 -
Yeah the gearing will introduce 30% mechanical losses. I've seen some riding on magnets instead of bearings to reduce this. Either way VAWTs are pointless ornaments. The thread is "novel designs" though not "which one is these has any practical application where you might rely on it being useful." If it was then propellers would be the ticket. And anything on a roof would be
.Paul Gipe wrote:
"Vertical Axis Wind Turbines
February 7, 2013 Paul Gipe.
FloWind: The World’s Most Successful VAWT (Vertical Axis Wind Turbine)
Note: The following is an excerpt from my, (Paul Gipe), 2009 book Wind Energy Basics Revised: A Guide to Home- and Community-scale Wind Energy Systems. I am reprinting it here because of the constant re-invention of Darrieus or Vertical Axis Wind Turbines (VAWTs) and the presentation of these devices as though nothing like them has gone before. The data presented here is from actual performance records collected by the state of California.
The most successful VAWT in history was that developed by FloWind in the early 1980s. Using what has become a rather conventional two-blade phi-configuration or “eggbeater” Darrieus, FloWind installed more than 500 turbines in California’s Altamont and Tehachapi passes.
By the end of 1985, FloWind, an American manufacturer, had installed 95 MW of its signature product. For comparison, that’s equivalent to more than 15,000 of Quiet Revolution’s sleek 5-meter (16-foot) diameter turbine.Installation of a FloWind 17-meter Darrieus turbine in the Tehachapi Pass in 1984.
At their most productive in 1987, FloWind’s fleet generated 100 million kilowatt-hours—enough electricity for nearly 20,000 California homes. No VAWT manufacturer to this day has ever come close to rivaling that accomplishment. On any windy day in Tehachapi during the late 1980s, the sun could be seen glinting over hundreds of Flowind’s turbines spinning atop Cameron Ridge.
However, generation began collapsing as serial failures in the joints between the sections of extruded aluminum blades overwhelmed the American company. By the late 1990s, FloWind was generating one-tenth the electricity it had in 1987. By the end of 2004 nearly all of FloWind’s Tehachapi turbines had been removed and sold for scrap. Some relics were still standing in the Altamont pass in 2003, though they too were slated for removal.
By the time the last of FloWind's turbines were taken out of service, the fleet of Darrieus turbines had generated a lifetime total of nearly one billion kWh. It is unlikely that any VAWT will ever come close to that record.
The wind industry worldwide learned a lot from the FloWind experience. FloWind proved without a doubt that VAWTs could reliably generate commercial quantities of electricity—at least for a decade. But FloWind’s aggressive marketing and high power ratings have tainted vertical-axis technology ever since. Much of today’s cynicism about new VAWTs derives from FloWind’s hype about its turbines and its manipulation of power ratings.
FloWind’s turbines were large commercial wind turbines of the day. They built two models: a 17-meter and 19-meter version. The 17-meter turbine, for example, was about 17 times the size of the architecturally dramatic Quiet Revolution QR5.
Characteristic of FloWind’s marketing, and that of other Darrieus turbines of the day, including DAF-Indal, and VAWTPower, was the turbines’ high power ratings. FloWind’s 17-meter model was rated at 142 kW at a wind speed of 38 mph (17 m/s), their 19-meter model was rated at 250 kW at a wind speed of 44 mph (~20 m/s). For comparison, that’s a Force 8 or “fresh gale” on the Beaufort scale. Translation: That’s so windy no one in their right mind wants to be outside.
To understand these power ratings, it’s necessary to look at the area swept by the eggbeater-shaped rotor. FloWind’s 17-meter model swept 260 m2, equivalent to a conventional wind turbine 18 meters (60 ft) in diameter. The 19-meter model swept 340 m2, equivalent to a conventional wind turbine 21 meters (70 ft) in diameter. Today, turbines of this size are considered small commercial turbines.FloWind 17-meter Darrieus turbine on Cameron Ridge during the 1990s.pi Pass in 1984.
For comparison, a conventional wind turbine 18 meters in diameter would typically be rated at 100 kW, and a 21-meter turbine would be rated at 150 kW. Thus, the FloWind turbines were overrated in comparison to their peers by at least 50%.
The high ratings of the FloWind machines translate into a specific capacity 546 W/m2 for the 17-meter model and an incredible 735 W/m2 for the 19-meter model.
Another way of saying this is that the 17-meter model had a specific area of 1.8 m2/kW and the 19-meter model a specific area of 1.4 m2/kW. Conventional turbines of the day swept 2.5 m2 for every kW of generator capacity.
That FloWind was greatly overstating the potential performance of its turbine was reflected in its average capacity factor, a measure of performance relative to the size of the turbine’s generator. The capacity factor of FloWind’s turbines never exceeded 12 percent on average and was often less than 10 percent at a time when conventional wind turbines were delivering twice that.
Why were FloWind’s power ratings so high? Wind turbines of that era were often sold to uninformed investors who compared wind turbine prices based on the cost per kilowatt of installed capacity. FloWind’s aggressive power ratings enabled them to charge far more for their turbines than they were worth. FloWind’s turbines were never truly in the 150 kW or 250 kW size class, but that’s what they charged their investors.
Despite these outlandish power ratings, FloWind’s Darrieus designs turned in a respectable performance relative to the area of the wind stream swept by the two-blade rotor. During good years, Flowind’s machines would generate 500 to 600 kWh/m2/year, competitive with conventional wind turbines of the day.
FloWind Darrieus turbines seen on the Cameron Ridge during the annual Windmill-Wildflower hike in the Tehachapi Pass in the 1980s.
The bottom line: FloWind’s Darrieus turbines operated for about a decade generating millions of kilowatt-hours, and in doing so delivered respectable performance until fatigue and design weaknesses led to increasing unreliability and they were removed. FloWind’s turbines, when in regular service, delivered about the same performance as nearby conventional wind turbines relative to their swept area, but performed poorly in comparison to their inflated power ratings.
Because of scale effects, it is unlikely that the small wind turbines of the modern VAWT revival will approach the historical performance of FloWind’s large wind turbines."0 -
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French wind startup to make turbines that look like trees
http://news.discovery.com/tech/alternative-power-sources/tree-shaped-wind-turbines-blend-into-the-scenery-141230.htm0 -
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Counter rotating blades turn the commutator against the "stator".
I'm betting the additional material cost outweighs the production increase.0
https://www.youtube.com/watch?v=vQexzNg_e9A
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