The chart used to describe the various inefficiencies of wind turbines is old and based on shoddy data using antiquated wind tunnel only data. Used by now discredited (several times) Big Wind Power shill Mike Barnard, still operating on Quora.com as the “Energy Guy”.
The definition of VAWT usable sweep area is also antiquated viewed as a 2D exposed area instead of cylindrical or spherical/egg shaped working area.
Modern VAWTs like UGE or the now defunct Quiet Revolution are small and 20% inefficient compared to HAWTS (Bergey, Sykstream/Xeres et al), where the ROI, or Break Even point is 10 years for these VAWTS typically, even when properly sited in 7 m/s Weibull mean Average wind distribution at a 20m or 66 ft pole height with no obstructions for 200 m (220 yards or 660ft.) from any wind/compass direction, ala Bergey or Skystream/Xeres and their suggested mount heights to achieve their rated performance at 11 m/s, where Bergey et al will break even in 6-7 years, before the owner is required to replace the blades in year 7 or 8 ( the blades wear out and flatten, lowering output by as much as 35% if left installed) which pushes the BE or ROI start back up to 8 years for Bergey et al (this similar straight blade HAWTS, Skystream being the exception) , meaning the LCOE levelized cost of Energy over a 20 year useful period sees the HAWT crowd of Bergey et al come in 20% better than UGE et al… and other similar small VAWTS.
The reality is these small HAWT and VAWT designs are all very old, UGE has copied a water turbine patent from Gorlov as has Quiet Revolution, (they probably owe the old boy some sort of restitution), none of which start well in air (cut in wind speed is typicaly 4 m/s) , both require sophisticated and costly electro magnet braking, both are stupifyingly heavy, requiring massive expensive pole and foundations. Bergey concieved heir design off a Beechcraft propller design in the ate 1970s, perhaps only Skystream has a modern HAWT design which is much quieter than Bergey, although not as quiet as a the new supercomputer designed VAWT tech (see http://www.starwind5.wordpress.com
There is another new class of VAWTS emerging which are five blade from Ropatec (Italy), Harvistor(Starwind5- Canada), SAWT(China) which use the gyromill(Ropetec and SAWT) straight blade inverted airfoil design or the curved blade , and the similar inverted airfoil no tip eggbeater design, and also like UGE fly the airfoil shape lift toward the shaft, something both Quiet Revolution and the grand daddy commercial VAWT player VAWT never figured out. (Vestas ironically had single and bi-blade double rotor VAWTs with outward flying airfoils in the late 1970s, as well Deutsche Aerospace and the Swiss tried double blade systems as well in the 1980s and early 1990s, attempting to recreate earlier CDN MNR/NRC and NASA/Sandia/NREL/Flowind work)
The five blade new tech VAWTS have higher solidity, lower tip speeds and generally can operate at 25-35% lower mount heights and deliver the same performance at these heights as that achieved by Bergey et al, where the tower costs are 25%-50% less, even though the turbines themselves are 10-20% more expensive (they use more material to gain higher solidity). All new tech VAWTs have a larger raw addressable market as they can be placed just above tree and building heights and be generally 50%closer to these objects because of their airfoil shapes and higher solidity can operate in turbulent semi-laminar flows and still achieve better performance as the HAWTs by 35% placed at the same height in the same location. This means new tech VAWTs have more siting opportunities than old tech VAWTs and HAWTs.
So the verdict is still not in on wind turbines, with Sandia only working on 5,10 and 15MW VAWTS for offshore as are the French, the Big Wind turbine game is changing, even Mitsui is revisiting the VAWT in Japan (underwater).
On thing for sure we do know is the price of Offshore HAWTS is nearly double around US $ 4.50/W installed over their inland ground mounted cousins at US $2.25 to 2.50/W installed with offshore VAWTs promising to land somewhere in the middle at US $3.33/W, depending on which article you read. It also means inland mounted VAWTS wil surely fall in price to be somewhere below 2.25/W in the near future for large VAWTs as they hit the market.
One interesting VAWT fact which is often overlooked is the power/hectare or power/acre power density of using densely configured VAWTs, ala Windspire and other VAWTs (Turby et al, ) depolyed in the former at NREL/U of C tests and the in the latter at Uni. of Delft tests, testes which conclusively and independently show power density of VAWTs using counterclockwise and clockwise rotating VAWTs in a dense staggered pattern can produce 400% more power in the same physical foot print with 5X less wake and trailing pressure disturbances, disturbances which are the cause of sinus pressure fluctuations and related headaches for those inhabitants located down wind from today’s big HAWTs.
What we do know at Harvistor, our Starwind5 systems does work as advertised based on field tests of the prototype see gizmag “Darwind5” to view the video (Circa 2012), and soon we will be in production looking to deliver small wind solutions for 65% of the cost they can be installed for now by Bergey et al.
So the world of wind power big and small is indeed changing thanks to super computer driven intelligent design and new breakthroughs in light weight and low cost bio materials with much smaller CO2 footprints.
Follow on… UGE? the great pretender?
We , Starwind5 have been compared to UGE recently so its worth a follow up note for everyone to consider…
UGE is what it is, an old Gorlov design, updated with reverse airfoils that has been marketed heavily. All you have to do is look at the twin UGE Eiffel tower and realize it is an Art only installation, great for marketing (like Windspire in most cases) but UGE is not a serious power generation facility and has no hope of competing in a heavily LCOE “Levelized cost of Energy” scrutinized bid for small wind.
The research is out there on the Sandia site, dont take my word for it, have a look, VAWTS are coming back in Big wind and for good reason… (pole height, less aerial service which is expensive, less foundation, better efficiency in low mount wind, many say they also look better, with less horizon blight for the NIMBY crowd… with much better ROI and LCOE).
You would do yourself a favour by Checking out Paul Gipe’s site as well at www.wind-works.org
to see where UGE/Quiet Revolution fit , Turby as well)
At Harvistor we stay focused on science and field testing with Starwind5, not marketing arm waving. (and yes you will see early deployments very soon of this new VAWT tech in late 2015 and early 2016.)
The proof will be in the installations that are still standing 20 years from now nd what will be placed offshore in the next 5 years in the 5, 10 and 15W class (it wont be dominated by HAWTS this is certain given Lockheed runs Sandia, and they are building the offshore platforms for what Sandia is designing…, Lockheed’s home base is Atlanta, and they are looking to make a major stake the whole USA East Coast for offshore wind power).
It’s still early days, heck the current Big Wind HAWT crop is a 1947 Danish design that relies on weight and centripetal forces more than it does on a sound aerodynamic lift/drag and turbulence management model, and the aero-elastic model work around of tipped up sweep area is really quiet farcical when you think about it.., all in the name of tip control to avoid nasty bearing and planetary gear damage caused by tip vibration as the air pressure changes between pole and tip, invariably causing the blade to flex, and send those nasty vibrations directly back to the nacelle mounted bearing hub and through the main rotational shaft and into the transmission to cause some very nasty problems, which are best fixed with the now power producing and very costly fix of simply shutting down the turbine. No wonder these big boys don’t work on windy days, its because they cant as they risk almost certain gearbox destruction.
This is why Big Wind routinely operates at 24% of nameplate on average when you factor in downtime for high wind, never mind lightning strikes on 3 out of 100 turbines annually in most locations, which also cause shutdown. Woe to the Big Wind farm investor seeking the initial promised return, it almost never happens.
I suggest you contact Sandia for more details, Mitch Barone is sure to elaborate on this properly. (Even though they pulled him off the offshore VAWT project to work on HAWT blade designs…)
The world of wind power is changing my friends, rapdily, and it’s all for the good led by new tech VAWTs.
Director Harvistor LLC