Schools of fish inspire wind farms with 10x as much power output per unit area

[Bill USA]

http://www.treehugger.com/files/2010/05/fish-inspired-wind-farms-are-10x-more-powerful.php">Fish-Inspired Wind Farms Are 10x More Powerful

Marine life has proved itself a rich source of inspiration for renewable energy innovation. Sharks and kelp have sparked ideas for harnessing wave and tidal power, and humpback whales have bumpy fins that turn out to be perfect for improving wind turbine blades. Now,
researchers at the California Institute of Technology (CalTech) have found that observing schooling fish unlocks clues to better vertical axis wind turbines and setting up wind farms, which could yield as much as 10 times more energy from the same amount of space.

Fluid-dynamics expert John Dabiri uses bioinspiration for coming up with better solutions for water and wind energy. According to Dabiri, schools of fish offer a wealth of insight into setting up better wind farms using vertical axis turbines.

"I became inspired by observations of schooling fish, and the suggestion that there is constructive hydrodynamic interference between the wakes of neighboring fish," says Dabiri, associate professor of aeronautics and bioengineering at Caltech. "It turns out that many of the same physical principles can be applied to the interaction of vertical-axis wind turbines."
~~
~~

With optimal placement, Dabiri thinks we could get 10 times more energy out of the same wind farm using vertical instead of horizontal turbines. A test of the fishy findings is underway with a pilot program called The Caltech Field Laboratory for Optimized Wind Energy (FLOWE). Two plots of land in the LA area will be home to six vertical turbines (three of which are provided by Windspire Energy) on mobile platforms, which will be moved around to test different configurations and discover the best patterns for wind farms.
(more)

for those who really like to dig into the technical details here's a link to Dabiri's paper:
http://dabiri.caltech.edu/publications/Da_JRSE11.pdf">Potential order-of-magnitude enhancement of wind farm power density via counterrotating vertical-axis wind turbine arrays

Abstract

Modern wind farms comprised of horizontal-axis wind turbines (HAWTs) require significant
land resources to separate each wind turbine from the adjacent turbine wakes. This aerodynamic
constraint limits the amount of power that can be extracted from a given wind farm footprint.
The resulting inefficiency of HAWT farms is currently compensated by using taller wind
turbines to access greater wind resources at high altitudes, but this solution comes at the expense
of higher engineering costs and greater visual, acoustic, radar and environmental impacts. We
investigated the use of counter-rotating vertical-axis wind turbines (VAWTs) in order to achieve
higher power output per unit land area than existing wind farms consisting of HAWTs. Full-scale
field tests of 10-m tall VAWTs in various counter-rotating configurations were conducted under
natural wind conditions during summer 2010. Whereas modern wind farms consisting of
HAWTs produce 2 to 3 watts of power per square meter of land area, these field tests indicate
that power densities an order of magnitude greater can potentially be achieved by arranging
VAWTs in layouts that enable them to extract energy from adjacent wakes and from above the
wind farm. Moreover, this improved performance does not require higher individual wind
turbine efficiency, only closer wind turbine spacing and a sufficient vertical flux of turbulence
kinetic energy from the atmospheric surface layer. The results suggest an alternative approach to
wind farming that has the potential to concurrently reduce the cost, size, and environmental
impacts of wind farms.

[Uncle Joe]

1. Kicked and recommended.

Thanks for the thread, Bill USA.

[Bill USA]

40. here's a presentation by Dabiri that explains his work more than the paper sited in OP

http://dabiri.caltech.edu/publications/FLOWE_PPT_Dec2010.pdf

[tridim]

2. What ever happened to the super-efficient piezoelectric turbines that were being developed?

No moving parts seems like the ultimate best solution. Off to google.

[muriel_volestrangler]

3. The PDF comes up blank, for me

The abstract talks about 'potentially' achieving a much greater density. Can you say what they did actually find?

[Bill USA]

4. the pdf is slightly over 30 mB so you have to be a little patient. as far as what they have found

here is John Dabiri's page at Caltech with an email link:

http://dabiri.caltech.edu/people/dabiri.html

personally, if they came up a little short and only bumped up the output say, 5 to 8 times, I wouldn't be too depressed.

[WhiteTara]

9. Potential is no creditial. n/t

[Bill USA]

20. I'm sorry, I thought this forum was for those who are 'up-to' entertaining the "possible" as well as

the already achieved. Is there any nascent technology that does NOT bear the 'burden' of having to be proved? I mean if it is new, isn't it by definition not proven?

Well okay, there are a lot of posts noting what is wrong with our current ways of doing things. But a lot of posts on this forum do point out promising approaches or technologies that the poster may feel warrants investigation. Note, 'promising' means "showing possibility". By definition, it's not already proven. Is it not self evident that there can be no change without trying new things?

It would be nice if all our problems were solved, but alas, we are stuck here in reality where much is less than it could be. But, if that is the case, and we want to improve it, that means trying new, not fully proven techniques and technologies. Without this, there can be no improvement, right?... Unless, of course,... you are going to invoke ..... Devine intervention.(?)

....is there a 'Blind Faith' forum on DU???

[kristopher]

5. The issue of "watts per meter of land area" isn't critical.

Far more important to the development of wind, is the cost per watt. The use of vertical axis wind turbines is limited by the inability to put them high into the air, and by the difficulties associated with increasing the swept area per tower-generator.

This is interesting, and may have some limited applications, but it isn't a significant development even if it delivers 100% of the hoped for 10X increase.

[AtheistCrusader]

46. Our testbed VAWT's have been stationary for most of my life, and now

rust in the shadow of production HAWT's.

Agree that you just can't get them high enough up into strong/steady wind.

[NV Whino]

6. Research such as this is where we should be putting our money

Screw nukes.

[Bill USA]

17. This is an example of why cutting support for eduction and R&D as GOP likes to do is so senseless.

YOu just do not know what you may be losing or at least delaying, who knows - perhaps 10 or 15 years, by not supporting research by smart, imaginative people, of which Dabiri is an example.

This is a signal developement. Dabiri has developed a way of dramatically increasing power output - not by investing in larger, more robust and more expensive equipment. But just by using his brainpower and determining an optimal way to arrange VA turbines to take advantage of the interaction of the wind and turbines. A phenomenon that, before he figured it out, was GOING TO WASTE!

"IF a tree falls in the forest and there is nobody there to hear it, does it make a sound?"

Dabiri heard (and brought to bear some intelligent analysis) while others remained dumb (i.e. not able to hear).

[OnlinePoker]

7. Here's a link to the company that's supplying some of the test towers

They're already in production and have been installed in a few places. Good video on the front page of one in downtown Reno.

http://windspireenergy.com/

[Yo_Mama]

10. A power curve like this surely limits the application?

Not too many sites with that type of windspeed.

[kristopher]

11. The blades aren't sweeping a large enough area.

Increase the blade size and you can compensate for velocity.

[Yo_Mama]

13. How big do they make these?

This is really interesting - I never saw one of these before.

[Bill USA]

14. Not too many sites? check with wind power installation guidelines. the Weibull distribution is

typically used to model the wind speed distribution for sites in most of the world. NOte the chart you provided is a chart of power output for a range of windspeeds (no scale provided)...NOT a chart of windspeed distribution.

NOTE the Weibull distribution (see below) shows that the wind speeds are scewed to the lower end of the range, meaning a greater proportion of the time the winds are in the lower end of the range and spend a smaller proportion of time at the higher speeds (in other words, wind speeds do not fall into a Normal distribution).


Also note that wind turbines have 'cut-out' speeds as well as 'cut-in' speeds. Wind Turbines (especially the large ones) cannot be allowed to spin above certain speeds (that's no doubt why the power curve you show has a drooping dotted line above a certain speed - no scale provided along horizontal axis). As the title to the chart shows it is a chart of Power output per wind speed - not a wind speed distribution chart.

Smaller turbines typically have lower cut-in speeds than the HA Turbines(especially when talking about the bigger ones), meaning they can draw power from slower speed winds. Another advantage to VA turbines they can draw power more easily from winds coming from varying directions.



mean = 6.7 mph


http://www.reuk.co.uk/Wind-Speed-Distribution-Weibull.htm">Learn about the Weibull Distribution which models wind speeds

Wind speeds in most of the world can be modelled using the Weibull Distribution. This statistical tool tells us how often winds of different speeds will be seen at a location with a certain average (mean) wind speed. Knowing this helps us to choose a wind turbine with the optimal cut-in speed (the wind speed at which the turbine starts to generate usable power), and the cut-out speed (the speed at which the turbine hits the limit of its alternator and can no longer put out increased power output with further increases in wind speed).

[Yo_Mama]

27. That graph came from Windspire's website linked above

They were saying average windspeed best 11 mph, should be 10. Not me. This page:
http://windspireenergy.com/windspire/about-the-windspire/

The Windspire® wind turbine was designed to operate in areas with average wind speeds of at least 10 mph (4.5 m/s), although they work best where average winds exceed 11 mph (5.4 m/s).

I understand about the cut-in and the output scaling up as a function of the square of windspeed, I know all about the Weisbull curve, but I never saw a small commercial turbine that required such a high base speed to generate significant power. And yea verily, this graph is like that graph, and is also from that page put up by the manufacturer, so surely relevant:


That's average windspeed. It seems to me that this greatly limits the application.

[Bill USA]

33. the point of the OP was not that VAWT would be our salvation. It is almost always the case that no

one approach will fit all situations. The appropriate attitude is to recognize the value of ideas that enable us to take advantage of the variety of situations presented to us.

The OP noted that a researcher has figured out how to boost the amount of power you can harvest from the wind, not with massive additional investment, but by being smart about how you arrange the turbines (VA turbines). This presents the possibiliy of harvesting wind power from sites that are not suitable for large HAWTs. This opens up the possibility of siting wind farms closer to the final power consumer.

The closer your wind farm is to the final consumer the lower your transmission line losses will be. In the power supply business, with margins extremely tight, this is of interest.

This is not a matter of one idea (VAWTs vs HAWTs) being 'better' than another.

[kristopher]

36. You still have it wrong - this isn't rocket science.

You wrote, "The OP noted that a researcher has figured out how to boost the amount of power you can harvest from the wind, not with massive additional investment, but by being smart about how you arrange the turbines (VA turbines)."

Being "smart about how you arrange the turbines" saves nothing in the way of costs. In fact, it probably increases the costs.

You can increase production by making the turbin larger or you can increase production by making more turbines.

1) When you make them larger, the footprint on the ground grows almost not at all. When you make more smaller ones, you INCREASE the footprint on the ground. This means that land for a larger turbine can be dual use (agriculture, grazing etc) but if you pack a bunch of smaller turbines into the same area then you lose the dual use nature of the land and consequently will pay more to use the land.
Net cost increase.

2) If I start with a 100KW turbine and then build 19 more 100kw turbines to get to 2MW, it will cost more to build 20 foundations, 20 rotor assemblies and 20 generators than it will to build 1 larger tower, 1 larger generator, and 1 larger rotor assembly. A LOT more.


Unless there is a critical lack of space, the savings afforded by the research in the OP is not consequential.

[txlibdem]

29. Here's a wind speed map of the USA, based on Weibull

http://windeis.anl.gov/guide/maps/map2.html

[Gregorian]

8. Amazing stuff.

Don't laugh, but this is exactly the kind of stuff I used to think about as a kid. Ways of using the turbulent flow "shadow" in useful ways. Well this is one amazing combination of concept and technology.

It just reinforces how silly it is to be spending MASSIVE amounts of money with the Pentagon.

[txlibdem]

12. Vertical Axis turbines are far more tolerant of turbulence than the Horizontal Axis turbines

Horizontal Axis Wind Turbines suffer greatly reduced energy output due to turbulence and if it gets bad enough it can rip the turbine blades apart.

Vertical Axis Wind Turbines should be a big part of our wind energy plan due to that fact alone. The increased output by careful placement is just icing on the cake.

As to the complaint that vertical axis turbines are "too small," check out this one that produces as much energy as 150 horizontal wind turbines:
http://www.youtube.com/watch?v=k1ClVC08kes

[Bill USA]

15. Here's a Horizontal Axis Turbine that will blow your mind 100 - 1,000 KW

http://www.mechanicalengineeringblog.com/1897-mars-floating-wind-turbines-horizontal-axis-wind-turbine-lowest-cost-wind-energy-solution-how-floating-wind-turbine-works/">MARS Floating Wind Turbines - Horizontal Axis Wind Turbine - Lowest Cost Wind Energy Solution - How Floating Wind Turbine Works


..and..http://www.magenn.com/">There is enough energy in high altitude winds to power civilization 100 times over; and sooner or later, we're going to learn to tap into the power of winds and use it to run civilization." Says Ken Caldeira, Professor of Global Ecology at the Carnegie Institution for Science. (Discovery Channel, Project Earth, Infinite Winds episode)

of course this isn't using the grouped VA tubine concept arranged to capture and use turbulence. This approach is just MEGA-wind capture.

[Yo_Mama]

28. I've been looking at these

This is a very interesting time to be alive.

[kristopher]

16. That is woo woo nonsense on its face

You wrote, "As to the complaint that vertical axis turbines are "too small," check out this one that produces as much energy as 150 horizontal wind turbines".

The Power of Wind
Wind is made up of moving air molecules which have mass - though not a lot. Any moving object with mass carries kinetic energy in an amount which is given by the equation:

Kinetic Energy = 0.5 x Mass x Velocity2

where the mass is measured in kg, the velocity in m/s, and the energy is given in joules.

Air has a known density (around 1.23 kg/m3 at sea level), so the mass of air hitting our wind turbine (which sweeps a known area) each second is given by the following equation:

Mass/sec (kg/s) = Velocity (m/s) x Area (m2) x Density (kg/m3)

And therefore, the power (i.e. energy per second) in the wind hitting a wind turbine with a certain swept area is given by simply inserting the mass per second calculation into the standard kinetic energy equation given above resulting in the following vital equation:

Power = 0.5 x Swept Area x Air Density x Velocity3

where Power is given in Watts (i.e. joules/second), the Swept area in square metres, the Air density in kilograms per cubic metre, and the Velocity in metres per second.

http://www.reuk.co.uk/Calculation-of-Wind-Power.htm

Achieving the 20 MW Wind Turbine
By Jos Beurskens, Netherlands Energy Research Centre (ECN)
June 3, 2011

Significant additional research efforts in wind energy are needed if the European Commission's goals for wind power are to be achieved. It will mean delivering EWEA's 'high' scenario: 265 GW of wind power capacity, including 55 GW offshore, by 2020; 400 GW, of which 150 GW is to come from offshore, by 2030; and 600 GW, with 350 GW offshore, by 2050, meeting 50% of the EU's electricity demand. Going offshore implies not only new technologies but also an upscaling of wind turbine dimensions and wind farm capacities as well as new electrical infrastructure. Underlying all research activities is a focus on reducing the cost of energy.

The industry is taking two parallel pathways towards cost reduction: first, incremental innovation, looking at cost reductions through economies of scale resulting from increased market volumes of mainstream products, with a continuous improvement of manufacturing and installation methods and products; secondly, breakthrough innovation, focused on creating innovative products, including significantly upscaled dedicated offshore turbines, to be considered as new products.

Funded under the European Union's Sixth Framework Programme (FP6), the UpWind project has been exploring both pathways. The UpWind project initiators realised that wind technology disciplines were rather fragmented, in that no integrated verified design methods were available; that essential knowledge was still missing in high priority areas, for example in external loads; that measuring equipment was still not accurate or fast enough; and that external factors were not taken into consideration in minimising cost of energy (grid connection, foundations, wind farm interaction and so on).

Optimum Technology?

Rather than pursue one single 'optimum' technology, UpWind explored various high-potential solutions and integrated them with a view to the potential reduction of cost of energy. An optimised wind turbine is the outcome of a complex function combining requirements in terms of efficiency of electricity production, reliability, access, transport and storage, installation, visibility, support to the electricity network, noise emission, cost, and so forth. UpWind's focus was the wind turbine as the essential component of a wind power plant. Thus external conditions were only investigated if the results were needed to optimise the turbine configuration...

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x299120

[Bill USA]

18. Actually, I was quoting Ken Caldeira, Stanford University. Here's more from Caldeira

your quote is from analysis of low level winds and probably quite accurate. I was pointing out to txlibDem the imaginative, even amazing ideas proposed by some. but I don't think any of these approaches are close to realization (well, maybe those of MAGENN are, don't really know). ...unlike the approach developed by Dabiri mentioned in OP.

But the more ambitious ideas I don't believe need to be rejected out of hand. They are worth being pursued by those people intelligent enough to devise them.

Caldeira is talking about high level winds, a whole different ball-game than close level winds. THese ideas are certainly stretching the envelope and may not be technically feasible at the moment.

http://news.stanford.edu/news/2009/june24/high-altitude-winds-062309.html">High-altitude winds: The greatest source of concentrated energy on Earth

[kristopher]

19. My response wasn't to you.

You have also completely misinderstood the post upthread by Yo mama. VAWTs are not and are not going to be a significant part of our energy infrastructure.

I like the idea of high altitude wind, but significant materials development is required before it is even considered as a potential resource.

[Bill USA]

21. my response to YoMama? did you read it, or incapable of understanding a simple point.

the Weibull distribution applies to wind speed distribtion (although the chart he showed was not of wind speed distribution, he thought it was) but of power output for a range of wind speeds.

Since wind turbines either VA or HA are designed to not to keep spinning above a certain speeds at the higher wind speeds one would expect a power drop off (the dotted line in his chart).

This was a simple and straight-forward correction of his confusion. Though, I doubt you still 'get' it.

[kristopher]

22. Yo mama wasn't confused.

You are. The graph is indeed a plot of the output of the turbine.

That output is determined by wind speeds.

The wind speeds required for tht turbine are high.

The wind speeds required are high because the mass of air passing across the turbine blades is small.

Low amounts of mass in motion equals low embodied kinetic energy.

You can increase the energy available by 1) increasing velocity or 2) increasing the size of your collection area (larger blades).

You can increase velocity by moving higher and away from the layer of air that is slowed by dragging across the ground.

You can increase swept area by making larger rotors or building more turbines.

Two of those three options (rotor size and height) do not work for VAWT; they are the "limiting factors" for the technology.

The third option of more turbines and thuse more bladed area, increases costs far more rapidly than taller towers and longer blades.

That makes cost the limiting factor in that direction.

[Bill USA]

24. Yo' is confused, since you don't seem to understand what I said.

you state: "The graph is indeed a plot of the output of the turbine."

Which is what I said it was. You seem to think your statement contradicts what I said. It doesn't. It confirms what I said.

your statements re wind speed etc show you haven't grasped the whole point of what Dabiri is doing. Your observations pertain to a wind turbine in isolation. they are not necessarily wrong, just not considering at all what Dabiri is doing. His paper really is worth the read (if you are into reading source documents).


... the whole point of Dabiri's study is to see how much power can be generated from a given area of land by grouping VAWTs closely and in a particular arrangement to take full advantage of the wind, even as it flows away from adjacent counter-rotating turbines.

from Dabiri:

"The overall approach described presently is fundamentally different from current practices in
wind energy harvesting: here, a large number of smaller VAWTs are implemented instead of
fewer, large HAWTs. The higher levels of turbulence near the ground — both naturally occurring
and induced by the VAWT configuration — enhance the vertical flux of kinetic energy delivered
to the turbines, thereby facilitating their close spacing. This approach has the potential to
concurrently alleviate many of the practical challenges associated with large HAWTs, such as
the cost and logistics of their manufacture, transportation and installation (e.g. by using less
expensive materials and manufacturing processes, and by exploiting greater opportunities for
mass production); environmental impacts (e.g. bird and bat strikes); acoustic and radar signatures
(e.g. lower tip speed ratios than HAWTs, 2); visual signature (Figure 10); and general acceptance
by local communities. These issues, although not strictly scientific, limit the further expansion of
existing wind energy technology."



He states in the 'results' section of his paper:

"The calculated power density for a VAWT farm with these parameters is approximately 18 W m-2 (cf. equation 2). This performance is 6 to 9 times the power density of modern wind farms that utilize HAWTs (14).

Furthermore, it is straightforward to compute combinations of VAWT rated power output and turbine spacing that can achieve 30 W m-2 (i.e. 10 times modern HAWT farms) by using 1.2-m diameter VAWTs like those studied here (Figure 7)."

[kristopher]

25. See posts 5, 11, 16, 19, and 22.

The errors in your post have already been explained.

[Bill USA]

26. see Dabiri's paper, read. will quiz you later. Specific information beats generalities

every time. Unless of course you're bullshitting.

Claiming I made utterances in error, without being specific, is laughably pitiful and the resort of a bullshitter.

As I said before, your statements may be true as generalities but you are hiding behind these because you won't or can't comprehend that Dabiri etal have developed a special case involving closely positioned turbines that affects the airflow to adjacent turbines.

For the readers, I paste the following as an antidote to your bullshit which is stinking up the whole area.


http://dabiri.caltech.edu/publications/WhLiDa_BB10.pdf">Fish schooling as a basis for vertical axis wind turbine farm design


Robert W Whittlesey1, Sebastian Liska1 and John O Dabiri 1,2

1 Graduate Aeronautical Laboratories, California Institute of Technology, 1200 E California Blvd,
MC 205-45, Pasadena, CA 91125, USA

2 Option in Bioengineering, California Institute of Technology, 1200 E California Blvd, MC 205-45,
Pasadena, CA 91125, USA

"....when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient.
In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely spaced VAWTs may
experience only small decreases (or even increases) in an individual turbine’s power coefficient
when placed in close proximity to neighbors, thus yielding much higher power outputs for a
given area of land. A potential flow model of inter-VAWT interactions is developed to
investigate the effect of changes in VAWT spatial arrangement on the array performance
coefficient, which compares the expected average power coefficient of turbines in an array to a
spatially isolated turbine. A geometric arrangement based on the configuration of shed
vortices in the wake of schooling fish is shown to significantly increase the array performance
coefficient based upon an array of 16 × 16 wind turbines. The results suggest increases in
power output of over one order of magnitude for a given area of land as compared to HAWTs."

...note the words "which compares the expected average power coefficient of turbines in an array to a
spatially isolated turbine"....cf my comment re same(above #24 "Your observations pertain to a wind turbine in isolation.").

[txlibdem]

23. Who do the "woo woo" that you do?

UpWind Project: I also have an OP that talks about the 20 MW horizontal axis wind turbine. This isn't (in my mind) an ideological battle where there can be only one winner. I'm all for the 20 MW wind turbine. I've stated it many times: there is NO silver bullet that will end the reign of fossil fuels. That means that vertical axis *and* horizontal axis wind turbines are needed.

The equations that you copy-pasted do nothing to argue your point: Power = 0.5 x Swept Area x Air Density x Velocity3

The video that I posted shows a magnetically levitated vertical axis wind turbine that is huge enough that the helicopter shown landing on its "roof" is dwarfed in comparison. Then the air scoops effectively triple the swept area, funneling the air into the turbine blades. We do not know the swept area, nor the wind velocity, nor the air density so how can your equation prove anything?

[txlibdem]

30. MagLev vertical axis wind turbine that would produce as much as 150 "regular" wind turbines

Check out this one that produces as much energy as 150 horizontal wind turbines:
http://www.youtube.com/watch?v=k1ClVC08kes

Exact dimensions are not given but it looks like at least 150 feet tall and about 100 feet wide, plus the wind diverters basically triple the area of wind that it collects. And it all rides on magnetic fields so there are no gears or wasted energy from bearings, no oil that needs to be changed like regular wind turbines.

[kristopher]

31. Yes, you're much smarter than all those stupid people foolishly....

... spending billions building wind farms with those dumb old horizontal axis wind turbines.

You are going to be so rich because you have it all figured out; hell you even have a youtube to show the investors.

Congratulations.

[txlibdem]

32. Your sarcastic and snide remarks tell me that I'm on the right track - thanks

You've proven me right again.
:woohoo:

[Bill USA]

35. Have been in touch with Dabiri.

He indicated they are working on a prototype VA wind turbine which will surpass in efficiency anything commercially available now. Once that is done, work will begin with larger scale installations.

Thought you'd find this interesting. (more via pm).

[Bill USA]

34. typically, your pre-adolescent attitude condemns you to missing the point entirely.

This is not a matter of who's idea is 'better' than the other. In other words, it's not a case of "My dad can beat up your dad!".

It is about being able to reap the benefits of ideas which enable us to take advantage of the various situations presented to us. It is almost never the case in technological developement, that one approach reigns supreme over all others - in all situations. It is more likely that we have to adapt our approach to solving a problem based on the situation presented to us.

There are situations to which large HAWTs are not well suited. It's possible that VAWTs will be able to take advantage of situations not so well suited to HAWTs and enable us to harvest the power of the wind in places where HAWTs could not be used. This researchers work (see OP) which increases the amount of wind generated power that can be harvested from a given land area, will no doubt make this more likely.

Again, this is not about 'whose dad can beat up whose dad'. The challenge of gleaning the power of ideas to increase our yield of power from the wind is really one for grownups to pursue.

[kristopher]

37. It isn't personal or pique;

...it is just a matter of you claiming there is a significance to the research that isn't there.

Here is the challenge you face. Show how building 20 100KW turbines with a 40 ft hub height (spaced any way you wish) is less expensive and more productive than building one 2MW turbine with a 260 ft hub height.

From there, if you wish, show how the economics of two 60MW wind farms would compare, one with small, short wind turbines spaced close together, and one with the 2MW turbines spaced as appropriate to the technology.

The electricity from the 2MW will be substantially less expensive in both cases.

Substantially.

Grow up.

[stuwis]

38. Answer to the challenge

Here are a few ways that several smaller VAWT's can be more productive than one large 2MW HAWT

1) Small VAWTs can go where large HAWTs can't (ie, permitting)
HEIGHT - Most cities/towns have a 35' height restriction, thus making the 400' height of HAWTs untenable
NOISE - Most VAWT's generate less than 35 dB at 30', whereas large HAWTs generate 120-150 dB at over 200'
SET BACKS - VAWT's typically have a set back from the property line of the height of the pole (less than 40') whereas large HAWTs have set backs of 1/4 mile to one mile
ENVIRONMENTAL CONCERNS - Large HAWTs kill birds and bats (and while I agree that this issue is blown way out of proportion - millions of birds die in collisions with plate glass versus tens of thousands in turbine deaths), regulating authorities see it differently. VAWTs, because of their low rpms, do not.

2) VAWTs can go on rooftops -while technically part of #1, the fact is that small VAWTs can be mounted on commercial roofs, giving them access to the higher wind speeds and wind powers which large HAWTs.

3) ECONOMICS -
POWER RATE - While a large HAWT provides utility scale power, and thus is paid a utility scale rate, small VAWTs provide power for homes,offices and shopping centers. Since they work on 'net metering', they effectively earn the same rate as the retail rate of the power company. The difference between the two can be hundreds of percentile points in difference
REBATES/INCENTIVES - Many states, such as CA offer a greater tax incentive for small wind than large wind (under 30kW receives $3/kW while 30kW to 5MW receives $1.50/kW).

I'll grant you that #3 still does not outweigh the quantity factors most of the time, but the fact that small VAWT projects can go where large HAWT projects cannot means that, regardless of what the ROI of the VAWT project, it is always better than 0.

[kristopher]

39. That's a reasonable attempt.

But it is somewhat lacking in rigor. My assessment can be summarized by this quote, "VAWTs are not and are not going to be a significant part of our energy infrastructure."

I wrote that in response to exaggerated claims about the significance of this research.

I took the time to make the point because the exaggerated claims have a specific purpose when viewed as misinformation.

When astroturf opposition to wind farm siting is trying to generate local opposition they know the psychology of the public. Almost everyone is in favor of wind generally, and the astroturf campaign is faced with trying to influence these people to reject a specific project. Part of that process is to provide a rationalization that can work to relieve the cognitive dissonance that would otherwise present itself if a "nimby attitude" is to be cultivated.

Here is an example of how it works:
Mr. Moderate is an amiable sort that doesn't really like confrontation, but he's friends with Ms. Righty that listens to local right-wing radio religiously. Mr. Moderate thinks the proposed wind farm outside of town is a pretty good idea; clean, cheap energy and jobs are things that are difficult to object to, after all. But Ms. Righty sees it as a lib'rul conspiracy to waste taxpayer money with huge industrial machines that "chew up birds" and "ruin the beautiful pristine landscape" along the interstate. She insists that if we'd just drill for the oil she knows is there and get the fascist EPA off the backs of honest businesses we wouldn't have an energy problem.

Mr. Moderate doesn't for a second buy into Ms. Righty's world view, but he really doesn't like butting heads with her either and she is a terror anytime the wind farm is brought up - which is something she makes sure happens every chance she gets.

Then one day Mr. Moderate reads on website of the "local" citizen's group "SAVE OUR INTERSTATE FROM INDUSTRIAL WIND" of the plausible sounding but actually economically unworkable VAWT concept that they are proposing as an alternative.

Based on that mischaracterization, Mr. Moderate signs their petition to oppose the project that he actually likes; after all, this certainly sounds better, and it aligns him with his good friend in opposition to the one that has her so agitated. Conflict in his personal life is minimized and he is true to his beliefs.

No wind farm is developed.


That scenario might sound strained, but after two years of doing in depth interviews with stakeholders in wind projects at all levels, I can assure you that is how it is being played.

[stuwis]

43. You seem to be missing a bigger point

And no offense, but your answer is even more lacking in rigor than mine.

While the claims of the research may well be exaggerated, your blanket statement about VAWTs versus HAWTS has no rigor at all.

I stated clearly that the bird and bat kills are a red herring. For what its worth though, that does not matter. If you want to do research, you will find that study after study has found no deleterious effect to living near power transmission lines, yet real estate prices drop significantly the closer a home is situated to them. Much more so than other similarly visually unappealing locales. There are many instances when perception becomes reality, whether it is so or not.
Bird or bat deaths related to turbines is miniscule and dropping. That said, if one starling a day flies into the plate glass of your office building and dies, no one notices. But if a flock of starlings flies into the air pocket of a large VAWT and 30 of them die, it makes the 6 o'clock news. Is that fair? No. Is it true? Yes.

But on the larger picture, the point you seem intent on missing is the difference between Utility Grade Power and Individual Power. All the large HAWTs in the world do not make MY power bill go down by one cent. But if I install a turbine on my property, then I do have a reduction in MY power bills. While the cost per kWh may be significantly higher and the return may be significantly lower than that of a public utility buying power from a large wind farm, it is only my ROI that I am concerned with.

So then the question of VAWTs becomes one of competition with other forms of personal power and whether personal power will Ever (your word) become a significant part of our energy infrastructure. Since the VAWTs are competitive with solar in many cases (even with the extra tax advantages solar gets relative to wind in most cases), and since the percentage of homes and businesses installing small wind or solar systems continues to grow rapidly, I believe you are incorrect in your assertion.

Large HAWTs are PART of the answer to our energy issues, not THE answer. So to are VAWTs, Solar, Geothermal and the rest. Big Wind, Small WInd, Solar, and so on should be trying to help each other instead of fighting over whatever piece of the pie they are treying to garner. Not every situation is right for any one type of renewable energy generator.

I must say that while you may criticize NIMBYism, I feel you are engaging in My Answer Is The Only Answer- ism.
Respectfully, I must strongly disagree.

[Bill USA]

41. Other factors, when you are putting your wind farm far from demand centers, are transmission losses

and the cost of (and logistics of installing) transmission lines.

Right now, the biggest bottle-neck for wind power is the installation of new power transmission lines, especially from the prime wind sites. But also, remember that line losses are not insignificant in the very narrow margin business of electric power generation. When you start transmitting more than a few hundred miles, this can eat into your energy delivered, and your ROI. Long distant power lines are not cheap and getting them installed takes a considerable time.

If you can build a wind farm close to demand centers, your line losses are virtually nil, and power lines are aleady there and more accessible. Yes, more lines might in some cases be needed, but at least the clearances have already been met since you would likely be adding capacity to already existing transmission corridors.

http://www.usatoday.com/money/industries/energy/environment/2008-02-25-wind-power-transmission_N.htm">Wind energy confronts shortage of transmission lines

....Stringing new wires is easier said than done. Wind developers won't go ahead with projects until transmission lines are in place, and utilities are loath to build the lines until they're sure the developers won't back out. Also, the first wind developer in an area is often asked to shoulder much of the $1.5 million-per-mile cost of a high-voltage line.
~~
~~
In southwest Minnesota, dozens of wind projects have been proposed to serve the Twin Cities. Even if just 30% of them, with 7,500 megawatts of capacity, are developed, that would far outpace the 2,000 megawatts of transmission capacity planned.

Similar bottlenecks are stalling wind farms in the Midwest, Southwest and California. Compounding the standoff: Some states don't want residents paying for lines that will largely benefit neighboring states. As a result, utilities in several Midwestern states may not meet mandates for clean energy to make up about 20% of their energy mix by 2020, says Clair Moeller, an executive for the Midwest grid operator.

Xcel Energy, a Midwest utility, says it can't raise money for transmission lines that might not carry any juice. "You're committing $1 billion in capital in the hope the cost recovery will come, and that's a tough proposition," says Paul Bonavia, head of Xcel's utilities group.

http://www.nytimes.com/2011/01/21/us/21tttransmission.html">Lack of Transmission Lines is Restricting Wind Power

The oilman T. Boone Pickens, for example, bet heavily on wind a couple of years ago, ordering hundreds of turbines and announcing plans to build the world’s largest wind farm in the Panhandle at a cost of up to $12 billion. He later scaled back, canceling some of the turbine orders, giving up his land lease and saying he was looking elsewhere to build.

To encourage others, the state is moving forward on a contentious project to erect $5 billion worth of transmission wires to connect the turbines to the cities that need power. On Thursday, state regulators met in Austin and approved the route of a controversial line that will run about 140 miles through the Hill Country, one of the state’s most scenic regions.

Construction of the line — a project of the Lower Colorado River Authority that will run from Schleicher County to a substation near Comfort — should start next year. Last year, vigorous opposition, by landowners, wealthy newcomers and old-time families, succeeded in derailing plans for another line that the state had wanted to build through the area.

Of course, nothing in my OP ever implied this is a case of one idea being "better" than another (that somebody - anybody - would take it that way is a surprise to me!). This is a case of someone's research creating a resource where there was none before, by enhancing the productivity of VAWT farms. Dabiri's research will make wind farms close to demand centers more productive. What is interesting is he is achieving an order of magnitude increase in output per unit land area, just by how he positions the wind turbines. Pretty clever, if I do say so myself.

Here is a presentation by Dabiri, that goes into his research in a little more detail. Thought you would find this interesting.

http://dabiri.caltech.edu/publications/FLOWE_PPT_Dec2010.pdf


Not too bad ....for a Professor of Aeronautics and Bioengineering at California Institute of Technology, a MacArthur fellow and a graduate of Princeton University(summa cum Laude) in Mechanical and Aerospace Engineering.

[kristopher]

42. The "Professor of Aeronautics and Bioengineering at California Institute of Technology, a MacArthur

... fellow and a graduate of Princeton University(summa cum Laude) in Mechanical and Aerospace Engineering" isn't mischaracterizing the significance of the research; you are.

Your points about "line losses" are not particularly relevant, since the issue you base them on doesn't exist. If the advantage for the VAWT is a local land use issue, that can be addressed with an alternate nearby location - going 20 miles or so can usually have a big impact on those types of issues. If the issue is wind availability, in almost all cases the HAWT is going to perform better because of the greater altitude of the blades and its lpwer marginal cost for increasing the swept area.

Any way you slice it, small scale wind (HAWT or VAWT) is only very rarely a good choice for grid related applications. The economics just aren't there no matter how much you want to believe they are.

[stuwis]

44. Another Wrong Blanket Statement

"Any way you slice it, small scale wind (HAWT or VAWT) is only very rarely a good choice for grid related applications. The economics just aren't there no matter how much you want to believe they are. "

For a home or business, large wind is not just impracticable it is impossible. So if your only concern is for the public utility companies, then your answer has merit. But if you are considering the case of the person or company looking to reduce their bill and contribute to cleaner energy, then small wind is certainly a good choice.

No matter how much you want to believe it isn't

[kristopher]

45. The study is about building a commercial wind farm, not homeowners.

Also, why isn't everyone off the grid right now? The technology has been there for decades.

The reason most people are still grid tied, is because of economics. They are unwilling to pay 4X-10X the cost of grid electric. That is still the case with small wind, this study changes nothing in that regard. You can disagree as strongly as you wish, but the physics of rotor size, wind speed and altitude don't really care.

[stuwis]

47. Article is about multiple units - not neccessarily commercial wind farm

20 10kW units would not usually qualify as a commercial wind farm, but would certainly fall well within the parameters of the article.

People are grid tied because of ease, custom as well as economics.
Net Metering laws have only been recently introduced in most states, and the rate at which people and businesses are signing up for small renewable systems is growing almost exponentially.

And the physics of rotor size do not make a difference, except in cost. As to wind speed and altitude, I will repeat - small VAWT's can be placed on commercial building rooftops, leveling the playing field for those two - AND in places where large VAWTs cannot go, reducing the costs of substations, transmission costs and grid improvements.

It seems that you are determined to be 'right' regardless of any facts to the contrary. I wonder why that is? You can keep pretending that large HAWTs are always the solution, but that is just as one-sidely blind as those that claim nuclear is always the answer, coal, oil, solar or any other single solution.

Large HAWTs have a place, but so do other technologies. Only myopia would prevent one from agreeing with that self-obvious statement.

[Bill USA]

48. So you're saying Dabiri devoted some years of his life to research that is of little significance

.... and that the research funding committee at the California Institute of Technology approved a not insignificant amount of money to support research that is of little significance. Presumably, they should have consulted you to gain from all your expertise in these matters. :rofl:

....and you say you are NOT trivialising Dabiri's work.

For my part, I merely reported on Dabiri's work. I did not attribute more significance to his work than what has already been recognized by others. The title to the OP was lifted from the title of the article I referenced. The title merely paraphrases John Dabiri's own words in his paper: http://dabiri.caltech.edu/publications/WhLiDa_BB10.pdf">"The results suggest increases in power output of over one order of magnitude for a given area of land as compared to HAWTs" (FYI: 'one order of magnitude" means 10 times greater)

You seem to think there is some sort of 'battle' between VAWTs and HAWTs (this is not a case of the 'Hulk' battling Superman for supremacy of the CD comix world). You are reading intentions on my part that do not exist. I do not think VAWTs will put HAWTs 'out of business'. That's ridiculous. Dabiri's findings hold the promise of making sites suitable for harvesting wind power using VAWTs that would not be feasible using HAWTs. There is nothing in anything I said that implies HAWTs will replace VAWTs. You are reading motivations into my comments that aren't there.


Now, regarding line losses, and cost of installing new transmission lines, as not being relevant and the conditions I referrred to as "not existing" observe:

1. Location of the wind farm relative to power transmission lines is a consideration:
http://www.awea.org/learnabout/publications/upload/Ten_Steps.pdf">10 Steps to Developing a Wind Farm - AWEA

2. How Far Is Your Site from Existing Transmission Lines? A critical issue
in keeping costs down in building a wind farm is minimizing the amount of
transmission infrastructure that has to be installed. High-voltage lines can cost
thousands of dollars per mile. Whenever possible, availability and access to
existing lines should be considered in selecting a site.

...note that I mentioned the cost of putting in new transmission lines is a factor to be considered and that distance of the wind farm from the final consumer is significant.


2. And with particular attention to line losses:

http://www.ehow.com/info_8368051_wind-turbine-selection-processes.html">Wind Turbine Site Selection Processes

Grid Connection
In general, the longer an electrical wire between a power source and its destination, the more energy is lost moving the current. This phenomenon is known as line loss and is another factor for consideration when selecting a wind turbine site. A site can have ideal ground and wind conditions but be so far from the grid or a power load that connecting it would both be quite expensive and involve the loss of considerable amounts of energy in the line. Batteries are sometimes used in very remote locations to store the energy created by turbines for local use, but in cases where local use is negligible, a good site without easy access to an electrical grid is not a wise choice.

...and again, from siting considerations from AWEA:


http://www.awea.org/learnabout/publications/upload/Ten_Steps.pdf">site selection process - AWEA

1. Understand Your Wind Resource. The most important factor to consider
in the construction of a wind energy facility is the site's wind resource. A site
must have a minimum annual average wind speed in the neighborhood of 11-
13 mph to be considered. Local weather data available from airports and
meteorological stations may provide some insight as to averages. You can
also check the wind maps for your state on the National Renewable Energy
Laboratory Web site. Eventually, you will want to install your own monitoring
devices to record the site's wind characteristics. A listing of consultants
specializing in wind resource assessment can be found at the American Wind
Energy Association Web site: http://www.awea.org/directory/consultcde.html.
More information on basic principles of wind resource evaluation can be found
at http://www.awea.org/faq/wwt_basics.html.

NOTE that they stated: "A site must have a minimum annual average wind speed in the neighborhood of 11-
13 mph to be considered."


Now, look at the U.S. Wind Resources map


Let's consider the violet and red areas as offering the best land based resources (although the map indicates violet as 9 mph average annual wind speed and red as being 10 mph) for wind power. Offshore sites provide even stronger winds but off-shore sites present other transmission line chanllenges of their own. I think anybody can see that the violet and red colored areas are at considerable distances from most population centers. Now, these are NOT the ONLY places where wind farms can be profitably sited but these are the places with the strongest winds (for land based installations). So to say conditions which present line losses as a factor to be considered do not exist is not accurate.

http://www.windpoweringamerica.gov/wind_maps.asp">U.S. Wind Resource map article

you will note that I provided two newspaper articles which reported on the fact that Wind Power's biggest hurdle to clear now is the cost and logistics of installing transmission lines. Maybe you should call up the authors of these articles (not to mention T. Boone Pickens) to tell them these conditions (wind farms situated at considerable distance from the demand) 'do not exist'.:rofl: