Location location, location: Wind Turbine Power Output Increased 10x

Wind Turbine power output is increased ten-fold by careful spacing, and direction of rotation, when compared to existing best practices.

FLOWEClick image for video surveyGuest post by Roger E. Sowell

Summary:  A new study from CalTech shows that wind-turbine spacing, location, and direction of rotation can increase average power output per acre (hectare) by ten-fold, compared to existing best practices.   Professor John O. Dabiri of California Institute of Technology (CalTech) published a paper describing the impact on power production of spacing, location, and direction of rotation on vertical-axis wind turbines.

For images and video, see http://dabiri.caltech.edu/research/wind-energy.html

A preprint of the paper is available at http://dabiri.caltech.edu/publications/Da_JRSE11.pdf   (675 kB)

VAWT (vertical axis wind turbines) that are spaced approximately 4 diameters apart, with adjacent VAWTs rotating in opposite directions, yield a ten-fold increase in power output per unit of land area, from 2 – 3 Watts per square meter of land, to 21 –  47 Watts per square meter when compared to modern horizontal-axis wind turbines.

This has great implications for new wind-farm projects, especially the economics and environmental impacts.  It does not, however, address the Achilles heel of wind power, the intermittency of power production and the need to time-shift power production by some economic means of grid-scale storage and discharge.

From Dr. Dabiri’s paper:

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.

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Don’t VAWTs have their own problems, besides being ugly?

Bruce

VAWT rated power = 0.0012MW
HAWT rated power – 2.5MW or 3MW.
Is it just me or is this study comparing tiny little toy wind turbines to real full sized ones?
Aren’t Mythbusters usually surprised by the results when they go from models to full size?

DirkH

They are also much better against avian critters.

Pretty cool stuff. I’ve always liked VAWT’s better than HAWT’s for their less clumsy design appearance, but believed them to be less efficient. Clustering them like this study suggests with the counter-rotation on adjacent turbines is a smart move. Now they need to work out how to keep birds away from them and keep the noise down. 30W/m^2 isn’t a lot of power for crowded islands like Britain though, and the intermittent wind problem isn’t going away anytime soon with few places suitable for pumped storage and battery technology too expensive.

DocWat says:
July 16, 2011 at 2:13 pm (Edit)
Don’t VAWTs have their own problems, besides being ugly?

These look quite good I think:
http://www.quietrevolution.com/gallery.htm

DirkH

Birds produce CO2. CO2 evil. Die Birds Die! (That’s German for “The, Birds, The”)

Mike McMillan

The vertical axis turbines are less efficient than the current crop of windmills, but their increased density ‘overcompensates’ for this by gleaning the wake of upstream turbines. We get better output per unit of land, but increased density means more turbines, which means more capital cost. We’ll have to wait to see how this scales up in terms of cost/output and nuisance noise generation.

Hu McCulloch

I remember reading about “egg beater” windmills 30-40 years ago. A big practical advantage then was that the generators are at the bottom, where they don’t need to be supported and are easy to service, rather than at the top.
DirkH — By “much better” with birds, do you mean they are better for the birds or do a better job of annihilating them?
I can see a man in the picture. Are these production sized or scaled down?

Curiousgeorge

Zero times 10 is still Zero when the wind don’t blow.

John F. Hultquist

This sounds great.
Then the wind doesn’t blow.
Ten times zero equals zero.
Next?

Doug in Seattle

GE invested in the wrong technology? All those factories they built in China will now have to be re-tooled – oops. No problems though, Obama will just write another check once he gets the credit limit increase.

Tip speeds are much lower with VAWT’s, so noise is less of an issue.

Richard S Courtney

Wind turbines provide intermitent power so when they do operate to produce electricity to a grid they merely displace thermal power stations onto standby (with no reduction to fuel consumption and emissions) or onto part loading (with increased fuel consumption and emissions). The thermal power stations need to keep operating like that until the wind turbines stop operating.
In other words, wind tubines do not provide any useful electricity to a grid at any time.
Ten times nothing useful is nothing useful.
Richard

DirkH

Hu McCulloch says:
July 16, 2011 at 2:57 pm
“DirkH — By “much better” with birds, do you mean they are better for the birds or do a better job of annihilating them? ”
I said “much better against”. Here in Lower Saxony, there’s an area full of wind turbines, or rather lots of them, for instance two huge concentrations around Kraftwerk Mehrum and near Salzgitter-Lebenstedt and then there’s also the beautiful Innerste valley south of Hildesheim. It’s wind turbine free as, being a narrow valley, not very windy. I saw the most beautiful birds of prey there; a red milan being the most spectacular. Birds i didn’t see near the wind turbine fields. Now, that might all be a coincidence but i’m driving a lot through these regions…

Mark Wagner CPA

Having just returned from a trip though West Texas, I was appalled by the 5,000+ turbines on every flat spot northwest of Abilene.
They are an abomination and a blight upon our land.

u.k.(us)

I have never walked through a coal or nuclear power plant, to get an appreciation of our engineering prowess, and the scale of our power production facilities.
I think “the children” should be exposed to the infrastructure that keeps their electronics running, maybe then they will realize the folly of windmills.

dp

There are some crazy numbers being thrown around, here, with no qualification. For example – the following represents delivered power on average, or power capability?
VAWT rated power = 0.0012MW
HAWT rated power – 2.5MW or 3MW
A 2MW turbine that limps along at 7% of capability is producing very little power per acre.
Then there is the density question. It is claimed that a certain acreage is required per generator, as a design goal. This is probably the talked about acreage requirement. Then there is the as-built acreage – what is actually happening in the world of wind farm construction.
Here at Mark Lynas’ blog I link some information regarding the as-built:
http://www.marklynas.org/2011/04/how-much-of-japans-land-area-would-be-needed-to-replace-nuclear-with-wind/
And which I’ll link here as well, as it is interesting to see the differences between what can be done and what is being done.

Here’s some data on what is already built.
http://www.aweo.org/windarea.html
And the conclusions (section 6) of this document found on the calculator page Romm’s article referenced, the 1.2 million acres is pretty close on an area/MW basis using 1MW generators:
http://www.nrel.gov/docs/fy09osti/45834.pdf
In Washington State the new Kittitas eyesore sites 52 400′ towers on 5,400 acres.
http://www.efsec.wa.gov/kittitaswind.shtml

Kev-in-Uk

maybe in conjunction with this new idea wind power may be more usable – I put in tips/notes earlier but don’t know if it’s already been noted anyway – it seems semi appropriate to this thread I think..as it could hold a key to actually being able to use short term/irregular power sources?
http://www.monash.edu.au/news/show/graphite-water-the-future-of-energy-storage

1DandyTroll

DocWat says:
July 16, 2011 at 2:13 pm
“Don’t VAWTs have their own problems, besides being ugly?”
Yes, the more effective they are per square foot, as in not taking up much space, the less likely they are to be promoted. The two reasons for this that I see are why would government pay subsidies for highly effective and inconspicuous hardware? The second reason is why promote cheap technology that takes no place that bothers no one and that effectively lessen the need for “Big Energy” production?
In my country a singel VAWT for “home use” can generate more ‘an is need for ones need, which the horizontal versions do not, but connecting a VAWT to the grid is discourage through the cost of doing such an “evil” thing, which is supported by the greenies of course what with their seemingly need to tax people to death or what not.

Robert of Ottawa

This is a really good piece of work. It shows how we can produce energy just as inefficiently employing only 10% of the real estate previously required.

Wyguy

I hope that in the future wind turbines will bring great scrap prices!

Robert of Ottawa

Doug in Seattle,
I work for a Global Enterprise, and I do not like to see this sort of political malarky. Global Enterprises should make money by selling stuff people want, not what governments command.

Claude Harvey

One of the funniest things I ever saw occurred back in the “eggbeater” experimental days near Palm Springs, CA. DOE had sponsored (thus dooming the outcome from the beginning) construction of a very large vertical axis wind turbine. After innumerable fits and starts, they got the awful thing spinning; REALLY spinning (they must use an induction motor to get the beasts turning, even when the wind is blowing). Then a blade detached from the bottom hub and swung in a 360 degree arc about the axis, severing the support cables. The whole rig came crashing to the ground in a cloud of debris and dust as folks ran for their lives. It was a major “Aw S–t” moment I will never forget!

Gary Pearse

This counter-rotating efficiency ends when a few among them fail as they are wont to do.

Hoser

Bearings already are a weak point with HAWTs. Imagine the torque on a VAWT.
You can imagine various fixes for that problem. However, no matter what they do, O&M costs will make this a loser.

Doug in Seattle

Robert of Ottawa,
Yeah, that would be nice. I will miss incandescent light bulbs.
Doug of Carlsbad Springs

DirkH

u.k.(us) says:
July 16, 2011 at 3:45 pm
“I have never walked through a coal or nuclear power plant, to get an appreciation of our engineering prowess, and the scale of our power production facilities.”
Nukes are relatively small. If you want big, visit a coal plant.

“…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…”
What kind of manure is used at a wind farm, and how deep does it have to be?

Sorry, couldn’t resist the last joke.
Still, if they use a lot of these in a small area, would they cause vertical vortices? Counter rotation might tend to either send up mini-tornadoes, or mini-vacuums. Might raise problems with flights (any dust that blows in to the “field” will be kicked around and have its speed amplified).
Sounds like a ramped up Dyson…

Doug Badgero

Power output is limited by Betz’s law for all wind turbines. The following is a link that looks at the disadvantages of VAWT technology. The biggest issues are the amount of material required for the same size turbine and the sinusoidal nature of the developed torque at each blade.
http://www.motherearthnews.com/Renewable-Energy/2008-02-01/Wind-Power-Horizontal-and-Vertical-Axis-Wind-Turbines.aspx?page=4

hunter

Hmmm…..Is it possible to scale it up?
If it is, it could be the first wind mill power that is worth the trouble.
My bet is it will not scale well.

Bystander

@ Richard S Courtney “In other words, wind tubines do not provide any useful electricity to a grid at any time.”
That is a pretty ridiculous statement – if that were the case there would be no instances of wind power contributing energy to the grid (which it clearly does) and no instances of large scale wind deployments (which there clearly are).

Billy Liar

This is premature reporting. Figure 3 reveals that in their experimental setup, basically the wind always blew from the same direction. They’re extrapolating performance with very limited range of a critical parameter.
They should come back with a more convincing report when their wind rose shows wind from all points of the compass.
D- re-submit.

Dr. Dave

Tallbloke provided a link to some VAWTs that are certainly more aesthetically appealing than your typical tri-blade bird and bat chopper. I am interested to know the energy output per unit cost of these “pretty” VAWTs vs. typical HAWTs. I lived in Amarillo, TX for a little over 10 years and left just before the entire west Texas panhandle was blighted with twirling eyesores. Very near the legendary Cadillac Ranch on old US 66, one of the universities had a huge VATW eggbeater. I never saw the thing spinning, but apparently they recognized the potential of wind in the area and studied the VAWT design as early as the early 80s. Over the last 10 or 15 years (but mostly over the last 2 or 3) various and sundry Texas energy concerns invested over $7 Billion in HAWT whirligigs. I find it hard to believe they would have dumped all that money into HAWTs if VAWTs were actually a more more efficient and cost-effective design.
The design and associated aesthetics are actually immaterial. If the taxpayer subsidies went away tomorrow these hulking eyesores would be rendered into scrap before the end of the year (just imagine the opportunities for copper theft). Any industry or technology that cannot exist without subsidy is by definition a non-viable industry or technology and should be allowed to wither and die in the clean sunlight of the free market. When will politicians learn that you can’t subsidize new technologies into existance? Most of the western world has been taken for a ride with this ridiculous wind power scam. But a few special interests (and politicians) have made out handsomely.

Some of the comments above, which appear to me to denigrate wind power, prompt the following response. First, wind power is not the end-all for power production. It has many problems, one of which I mentioned in the post above: intermittency. Yet, as shown in the link below, that is not as big of a problem as some would claim, based on the California experience.
This link, http://www.caiso.com/green/renewrpt/20110714_DailyRenewablesWatch.pdf shows the hour-by-hour generation in California’s ISO grid area for July 14, 2011, with various renewable energy forms shown in different colors. Wind power on that day peaked at just over 2100 MW, and reduced to about 1200 MW. The peak production is more than the output of a typical twin-reactor nuclear power plant in the US. The minimum output is more than the average single-reactor nuclear power plant. The total installed MW is approximately 3,100 MW.
This link, http://caiso.com/outlook/SystemStatus.html shows the current status in California for power production. Note that this information will change over at midnight to the next day’s data. The key is the amount of spinning reserve, which is approximately 9000 to 10,000 MW above the actual demand. Thus, having a wind turbine or two reduce power,or trip off-line will make little to zero difference in the amount of spinning reserve. The operators of the state grid are required to have spinning reserve in order to meet unexpected changes in the load, such as the sudden loss of a large generating plant. Four of the largest generating plants in California are the four nuclear powered reactors, two each at San Onofre and at Diablo Canyon rated at approximately 1000 MW each. Having a few 500 kw wind turbines, or even a few 2 MW wind turbine, slowly reduce their output as the wind changes is not much of a factor.
It should be noted that the summer months are the peak wind period in California, with the winter months the lowest wind period.
It should also be noted that California has wind turbines primarily in three areas, where the wind is rated as a Category 6: Altamont Pass, Tehachapi Pass, and San Gorgonio Pass. These are very small geographic areas with excellent wind speeds. There are far greater geographic areas than these three small mountain passes, with wind of Category 5 and Category 4, primarily in the Plains states from Texas to North Dakota. The advancement in power output per acre, as discussed in Dr. Dabiri’s paper, will be of keen interest to land owners in the Plains states. Producing ten times as much power from a given area of fairly flat land, while continuing to grow crops on that land, would seem to be a fairly attractive proposition.
For those who might be interested, this link from the US Dept of Energy shows the wind speed throughout the US at 80 meters height (approximately 250 feet) and 100 meters (approximately 330 feet). Each state has an individual map. http://www.windpoweringamerica.gov/wind_maps.asp

DirkH says:
July 16, 2011 at 2:40 pm
Birds produce CO2. CO2 evil. Die Birds Die! (That’s German for “The, Birds, The”)

Nice try, but you have achieved only failure. “Birds” is not the German word for birds.

old engineer

I’m not sure why VAWTs lost out to HAWTs. The VAWT problems all sound like engineering problems that could be over come. However, as several comments have indicated, no matter what technology is used, there is still the problem of varying output depending on wind conditions (including zero output at both no wind and high wind conditions).
I have never understood why pumped storage for load leveling has never been used with wind turbines. Pumped storage has been used for over 100 years around the world for load leveling.
For those not familar with the technology, when power is produced that is not needed on the grid, the excess electricity is used to power water turbines which pump water from a lower storage area to a higher storage area. When the grid requires more power than the power production unit (coal, gas, wind, whatever) output, the water is allowed to flow back down the hill through the turbines producing electricity. Of course, there is an inefficiency, since more power is required to pump the water uphill than is obtained when the water flows back down hill. But no energy storage device is 100% efficient.
While sea level wind farms would have a problem using pumped storage, areas where an elevation difference is available would seem to be able to use this technolgy. Fpr instance, at the wind farms around Iraan (pronounced “Ira-ann”), in West Texas, the wind turbines are all on the top of mesas, which are 100 or so feet above the surronding terrain. Looks like an idea spot for pumped storage.

Dan in California

There was a row of FloWind Darrieus vertical rotors on Cameron Ridge in Tehachapi. I think they were 140 KW each. They were replaced several years ago with ~1 MW horizontal axis machines. Today, the slope between there and the town of Mojave is getting filled with new 1.5 MW turbines. They are approaching the town like monolith monsters. More than 1000 MW and growing.

Crustacean

Okay, Roger, you obviously know your stuff, but, not to put it too harshly, who the Hell cares? These things are a hideous blight on the landscape and produce nothing that can’t be produced simultaneously, far more efficiently and with far less environmental destruction, by the backup generation they can’t do without.
If you care about CO2 emissions–which I surely don’t–then you need to be looking for something that actually helps reduce them instead of something that helps the true believers pretend.
I won’t live to see the day when you can cross the United States without seeing ONE of these stupid, useless contraptions, but others will and that will be a happy time indeed.

anticlimactic

If it doesn’t need subsidies then it is an improvement. If it still needs subsidies then they are still white elephants.
I can’t help wondering that if each VAWT had a pump which fed hydraulic fluid to a single central generator then the cost should be reduced further.
If wind turbines ever do become viable as a source of energy I would think it best if all the output was channelled in to systems like Electric Mountain in the UK. In this hydroelectric system water is pumped from a lower lake to a higher lake overnight using spare energy [probably from nuclear which needs to run at 100% continuously]. The stored power is then released at times of peak demand, such as millions of kettles being turned on at the end of a popular TV program. It can go from zero to 2 gigawatts in 12 seconds.
If similar systems were used for wind power then at least the unevenness could be smoothed out and the power released in a controlled way. This type of system could probably only store a days supply so does not overcome the basic weakness of wind which is variability across the year.

JDN

@Roger Sowell July 16, 2011 at 6:23 pm
Nice maps & power site. We all know that there is a tendency to exaggerate performance numbers for public consumption… until you get caught. Has anyone looked into whether these numbers in any way match reality?
By my back of the envelope calculations, CA has >3GW of installed wind power and about 1.6 GW average production over the last day (so far). That’s about 50% of rated power; an excellent figure. However, you point out that this is a good time of year for wind energy in CA. How does winter look for % of rated capacity? Is there any independent auditing? You remember the Muir trust study that found reliability problems with UK wind power, right? Is there anything comparable where an independent group has looked into the reliability of CA wind power? It might be that CA has the most reliable wind power in the world, in which case, nobody can fault it. But the green cheerleading is so overwhelming in CA that I doubt the objectivity of the site reporting the power output.

anticlimactic

Interesting article on JoNova : Using wind to provide 5% of demand saves 4% of CO2 emmissions, If wind provides 20% of demand it only saves 2%!
http://joannenova.com.au/2011/07/lessons-in-wasting-money-use-more-wind-and-solar-and-emit-just-as-much-co2/#more-15865

u.k.(us)

Jeff Alberts says:
July 16, 2011 at 6:40 pm
DirkH says:
July 16, 2011 at 2:40 pm
Birds produce CO2. CO2 evil. Die Birds Die! (That’s German for “The, Birds, The”)
Nice try, but you have achieved only failure. “Birds” is not the German word for birds.
=====
Jeff Alberts, tell me, just what have you achieved with this pitiful comment.

pofarmer

“Producing ten times as much power from a given area of fairly flat land, while continuing to grow crops on that land, would seem to be a fairly attractive proposition.”
If the picture with the article is a true indication, that area isn’t going to farmed. Modern implements are getting larger, if the spacing becomes too close, and impacts profitability, those acres will be abandoned.

Claude Harvey

Re: JDN says:
July 16, 2011 at 7:11 pm
By my back of the envelope calculations, CA has >3GW of installed wind power and about 1.6 GW average production over the last day (so far). That’s about 50% of rated power; an excellent figure.
California wind farms do not experience anything close to a 50% capacity factor on an annual basis according to industry reports. The highest wind farm capacity factor reported by the industry anywhere in the word is a single farm located in the howling sands of North Africa (Morocco Amogdoul) with a capacity factor of 38.1%. The U.S.average is 28.8% and the world average last year was 19.6%. The “dog” record went to France with 14.4% with Poland threatening at 14.6%.
Run the numbers with any of those capacity factors and you will see that unsubsidized wind power is an economic dog with nowhere to really improve due to an inherent energy-density limitation that precludes sufficient economy of scale solve the problem (too much physical material for too little power output).

Stas Peterson

Lots of comments poated here that are flat out wrong. California generated less than 70% of the power deamands of California. It must meet the missing 30% meets the balance by importing every watt available from neighboring states at a high premium. It even imports power from unreliable third world Mexico.
Ttwo of the four nuclear plants in iawere closed down thanks to green loon protests, and converted to a solar plant producing less than 1/2 of 1% of the energy when it operated as a nuclear plant. Thus making it the most expensive power from a single capital investment anywhere.
California green loon dominated PUCs have closed its coal power stations, and will not license any future coal power stations.
Instead it get its very dirty, power by importing it form ancient, obsolescent, and polluting power plants in neighboring states, that were California demand gone, most would be closed and scrapped eliminating their unchecked pollution emissions.
I have frequently traveled through the California “wind valley” windmils near Palm Desert on I-10. Most times only one or two of hundreds are operating.
Britain’s public utility which operates many windmills, reports that the use factor is about 9% whereas typical commercial operation of other power stationss in the high 90% range. They cannot be used if either there is no wind, but most don’t know that they can’t operate if the wind is too strong or they will wipe bearings and lose their windfoils, (propellers) to fatigue stresses.
The life until extensive maintenance is required, is under 10 years, and the refurbishment costs more, than the capital cost of a new windmill. Meanwhile windmills are “designed and financed ” as though they can operate for 30 years. Most windmills are set up as single companies, that are bankrupted as soon as all the tax benefits have been milked, and exhausted.

@JDN, re wind capacity factors.
The link below provides an exhaustive study of wind power, capacity factors, and much else over a multi-year period in California. Capacity factors change from quarter to quarter, and year to year, and from location to location. From just a quick glance at the charts, the highest capacity factor was 72 percent at San Gorgonio in Q2 of 1998, while the lowest was 3 percent at Solano in Q1 of 1998 and again in 1999. Statewide average was about 22 percent from 1996 through 2002. see http://www.energy.ca.gov/2005publications/CEC-500-2005-185/CEC-500-2005-185.PDF and Table 2.1 and following.
Some periods have much, much higher capacity factors (see Figures 2.7 and 2.8) where values of 70 and 80 percent are shown for brief periods of a few hours.
A quick check of the numbers from California Energy Commission website for calendar year 2010 shows roughly 6200 GWhrs produced by wind in-state, and if 3100 MW was installed (a roughly accurate number) then the annual average capacity factor was about 23 percent.
California achieves this (and has done so for more than a decade) with only a few, very small sites. Yes, the capital costs were largely subsidized. It probably looked like a good idea when natural gas prices were soaring, with dwindling supplies being predicted. These days, with technology improvements in natural gas production and a glut of natural gas, wholesale gas prices are around $4 per million Btu. Even so, wind power now is considered cost-competitive in California. This California Energy Commission document, Slide 12, shows onshore wind power’s levelized cost at approximately 8 cents per kWh.
http://www.energy.ca.gov/2009_energypolicy/documents/2009-08-25_workshop/presentations/04_Al_Alvarado_CEC.PDF

Stas Peterson

Lots of comments posted here that are flat out wrong. California generated less than 70% of the power deamands of California. It must meet the missing 30% balance by importing every watt available from neighboring states at a high premium. It even imports power from unreliable third world Mexico.
Two of the four nuclear plants in California were closed down thanks to green loon protests, and converted to a “renewables” plant producing less than 1/2 of 1% of the energy as when it operated as a nuclear plant. Thus making it the most expensive power from a single capital investment anywhere.
California green loon dominated PUCs, have closed its coal power stations, and will not license any future coal power stations.
Instead it get its very dirty, power by importing it form ancient, obsolescent, and polluting power plants in neighboring states, that were California demand gone, most would be closed and scrapped eliminating their unchecked pollution emissions.
I have frequently traveled through the California “wind valley” windmils near Palm Desert on I-10. Most times only one or two of hundreds are operating.
Britain’s public utility which operates many windmills, reports that the use factor for windmills is about 9% whereas typical commercial operation of other power stationss in the high 90% range. They cannot be used if either there is no wind, but most don’t know, that they can’t operate if the wind is too strong or they will wipe bearings and lose their windfoils, (propellers) to fatigue stresses.
Britain reports life until extensive maintenance is required, is under 10 years, and the refurbishment costs more, than the capital cost of a new windmill. Meanwhile windmills are “designed and financed ” as though they can operate for 30 years in the US. Most windmills are set up as single unit generating companies that are bankrupted as soon as all the tax benefits have been milked, and exhausted. S-C-A-M describes the situation.

RACookPE1978

old engineer says:
July 16, 2011 at 6:41 pm

I have never understood why pumped storage for load leveling has never been used with wind turbines. Pumped storage has been used for over 100 years around the world for load leveling.
For those not familar with the technology, when power is produced that is not needed on the grid, the excess electricity is used to power water turbines which pump water from a lower storage area to a higher storage area. When the grid requires more power than the power production unit (coal, gas, wind, whatever) output, the water is allowed to flow back down the hill through the turbines producing electricity. Of course, there is an inefficiency, since more power is required to pump the water uphill than is obtained when the water flows back down hill. But no energy storage device is 100% efficient.

Where are you going to get the original water and tons of make-up water per day for evaporation for your imaged top-of-the-mesa lake? Where are you going to build the lake? Or are you going to try to build an artificial dam completely around the top of the mesa?
Enviro’s have opposed EVERY pumped storage system attempted to date. Only a very few – in any case – are viable in any location: downstate NY, TN near Chattanooga by the TVA, etc. Even the NY Indians viciously opposed the very reasonable flow storage pond uphill from the Niagara power plants that was for condemning only about 1500 acres of 10,000 needed with no pumping and only a small extra dam at all! (And that was back in the mid-50’s – “now” how much enviro opposition would you expect?)
You require essentially two “lakes” (or a “perfect river” with constant water level) immediately next to each, the second “lake” about 200 feet above the first. (First problem – find the elevation difference, then find the “lake” geometry and geology and topography (land shape) in the same area as the wind source. Hint: NO effective wind power is available in the entire SouthEast due to the prevailing calm winds of the Bermuda high over 1/4 the land area of the continental US.