Wind Turbine power output is increased ten-fold by careful spacing, and direction of rotation, when compared to existing best practices.
Click 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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Never mind, with the smart meters being installed we’ll soon all be able to choose which power we use and which tariff we pay.
Everyone who signs up for the “green” tariff will be able to pay more for the more expensive generation costs and will also be able to be disconnected when the wind stops blowing. The rest of us will be able to have power all the time at a cheaper rate. There will be no more need for expensive subsidies by taxpayers as the vast majority (concensus) will be on the higher rate – won’t they?
sarc/ off
I was in Germany at the beginning of last December, just when the “Global Warming” was starting to fall (and very pretty it was, too). The area (Harz) then settled down to enjoy a period of high pressure. Snow remained on the branches of the trees and smoke went straight up. Yet the White Elephants went on turning. Odd, that.
Re: pumped storage. Denmark has large numbers of white elephants and found that they so banjaxed the grid that they now tend to export the power (when the wind blows) to Norway to be used to pump water into high tarns. They then buy electricity back from Norway when the wind isn’t blowing. Canny lads, those Nogs – not for nothing are they known in certain circles as “White Arabs”.
Pete in Cumbria:
For some idea of Chris Huhne’s criteria for beauty, see . !
Damn! How do I put a URL in here?
http://www.anorak.co.uk/251374/politicians/chris-huhnes-taxi-shame-with-carina-trimingham-pictures.html
[Just like that. ~dbs, mod.]
@cwj on July 16, 2011 at 10:22 pm
“Am wondering how they intend to filter out the unacceptable electricity.” – referring to coal-produced electricity imported by California,
In this case it won’t be very difficult, because the coal-powered plants are in Utah, It will require simply opening (disconnecting) the switches on high-power transmission lines from Utah into California. There is approximately 10 years until that happens, which allows the California power companies time to build replacement capacity. Much of that power is imported into Los Angeles, by the city-owned utility Los Angeles Department of Water and Power (DWP). DWP is frantically designing and advancing projects to replace the coal-based power. At least a part of that new supply will be from renewable sources, wind, solar, and waste-to-energy.
@Kev-in-Uk from July 16, 2011 at 11:26 pm
“as a slight aside – I note that the graph on that CSIRO link shows a difference of demand to Available resources of something around 10000MW – I am wondering what that is made up…”
The spinning reserve in California is typically natural-gas fired load-following plants such as a steam plant (Rankine cycle) or a combined cycle gas turbine (CCGT) plant. As others have noted, California has no coal-fired plants in the state. The four nuclear reactors operate at base load. The wind and solar are not dependable so are not part of the spinning reserve. Hydroelectric can be increased very quickly.
@ur momisugly Nylo from July 16, 2011 at 11:56 pm
“It doesn’t really matter that the electricity production per square meter increases ten fold, if you have to put 20 times more windmills. What matters in the end is how much more money you have to spend to get that 10-fold increase in production, or how much energy produces each individual windmill, whose construction and maintenance cost is much more important than that of the land it stands on. That’s what efficiency is all about. Money vs energy, not land vs energy. Less land is only interesting if it means less money spent per kWH obtained.”
Actually, it matters a great deal that power production per square meter increases 10-fold. Normally, increases in power production, or efficiency, are made in small increments. One usually reads of a wind-turbine improvement of 2 or 3 percent over the previous effort. Or, one reads of the average capacity factor increasing from 20 percent to 23 percent by better design, less downtime, etc. This research, though, provides a HUGE increase, by a factor of 10. That caught my attention because it is a very rare thing, and prompted this article on WUWT.
For a state like California, with its legal mandate to increase renewable energy production to 33 percent of all power sold, but where good wind is available only in very small areas, it could result in replacing the HAWTs with many more VAWTs. For future projects in other states or countries, it will likely cause project planners to re-evaluate their plans. For manufacturers of VAWTs, this could easily improve their commercial prospects. Conversely, manufacturers of HAWTs will likely see their commercial prospects dim.
@Alexander Feht from July 17, 2011 at 1:16 am
Re not seeing wind-turbines turning,…
“Now, what should I believe: the socialist fanfare statistics promulgated here by Roger Sowell, or something that I see with my own eyes?”
Mr. Feht, thanks for the laugh this morning! I just try to present the facts, with some editorial input from me. The facts are very plain: wind-turbines exist in many places. They don’t operate at 100 percent capacity due to the variation in wind. This is not news. Some places are better than others for placing wind-turbines. Wind-energy assessments were conducted, and the results are freely available for all to see. I gave a reference for that above.
It is tempting to believe one’s own eyes, and I do that myself. However, each of us cannot be in all places at all times. Just in California, with the 3 or perhaps 4 primary locations of wind-farms, there are thousands of wind-turbines installed. I have seen hundreds of them spinning full-bore in San Gorgonio Pass, many, many times. But, my personal eye-witness experience means nothing because no one can witness all the turbines, all the time. We must therefore rely on credible reports from others. In California, wind-turbine farms are paid by the large utilities for the power they produce. There must be credible evidence of power production, else the utility does not pay them. The utilities are required, by law, to report the wind production to the state.
If you want to characterize these facts as “socialist fanfare statistics,” you have the right to do so. Again, thanks for the laugh!
For the record, I’m not a particularly big fan of subsidies to wind-turbine farms, but I understand the reasons why those subsidies are there. Lawmakers with little understanding of energy were convinced that fossil fuels would soon run out, especially natural gas, and that wind-power was inexhaustible. They believed that natural gas price would soar, and electricity rates would also skyrocket. They were also convinced that the costs of wind power would decline year after year, and it has done so. They were also convinced that the problems of variable wind would be solved by some bright engineers. Therefore, they felt that subsidizing wind power was the right thing to do.
As it turns out, they were wrong on almost every point. The costs of wind power has declined over the years, and that’s about the only thing they got right. The costs declined due to more efficient blade designs, and economy of scale with bigger turbines. We are not running out of fossil fuel, indeed there is a glut of natural gas. Oil is not a factor in power production in the USA (in some less developed countries, it is, but not in the West.) Natural gas prices are at approximately $4 per million Btu, and will stay there for many decades. Electricity rates are not skyrocketing due to natural gas price. Variable wind continues to be a problem. It is quite possible to store energy from wind-turbines, but it is not at all economic, at least not at this time.
Roger Sowell says:
July 17, 2011 at 7:28 am
Thanks for the explanation. But I also noted that the available resources graph seems to follow the ‘demand’ graph though – which seems a little odd to my way of thinking. I mean, is it really necessary to have about 35 to 40% above and beyond current use on ‘standby’ or ‘available’ as spinning reserve – it seems a lot to my ignorant eye!
Roger appreciate your comments. I have always wondered if vertical wind turbines would make good compressors for freon and thus be able to be used for home application. I have read that somewhere in the near 60% of home electrical usage is for heating and cooling. It would seem like a good vertical turbine which can operate at very low and very high wind speeds would be perfectly suited for compressing freon and making home heating and cooling much more affordable. Compression of freon or similar gas would seem to be a good means of solving the intermittent power problems created by wind variation and you would not have the losses of turning wind power into electrical power. Any thoughts or know of any such applications?
Roger appreciate your comments. I have always wondered if vertical wind turbines would make good compressors for freon and thus be able to be used for home application. I have read that somewhere near 60% of home electrical usage is for heating and cooling. It would seem like a good vertical turbine which can operate at very low and very high wind speeds would be perfectly suited for compressing freon and making home heating and cooling much more affordable. Compression of freon or similar gas would seem to be a good means of solving the intermittent power problems created by wind variation and you would not have the losses of turning wind power into electrical power. Any thoughts or know of any such applications?
“Copse effect” will still frustrate high-density deployment.
If you’re outdoors on a windy day, walk towards a small forest and slowly past the rows of trees from the perimeter. It’s not just the screening of the outer trees that results in much less wind in the interior; it’s Le Chatellier’s Principle at work. The wind will divert around/over any sufficiently-large obstacle as it’ll lose less energy that way.
You can even observe this with the rain in Spain, which falls mainly in the plain. Not on the small hills on the plain because the wind blowing the rainclouds “splits” around the hills; even if they’re only 100 metres above the plain.
And it doesn’t just happen in Spain. On a recent trip to Germany, after having coincidentally reminded an old university Professor of the principle the evening before, we had a full-scale demonstration when visiting a monastry and castle ruin atop a hill. Although leading edge of the long hill got some rain, there wasn’t a drop at the trailing end while rain wall falling on either side. There was a clear “rip” in the dark cloud cover above the hill that hadn’t been there in the cloud front as it had approached.
The real problem is not the intermittent nature as such. The problem is that wind power happens exactly when you don’t need it. An intermittent source that arrives in both supercold and superhot weather would be helpful. Wind is highest at moderate temperatures (spring, fall, warm fronts in winter, cold fronts in summer) when you don’t need the extra.
Increasing the output only makes the problem worse! More wasted power when you don’t need any extra.
But if we take too much energy out of the wind, we will surely make it back more (its direction will go more anticlockwise in the N Hemisphere), and the wind with be directed towards the center of the low, resulting in much tighter low pressure systems. Will this not make smaller but more intense hurricane-style low pressures, that will do more damage to property?
.
@davidgmills on July 17, 2011 at 9:02 am
” Compression of freon or similar gas would seem to be a good means of solving the intermittent power problems created by wind variation and you would not have the losses of turning wind power into electrical power. Any thoughts or know of any such applications?”
The energy storage technology you describe is CAES, for Compressed Air Energy Storage. Typically, these systems use wind power to compress air into underground caverns. When electric demand is high, the compressed air is released and fed into gas turbines for power generation. There are some energy losses, as the compressors have an inefficiency, plus the air cools a bit in the storage. CAES is very limited due to a lack of suitable underground storage caverns located near to wind farms. A similar system could be used as you describe, with freon compressed by a VAWT then stored in high-pressure containers. However, there are energy losses with this system. The engineering is not a problem, but the cost and therefore economic payback of such a system is likely very poor.
One of the best ways of using a VAWT to help cool a home is to install roof ridge-line VAWTs as vents (turbine roof vents). Some of these include a small fan to pull hot air out of the house’s attic space.
I wrote an article about two years ago on Energy Storage, at http://sowellslawblog.blogspot.com/2009/05/energy-storage-key-to-renewables.html
@Stas Peterson
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.
Do you have any evidence that supports the bold statement? This would be good info to expose…
In summary :
Wind turbines produce power at huge cost compared to any other method [apart from solar]
At best they reduce CO2 by 4%, reducing to zero the more they are used.
The power is intermittant and so may often be unusable.
They require 100% fossil fuel backup systems, or blackouts.
Over a certain level their use can destabilise the whole grid leading to complete failure.
They require a very expensive infrastructure to feed power to the grid.
They are very mechanical and subject to stresses which can easily damage them.
They are blots on the landscape, although the main issue is sound.
They use rare earth magnets, the mining of which creates extremely toxic waste.
They kill birds and bats in quantity.
Wind is forecast to drop noticeably for the next 30 to 40 years [In the UK anyway]
In short, they would seem to offer little or no environmental benefits so what are they good for?
THEY ARE GOOD FOR PRODUCING WEALTH! NOTHING ELSE MATTERS!
In the UK a large 2 Megawatt turbine can produce profits of a million dollars a year. The Prime Minister’s father-in-law makes money from wind turbines. Is Cameron being ‘green’ or simply wanting to inherit millions paid for by unimportant people as they try to heat their hovels. Energy prices in the UK may double or quadruple in the next 10 to 20 years, mainly due to the cost of wind turbines. Energy utilities in the UK make a fixed profit on turnover, so expensive power increases their profits.
If you are lucky enough to own land which is marginally suitable for a wind turbine then you can retire in extreme comfort.
HOW MANY WIND TURBINES WOULD BE CONSTRUCTED IF THEY WERE SUBSIDISED ‘AT COST’, WITH NO PROFITS, JUST FOR THE PUBLIC GOOD? MY GUESS WOULD BE : CLOSE TO ZERO!
http://www.thegwpf.org/opinion-pros-a-cons/3431-terence-blacker-get-rich-quick-by-being-green.html
http://climateresearchnews.com/2010/03/tory-leaders-father-in-law-rakes-in-3-5m-from-taxpayer-to-fund-wind-turbines/
Errm… with my previous post ‘2 gigawatt turbine’ should be ‘2 megawatt turbine’. I am not sure if a ten mile high turbine would be capable of using wind with any kind of efficiency!
@ur momisugly Richard – no, it is still a ridiculous statement. Citing your own paper doesn’t make it a valid source.
You say “No useful electricity”.
The Danish Energy Association says “In 2008 59 % of the electricity generation in Denmark
was produced by the central generation plants and 20 % by wind turbines.”
http://www.danishenergyassociation.com/Statistics.aspx
I saw this research a while back – apparently some of the initial work came out of looking at schools of fish, and how they take advantage of wake interactions to conserve energy while the school moves. Very interesting.
Windspire has some pretty cool looking designs:
http://windspireenergy.com/
Windspire has some pretty cool designs:
http://windspireenergy.com/
Crustacean – “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.”
Funny – I feel that way about strip mines, which litter the area.
There’s a spot just east of Somerset, Pennsylvania, that I drive through regularly on the PA Turnpike. South of the road are a half-dozen 1.4MW windmills lining the ridge. North of the road, right across, is a huge strip-mine, a scar on the landscape, which even after it’s empty of coal and refilled will be leaching crud into the water table for a century or so.
Personal opinion, but I prefer the windmills…
>>Bystander says: July 17, 2011 at 12:01 pm
>>The Danish Energy Association says “In 2008 59 % of the
>>electricity generation in Denmark was produced by the central
>>generation plants and 20 % by wind turbines.”
But while the wind was generating 20%, just how many thermal plants were still burning and turning, while waiting for the wind to drop? Do the Danish even bother to inform us of such information? And what was the cost of operating those useless power plants on spinning standby, both in terms of money and CO2 output?
.
As we are on the topic – I have just come across this article about the financial effect of wind turbines killing bats in Pennsylvania :
http://www.post-gazette.com/pg/11198/1160977-28.stm
‘In all of Pennsylvania, bats saved farmers $277.9 million in estimated avoided costs.’
The article points out that the insects not eaten by the dead bats means more pesticide needs to be used, or crops lost. It seems like a well written and informative article and is worth a read.
So, as Roger Sowell admits, whirligigs make absolutely no business sense, environmentalists lied to the duped politicians and continue to rob taxpayers, while traditionally produced electricity is much cheaper. And we have gas and coal reserves hat would lat ’til Kingdom come (not to mention nuclear power, which is the way of the future, no matter what your preferences are).
Why praise this shameless waste? Why choke the economy? Why enrich the mountebanks?