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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davidgmills:
I wonder what you would consider to be a mature technology.
At July 18, 2011 at 4:55 pm you say;
“Is it just me or does anyone else see that those who oppose wind power act as if no technological improvement in wind power will ever take place; yet whatever their power of choice is, it always seems to be an infant technology that given enough time will be cured of all of its technological deficiencies?”
So, according to you, wind power is “an infant technology”.
Vertical-axis windmills to mill corn were first developed by the Persians around 1500 BC, and they were still in use in the 1970’s in the Zahedan region.
The horizontal-axis wind turbine was invented in Egypt and Greece around 300 BC
Around 1200 AD, the crusaders built and developed the post-mill for milling grain.
This post-mill technology was first adopted for electricity generation in Denmark in the late 1800’s. The technology soon spread to the U.S. where it was used to pump water and to irrigate crops across the Great Plains.
During World War I, some American farmers rigged wind turbines to each generate 1 kW of DC current.
If you consider that to be an “infant technology” then what do you consider the steam engine to be, foetal technology?
Wind power was abandoned when the greater energy intensity available from fossil fuels became available by use of the steam engine.
Wind energy powered most of the world’s shipping for thousands of years. This is the most efficient use of wind power because all the wind power collected by the sails is used to push the ship without any mechanical losses. Sails had continuous developments for thousands of years. But primitive steam engines rapidly replaced sails for pushing ships.
I again point out that
If wind power were sensible then oil tankers would be sailing ships.
Richard
@ur momisugly Richard S Courtney says “If wind power were sensible then oil tankers would be sailing ships.”
That doesn’t make a lick of sense. We’re talking about power generation for the grid not transportation. No one here is proposing that wind be the sole source of power generation.
@ur momisugly Richard S Courtney says “I wonder what you would consider to be a mature technology.”
Another straw man Richard – large scale wind generation of electricity is a new technology. Grinding grain around 1200 AD isn’t the same as utilizing wind power for large scale generation of electricity back to the modern grid.
As usual – your reliance on straw man arguments simply confirms you have no interest in a factual discussion. To that point – are you willing to acknowledge your straw man arguments in your “paper”?
@ur momisugly Richard Courtney says “But both are as spurious as your original arguments. . ”
You mean like ignoring fundamental methodology and factual errors in your paper Richard?
@ur momisugly Ralph says: “Wind power can never be economically integrated into a power grid.”
That is a ridiculous statement. We all know full well that wind power is traded on the electricity markets in Europe, if the delivered cost was non-economic compared to the full burdened cost of conventional fuel this would not be happening.
And yes, fully burden costs matter. Coal has huge externalities. For example;
“Upstream externalities for coal include mining and surface
reclamation. Oil and natural gas use have issues
associated with drilling, pipelines, and spills.50 Hydroelectric
power is associated with flooding, erosion, and
loss of aquatic life in addition to possible curtailment of
aesthetics and a loss of habitat for certain species.
Downstream externalities are associated with landfills/
ash disposal, climate change (or global warming
potential), acid rain, transmission lines (electromagnetic
fields), and siting. Nuclear power generation has the
potential for serious accidents, besides problems with
mining, surface reclamation, and waste disposal.
Recently, various studies have taken into account externalities
(i.e., damages and benefits) associated with each
fuel cycle in power generation. A fuel cycle is the series
of physical and chemical processes and activities required
to generate electricity from a specific fuel or
resource, including primary resource extraction and
preparation, transport and storage of resources and
materials, processing and conversion, and disposal….
Environmental costs from the front end of the fuel cycle
(mining, milling, drilling, beneficiation, fuel processing,
equipment manufacturing, fuel transportation to site,
etc.) do not directly devolve on the electric utilities,
however. Therefore, impacts (or externalities as stated
above) that are a part of the complete fuel-cycle
approach are not normally taken into account when
considering power generation per se.”
http://www.eia.gov/cneaf/electricity/external/external.pdf
Richard S Courtney
Actually, Richard, I do not agree with all of your points. You were the person suggesting coal fired power as backup for renewables (despite coal’s inability to respond to power fluctuations), and two of the major reasons for discussing windmills in the first place are (1) reducing GHG’s and (2) dealing with ongoing fossil fuel depletion. That’s not changing the subject, but simply pointing out some of the other reasons why this particular research on high density wind power (and other renewables) is important.
Your argument that wind power does not reduce, but indeed increases CO2 emissions is simply false, a result of assuming coal power plants (that cannot be throttled efficiently, and which have only 80-90% availability themselves) are the only backup option. Tied to that is your lack of accounting for dispersed wind generation, which greatly decreases the need for backups. Archer 2007 (http://www.stanford.edu/group/efmh/winds/aj07_jamc.pdf) shows, for example, that with 18-20 sites spread across the US Midwest an average of 33% yearly wind power can be used as reliable baseload power. The other 2/3 is more intermittent, but could be used for generating CO2 neutral transportation fuels, fed into storage facilities to raise the baseline levels, etc.
You’ve emphasized some of the very worst options possible in arguing that wind power is unworkable. I cannot regard that as a balanced viewpoint.
Bystander and KR:
I will reply to your responses to my posts if you address the points I made in those posts. Until then, people can compare my points to your strawmen and draw their own conclusions.
Richard
The Wind Power Paradox: BENTEK Analysis Shows CO2 Savings Through Wind Power Are Either So Minimal As To Be Irrelevant or Too Expensive To Be Practical
http://www.businesswire.com/news/home/20110719007251/en/Wind-Power-Paradox-BENTEK-Analysis-Shows-CO2
[snip]
EVERGREEN, Colo.–(BUSINESS WIRE)–For years the wind energy industry and numerous state and federal politicians have claimed that increasing the use of wind power to produce electricity will result in huge reductions in CO2 and other emissions. These claims rest on the results of dispatch models that predict not only emissions, but also fuel costs and generation levels for individual utilities and utility grids. A new Market Alert from BENTEK Energy, The Wind Power Paradox, presents findings that show these claims to be significantly overstated and that actual CO2 reductions are either so small as to be insignificant or too expensive to be practical.
Kev-in-Uk,
Thank you for working on this with me.
“In other words, a bit like the private Toll bridges where they collect a ‘toll’ to recover the investment outlay and running costs, but then continue to collect tolls even after many years (usually increasing them instead of reducing them to cover basic running costs after the capital cost have been met!).”
You presume there is no competition. I suppose there usually isn’t in utilities. This does happen with public-controlled infra, like toll bridges, but not enough to interfere with the outcome of the plan. In reality the abuse in these situations does not rise above a certain threshold that would cause enough of the effected citizenry to become active in their government and fix it. You could argue that that could be improved somewhat if money wasn’t able to influence government more than your vote, and you’d be right, and that’s pretty much my second favorite issue next to energy transition and better technology.
“The free market would likely find a way to take advantage, I am sure – just like it has with the subsidised ‘green’ industry!”
The problem is because of the *lack* of a free, competitive market. It is because the road and utility market is naturally monopolistic and thus controlled by the state. Any time government contracts business there is a possibility of abuse, but the answer is a vocal citizenry. (I would love it if my neighbors were more vocal and demanded a Renewable Energy Portfolio from my electric utility, and higher payback to households who generate their own power (PV). I actually advocate for that to my representatives locally…and federally, for a federal REP! I would love it if the people on this blog would do the same.) Further, the problems are limited in their gratuitousness and longevity. It doesn’t hurt the long term outcome of the plan. If your neighbors, fellow constituents, are stupid, educate them.
“I am a self employed engineer, so not really a businessman! but if I was gonna make and sell something, I’d look at the current market, make whatever the ‘product’ I chose at reduced cost (if possible) and then sell it the most I could get for it but usually just under my competitors price! I am not satisfying shareholders – but big corps are, and need to look at the profit margin ALL the time. I cannot see in your suggestion, that the free market could provide a fair solution for consumers!”
Yes, the free market, absent competition and many players, always fails. The only thing worse than a public [near-]monopoly is a private [near-]monopoly. (The right needs to quit letting mergers happen! They need to quit arguing against limited market-ownership rules! They are fooled by duplicitous arguments by liars posing as defenders of the free-market faith.) The solution for most markets is more players, and the solution for natural-monopolies is more active voters. The abuses of your power utility are limited by when they piss off enough of your neighbors, you can march up to them and force them to drop their obscene ROI to something more reasonable. They don’t end up siphoning any more money off of the economy in the long run than they do already with fossil fuels!
“Nuclear promised cheap electricity – which I guess it delivered for a while, but then H&S and Enviro regulations became more stringent and costs rose (especially decommisoning – nobody foresaw decom costs to be so high I don’t think)….and then of course, add in the NIMBY’s and you have got yourself a perfectly good method of electrity production that is ‘not wanted’, and yet a few million wind gensets are ok?….or flooding vast areas for hydro is ok?, etc, etc… At some stage, practicalities need to come into the equation.”
So, what your saying, is everything else being equal, a fossil fee and tax cut isn’t? I’ve lost your argument.