Science Current Events | Science News | Brightsurf.com
 

Wind-turbine placement produces tenfold power increase, Caltech researchers say

July 13, 2011
PASADENA, Calif.-The power output of wind farms can be increased by an order of magnitude-at least tenfold-simply by optimizing the placement of turbines on a given plot of land, say researchers at the California Institute of Technology (Caltech) who have been conducting a unique field study at an experimental two-acre wind farm in northern Los Angeles County.

A paper describing the findings-the results of field tests conducted by John Dabiri, Caltech professor of aeronautics and bioengineering, and colleagues during the summer of 2010-appears in the July issue of the Journal of Renewable and Sustainable Energy.

Dabiri's experimental farm, known as the Field Laboratory for Optimized Wind Energy (FLOWE), houses 24 10-meter-tall, 1.2-meter-wide vertical-axis wind turbines (VAWTs)-turbines that have vertical rotors and look like eggbeaters sticking out of the ground. Half a dozen turbines were used in the 2010 field tests.

Despite improvements in the design of wind turbines that have increased their efficiency, wind farms are rather inefficient, Dabiri notes. Modern farms generally employ horizontal-axis wind turbines (HAWTs)-the standard propeller-like monoliths that you might see slowly turning, all in the same direction, in the hills of Tehachapi Pass, north of Los Angeles.

In such farms, the individual turbines have to be spaced far apart-not just far enough that their giant blades don't touch. With this type of design, the wake generated by one turbine can interfere aerodynamically with neighboring turbines, with the result that "much of the wind energy that enters a wind farm is never tapped," says Dabiri. He compares modern farms to "sloppy eaters," wasting not just real estate (and thus lowering the power output of a given plot of land) but much of the energy resources they have available to them.

Designers compensate for the energy loss by making bigger blades and taller towers, to suck up more of the available wind and at heights where gusts are more powerful. "But this brings other challenges," Dabiri says, such as higher costs, more complex engineering problems, a larger environmental impact. Bigger, taller turbines, after all, mean more noise, more danger to birds and bats, and-for those who don't find the spinning spires visually appealing-an even larger eyesore.

The solution, says Dabiri, is to focus instead on the design of the wind farm itself, to maximize its energy-collecting efficiency at heights closer to the ground. While winds blow far less energetically at, say, 30 feet off the ground than at 100 feet, "the global wind power available 30 feet off the ground is greater than the world's electricity usage, several times over," he says. That means that enough energy can be obtained with smaller, cheaper, less environmentally intrusive turbines-as long as they're the right turbines, arranged in the right way.

VAWTs are ideal, Dabiri says, because they can be positioned very close to one another. This lets them capture nearly all of the energy of the blowing wind and even wind energy above the farm. Having every turbine turn in the opposite direction of its neighbors, the researchers found, also increases their efficiency, perhaps because the opposing spins decrease the drag on each turbine, allowing it to spin faster (Dabiri got the idea for using this type of constructive interference from his studies of schooling fish).

In the summer 2010 field tests, Dabiri and his colleagues measured the rotational speed and power generated by each of the six turbines when placed in a number of different configurations. One turbine was kept in a fixed position for every configuration; the others were on portable footings that allowed them to be shifted around.

The tests showed that an arrangement in which all of the turbines in an array were spaced four turbine diameters apart (roughly 5 meters, or approximately 16 feet) completely eliminated the aerodynamic interference between neighboring turbines. By comparison, removing the aerodynamic interference between propeller-style wind turbines would require spacing them about 20 diameters apart, which means a distance of more than one mile between the largest wind turbines now in use.

The six VAWTs generated from 21 to 47 watts of power per square meter of land area; a comparably sized HAWT farm generates just 2 to 3 watts per square meter.

"Dabiri's bioinspired engineering research is challenging the status quo in wind-energy technology," says Ares Rosakis, chair of Caltech's Division of Engineering and Applied Science and the Theodore von Kármán Professor of Aeronautics and professor of mechanical engineering. "This exemplifies how Caltech engineers' innovative approaches are tackling our society's greatest problems."

"We're on the right track, but this is by no means 'mission accomplished,'" Dabiri says. "The next steps are to scale up the field demonstration and to improve upon the off-the-shelf wind-turbine designs used for the pilot study." Still, he says, "I think these results are a compelling call for further research on alternatives to the wind-energy status quo."

This summer, Dabiri and colleagues are studying a larger array of 18 VAWTs to follow up last year's field study. Video and images of the field site can be found at http://dabiri.caltech.edu/research/wind-energy.html

California Institute of Technology


Related Wind Turbines Current Events and Wind Turbines News Articles


Offshore wind turbine construction could be putting seals' hearing at risk
Noise from pile driving during offshore wind turbine construction could be damaging the hearing of harbour seals around the UK, according to ecologists who attached GPS data loggers to 24 harbor seals while offshore wind turbines were being installed in 2012.

Shifting winds: An early warning for reduced energy
The Rocky Mountains certainly aren't known for their mild winters. But in contrast to the upper Midwest, which seems to exist in a perpetually frozen state from November through March, the plains just east of the Rockies do get an occasional reprieve from the bitter cold: the Chinook winds.

Vulnerable grassland birds abandon mating sites near wind turbines
Shifting to renewable energy sources has been widely touted as one of the best ways to fight climate change, but even renewable energy can have a downside, as in the case of wind turbines' effects on bird populations.

Ames Laboratory scientists create cheaper magnetic material for cars, wind turbines
Karl A. Gschneidner and fellow scientists at the U.S. Department of Energy's Ames Laboratory have created a new magnetic alloy that is an alternative to traditional rare-earth permanent magnets.

'Holey' graphene for energy storage
Engineers at the University of California, San Diego have discovered a method to increase the amount of electric charge that can be stored in graphene, a two-dimensional form of carbon.

Patents forecast technological change
How fast is online learning evolving? Are wind turbines a promising investment? And how long before a cheap hoverboard makes it to market?

Lights tuned to birds' eyes may help reduce bird-aircraft collisions
Collisions with birds are one of the most common hazards to aircraft, causing $700 million in damage annually in the U.S. A study published this week in The Condor: Ornithological Applications may have important implications for reducing bird strikes through the customization of aircraft and runway lights to birds' visual systems.

Chemists develop new way to make cost-effective material for electricity storage
University of British Columbia researchers have found a new way to make state-of-the-art materials for energy storage using a cheap lamp from the hardware store.

Carbon nanoballs can greatly contribute to sustainable energy supply
Researchers at Chalmers University of Technology have discovered that the insulation plastic used in high-voltage cables can withstand a 26 per cent higher voltage if nanometer-sized carbon balls are added.

Glass for battery electrodes
For some time now, energy experts have been adamant that we will need much more clean energy in the future if we are to replace fossil fuel sources and reduce CO2 emissions. For example, electric cars will need to replace the petrol-powered cars driving on our roads.
More Wind Turbines Current Events and Wind Turbines News Articles

Wind Turbines: Fundamentals, Technologies, Application, Economics

Wind Turbines: Fundamentals, Technologies, Application, Economics
by Erich Hau (Author), Horst von Renouard (Translator)


Wind Turbines addresses all those professionally involved in research, development, manufacture and operation of wind turbines. It provides a cross-disciplinary overview of modern wind turbine technology and an orientation in the associated technical, economic and environmental fields. It is based on the author's experience gained over decades designing wind energy converters with a major industrial manufacturer and, more recently, in technical consulting and in the planning of large wind park installations, with special attention to economics. The second edition accounts for the emerging concerns over increasing numbers of installed wind turbines. In particular, an important new chapter has been added which deals with offshore wind utilisation. All advanced chapters have been extensively...

Wind Power For Dummies

Wind Power For Dummies
by Ian Woofenden (Author)


The consumer guide to small-scale wind electricity production!

Maybe you're not T. Boone Pickens, but you can build your own home-sized wind-power empire right in your back yard. Wind Power For Dummies supplies all the guidance you need to install and maintain a sustainable, cost-effective wind generator to power your home for decades to come. This authoritative, plain-English guide walks you through every step of the process, from assessing your site and available wind sources to deciding whether wind power is the solution for you, from understanding the mechanics of wind power and locating a contractor to install your system to producing your own affordable and sustainable electricity. Guides you step by step through process of selecting, installing, and operating a...

Build Your Own Small Wind Power System

Build Your Own Small Wind Power System
by Kevin Shea (Author), Brian Clark Howard (Author)


A STEP-BY-STEP GUIDE TO BUILDING A SMALL WIND POWER SYSTEM FROM THE GROUND UP Written by renewable energy experts, this hands-on resource provides the technical information and easy-to-follow instructions you need to harness the wind and generate clean, safe, and reliable energy for on-site use. Build Your Own Small Wind Power System shows you how to install a grid-connected or off-grid residential-scale setup. Get tips for evaluating your site for wind power potential, obtaining permits, financing your project, selecting components, and assembling and maintaining your system. Pictures, diagrams, charts, and graphs illustrate each step along the way. You'll also find out how you can help promote wind-friendly public policies locally. Save money and reduce your carbon footprint with help...

Wind Turbine Technology

Wind Turbine Technology
by A. R. Jha Ph.D. (Author)


Highlighting the capabilities, limitations, and benefits of wind power, Wind Turbine Technology gives you a complete introduction and overview of wind turbine technology and wind farm design and development. It identifies the critical components of a wind turbine, describes the functional capabilities of each component, and examines the latest performance parameters and procurement specifications for these components. From cutting-edge design aspects to experimental data, this comprehensive reference contains eight chapters—each dedicated to a specific design aspect of wind turbine technology. It examines potential wind turbine installation configurations, along with the structural requirements for the tower and nacelle. The book also: Presents site wind speed prediction techniques...

Do-it-Yourself Solar and Wind Energy System: DIY Off-grid and On-grid Solar Panel and Wind Turbine System

Do-it-Yourself Solar and Wind Energy System: DIY Off-grid and On-grid Solar Panel and Wind Turbine System
by Eric Layton (Author)


Eric Layton, a well-known solar expert, wrote this guide for readers that are trying to build their own solar or wind system. Using pictures, this do-it-yourself (DIY) solar and wind system was built with a battery back-up system. His new book is a comprehensive guide on the design, thought process, equipment, and technique on designing this DIY system. Using photographs taken throughout the building process, he covers why he chose certain components in addition to any issues building and installing. This book was written to help fellow solar and wind enthusiasts, as well as inspire those who would like to build their own solar and wind DIY system.

Wind Turbine Technology (Go Green with Renewable Energy Resources)

Wind Turbine Technology (Go Green with Renewable Energy Resources)
by Ahmad Hemami (Author)


Wind energy is a rapidly growing and the demand for trained technicians is high. WIND TURBINE TECHNOLOGY, is a comprehensive and well illustrated book on the theory and operations of wind turbines that generate electricity for power companies. This book is written as an introduction to wind energy technology. It prepares readers for a career as wind energy technicians who are responsible for maintaining, servicing and troubleshooting turbines on wind farms. This is an inclusive book that covers the main subjects associated with wind turbines. Dr. Hemami uses a practical, step-by-step manner with many examples and applications to help you to have a better understanding of the material. The book is divided into 17 progressive chapters. The book is divided into progressive sections,...

Wind Energy Engineering

Wind Energy Engineering
by Pramod Jain (Author)


A PRACTICAL GUIDE TO WIND ENERGY ENGINEERING AND MANAGEMENT This authoritative resource offers comprehensive details on effectively using wind energy as a viable and economical energy source. Featuring a multidisciplinary approach, Wind Energy Engineering covers physics, meteorology, aerodynamics. wind measurement, wind turbine specifications, electricity, and integration with the grid. Planning, site selection, cost assessment, environmental impact, and project management are also discussed. Filled with diagrams, tables, charts, graphs, and statistics, this is a definitive reference to current and future developments in wind energy. Wind Energy Engineering covers: The business of wind energy worldwide Wind energy basics Meteorological properties of wind and air Aerodynamics of...

The Boy Who Harnessed the Wind: Creating Currents of Electricity and Hope (P.S.)

The Boy Who Harnessed the Wind: Creating Currents of Electricity and Hope (P.S.)
by William Kamkwamba (Author), Bryan Mealer (Author)


William Kamkwamba was born in Malawi, a country where magic ruled and modern science was mystery. It was also a land withered by drought and hunger. But William had read about windmills, and he dreamed of building one that would bring to his small village a set of luxuries that only 2 percent of Malawians could enjoy: electricity and running water. His neighbors called him misala—crazy—but William refused to let go of his dreams. With a small pile of once-forgotten science textbooks; some scrap metal, tractor parts, and bicycle halves; and an armory of curiosity and determination, he embarked on a daring plan to forge an unlikely contraption and small miracle that would change the lives around him. The Boy Who Harnessed the Wind is a remarkable true story about human inventiveness and...

Wind Energy Handbook

Wind Energy Handbook
by Tony Burton (Author), Nick Jenkins (Author), David Sharpe (Author), Ervin Bossanyi (Author)


Named as one of Choice's Outstanding Academic Titles of 2012 Every year, Choice subject editors recognise the most significant print and electronic works reviewed in Choice during the previous calendar year. Appearing annually in Choice's January issue, this prestigious list of publications reflects the best in scholarly titles and attracts extraordinary attention from the academic library community. The authoritative reference on wind energy, now fully revised and updated to include offshore wind power A decade on from its first release, the Wind Energy Handbook, Second Edition, reflects the advances in technology underpinning the continued expansion of the global wind power sector. Harnessing their collective industrial and academic expertise, the authors provide a comprehensive...

How to Install a Small to Mid Size Solar & Wind Power Generation System

How to Install a Small to Mid Size Solar & Wind Power Generation System


How to Install a
Small to Mid size
Solar Power and Wind Generation System

Using/Installing Solar Panels plus info on Wind Generator Installation

Most people think that solar power is only used to power huge inverters to attach to the power grid and feed extra power back into the grid. Well yes you can do this IF you have thousands and THOUSANDS of dollars to spend.

Most people don’t even think or realize how much you can do with 12 volt power.
I have 98% of all the lights inside and outside my home are 12 volt LED’s. Most of my LED lights use only 3 watts or 6 watts of power.
I have a 12 volt Evaporative (swamp) Cooler to cool my home on hot summer days.
I have a 12 volt coffee pot to make my coffee in the...

© 2015 BrightSurf.com