Hydrogen Technology Steams Ahead

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ScienceDaily (July 17, 2009) — Could the cars and laptops of the future be fuelled by old chip fat? Engineers at the University of Leeds believe so, and are developing an energy efficient, environmentally-friendly hydrogen production system. The system enables hydrogen to be extracted from waste materials, such as vegetable oil and the glycerol by-product of bio-diesel. The aim is to create the high purity hydrogen-based fuel necessary not only for large-scale power production, but also for smaller portable fuel cells.

Dr Valerie Dupont from the School of Process, Environmental and Materials Engineering (SPEME) says: “I can foresee a time when the processes we are investigating could help ensure that hydrogen is a mainstream fuel.
“We are investigating the feasibility of creating a uniquely energy efficient method of hydrogen production which uses air rather than burners to heat the raw product. Our current research will improve the sustainability of this process and reduce its carbon emissions.”
A grant of over £400k has been awarded to the University by the Engineering and Physical Sciences Research Council (EPSRC) within a consortium of 12 institutions known as SUPERGEN Sustainable Hydrogen Delivery.
Hydrogen is widely considered to be a potential replacement for fossil fuels, but it is costly to extract. There are also often high levels of greenhouse gases emitted during conventional methods of production.
The system being developed at Leeds – known as Unmixed and Sorption-Enhanced Steam Reforming - mixes waste products with steam to release hydrogen and is potentially cheaper, cleaner and more energy efficient.
A hydrocarbon-based fuel from plant or waste sources is mixed with steam in a catalytic reactor, generating hydrogen and carbon dioxide along with excess water. The water is then easily condensed by cooling and the carbon dioxide is removed in-situ by a solid sorbent material.
Dr Dupont says: “It’s becoming increasingly necessary for scientists devising new technologies to limit the amount of carbon dioxide they release. This project takes us one step closer to these goals – once we have technologies that enable us to produce hydrogen sustainably, the infrastructure to support its use will grow.”
“We firmly believe that these advanced steam reforming processes have great potential for helping to build the hydrogen economy. Our primary focus now is to ensure the materials we rely on - both to catalyse the desired reaction and to capture the carbon dioxide – can be used over and over again without losing their efficacy.”
Adapted from materials provided by University of Leeds.

Blind Can Take Wheel With Newly Designed Vehicle

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ScienceDaily (July 15, 2009) — A student team in the Virginia Tech College of Engineering is providing the blind with an opportunity many never thought possible: The opportunity to drive.

A retrofitted four-wheel dirt buggy developed by the Blind Driver Challenge team (http://www.me.vt.edu/blinddriver/) from Virginia Tech's Robotics and Mechanisms Laboratory uses laser range finders, an instant voice command interface and a host of other innovative, cutting-edge technology to guide blind drivers as they steer, brake, and accelerate. Although in the early testing stage, the National Federation of the Blind -- which spurred the project -- considers the vehicle a major breakthrough for independent living of the visually impaired.
"It was great!" said Wes Majerus, of Baltimore, the first blind person to drive the buggy on a closed course at the Virginia Tech campus this summer. Majerus is an access technology specialist with the National Federation of the Blind's Jernigan Institute in Baltimore, a research and training institute dedicated to developing technologies and services to help the blind achieve independence.
Majerus called his drive a liberating experience, adding that he drove before on Nebraska farm roads with his father as a guide in the passenger seat.
Sitting inside the vehicle, a blind driver can turn the steering wheel, stop and accelerate by following data from a computing unit that uses sensory information from the laser range finder serving as the 'eyes' of the driver, in addition to a combination of voice commands and a vibrating vest as guides. A member of the Virginia Tech student team sat next to Majerus in the passenger seat to monitor the system's software operations.
"It's a great first step," Majerus added. "As far as the differences between human instructions and those given by the voice in the Blind Driver Challenge car, the car's instructions are very precise. You use the technology to act on the environment -- the driving course -- in a very orderly manner. In some cases, the human passenger will be vague, "turn left" -- does that mean just a small turn to the left, or are we going for large amounts of turn?"
Also driving the vehicle was Mark Riccobono, also of Baltimore, the executive director of the Jernigan Institute, who also is blind. He called his test drive historic. "This is sort of our going to the moon project," he said
In 2004 Jernigan Institute challenged university research teams to develop a vehicle that would one day allow the blind to drive. Virginia Tech was the only university in the nation to accept the nonprofit's call two years later, said Dennis Hong, director of the Robotics and Mechanisms Laboratory, part of the Virginia Tech mechanical engineering department. The National Federation of the Blind provided a $3,000 grant to launch the project.
"I thought it would be a very rewarding project, helping the blind," said Hong, the current faculty adviser on the project. "We are not only excited about the vehicle itself, but more than that, we are excited about the potential of the many spin-off technologies from this project that can be used for helping the blind in so many ways."
The team will bring the Blind Driver Challenge vehicle to the National Federation of the Blind's Youth Slam summer camp event held July 26 through Aug. 1 in College Park, Md. There, the team hopes to have teenagers who would be obtaining their driver's licenses, but cannot because of their blindness, drive the buggy.
Youth participants also are expected to remote control drive miniature cars. Additionally, the car is expected to ride in a National Federation of the Blind-sponsored parade in Washington D.C.
"I most look forward to learning as much as I can from these bright young students," said Greg Jannaman, who led the Virginia Tech student team in his senior year and graduated in May with a bachelor's degree in mechanical engineering. "Blind students from across the nation apply to be selected to attend this summer camp. While we are there to provide an educational experience for them, I can only imagine the invaluable feedback and fresh new ideas that they will provide in return."
Jannaman is excited about the vehicle's success. "There wasn't a moment's hesitation with any of our blind drivers, whereas blind-folded sighted drivers weren't as quick to let go of their preconceptions," said Jannaman of Hendersonville, Tenn. "The blind drivers actually performed better than their sighted counterparts. An overwhelming sense of accomplishment overcame me as I simply rode along while Wes and Mark successfully navigated the driving course without my assistance."
Early models of the Blind Driver Challenge vehicle relied more on technologies for fully autonomous vehicles, previously developed by Virginia Tech mechanical engineering students as part of the DARPA Urban Challenge (http://www.vt.edu/spotlight/achievement/2007-10-29_victortango/2007-10-29-victortango.html). The student team redesigned the vehicle so that the blind motorist has complete control of the driving process, as any sighted driver would.
This change in approach led to new challenges, including how to effectively convey the high bandwidth of information from the laser sensors scanning the vehicle's surrounding environment to the driver fast enough and accurate enough to allow safe driving. As a result, the team developed non-visual interface technologies, including a vibrating vest for feedback on speed, a click counter steering wheel with audio cues, spoken commands for directional feedback, and a unique tactile map interface that utilizes compressed air to provide information about the road and obstacles surrounding the vehicle.
Riccobono knows of mock ups and non-working "blind driver car" set-ups from the past, but says this is the first working vehicle to put the blind and visually impaired in control of the steering wheel. "Blind people have brains, the capacity to make decisions," he said. "Blind people want to live independent lives, why would they not want to drive?"
Even once the technology is perfected, laws now barring the blind from driving and public perception must be changed, Riccobono said. "This is the piece that we know will be the most difficult," said Riccobono, adding that the car must be near-perfected before the National Federation of the Blind can truly push the car to law-makers and the general public. He said this effort will take millions of dollars in development.
The 2009-10 student team already is planning major changes to the technology, including replacing the dirt buggy vehicle with a fully electric car commonly used by traffic officers in downtown city centers. The all-electric vehicle would reduce the vibration which can cause problems to the laser sensor, and it will provide clean electric power for the computing units and that is better for the environment.
Hong is a National Science Foundation CAREER Award recipient. He received his bachelor's degree in mechanical engineering from the University of Wisconsin-Madison in 1994, and his master's and doctoral degrees in mechanical engineering from Purdue University in 1999 and 2002, respectively.
Adapted from materials provided by Virginia Tech.

Physics Of Bumpy Roads: What Makes Roads Ripple Like A Washboard?

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ScienceDaily (July 9, 2009) — Just about any road with a loose surface — sand or gravel or snow — develops ripples that make driving a very shaky experience. A team of physicists from Canada, France and the United Kingdom have recreated this "washboard" phenomenon in the lab with surprising results: ripples appear even when the springy suspension of the car and the rolling shape of the wheel are eliminated. The discovery may smooth the way to designing improved suspension systems that eliminate the bumpy ride.

"The hopping of the wheel over the ripples turns out to be mathematically similar to skipping a stone over water," says University of Toronto physicist, Stephen Morris, a member of the research team.
"To understand the washboard road effect, we tried to find the simplest instance of it, he explains. We built lab experiments in which we replaced the wheel with a suspension rolling over a road with a simple inclined plow blade, without any spring or suspension, dragging over a bed of dry sand. Ripples appear when the plow moves above a certain threshold speed."
"We analyzed this threshold speed theoretically and found a connection to the physics of stone skipping. A skipping stone needs to go above a specific speed in order to develop enough force to be thrown off the surface of the water. A washboarding plow is quite similar; the main difference is that the sandy surface "remembers" its shape on later passes of the blade, amplifying the effect."
Washboard road is familiar to drivers of back country roads the world over but also appears in some other surprising places in nature and technology. Just about any time a malleable surface is acted upon by a sideways force, you will get ripples. Washboard road is analogous to the little ripples that form on wind- or water-driven sand at the beach, and to the moguls which develop on ski hills. Motocross bikes and snowmobiles also make ripples. Washboard can also cause tiny bumps on steel railway tracks and even the read head in a hard disk can sometimes hop along the surface of the disk to make a washboard pattern.
In addition to Morris, the research collaboration includes lead author Anne-Florence Bitbol and Nicolas Taberlet of Ecole Normale Superieure in Lyon and Jim McElwaine of the University of Cambridge. Experiments were done in Cambridge and Lyon and results published in Physical Review E on June 26, 2009.
Adapted from materials provided by University of Toronto.

Best Possible Cut From Gemstones With New Machine

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ScienceDaily (June 26, 2009) — Emeralds, rubies and the likes are referred to as colored gemstones by experts. They sparkle and shine with varying intensity, depending on the cut. A new machine can achieve the best possible cut and extract up to 30 per cent more precious stone from the raw material.

“We were astounded when our customer, Markus Wild, approached us and we were not at all certain whether mathematics could offer a solution for the very complex problem of volume optimization of gemstones,” says Dr. Anton Winterfeld from the Fraunhofer Institute for Industrial Mathematics ITWM. Jointly with his colleague Dr. Peter Klein, he will receive one of the 2009 Joseph von Fraunhofer prizes for the development of GemOpt, a new industrial process for the volume-optimized utilization of colored gemstones.
In contrast to diamonds, there are innumerable combinations of types and proportions of cut, and types of facet patterns for colored gemstones. When chosen correctly, the interplay of these variables ensures the luster in the stone, its shine. Sometimes just a few facets are sufficient to make a gemstone sparkle, sometimes several hundred. The task was to set limits on what seemed to be infinite and to calculate the optimal volume. The mathematical approach, which finally resulted in a solution, originated from the area of general semi-infinite optimization.
This involved a new type of algorithm, which had until now only been theoretically defined. The team at the ITWM continued to develop this approach and implemented it for this specific problem. The result is an outstanding achievement, also in scientific terms. The second essential part of GemOpt is process control, which Dr. Peter Klein has worked out. For this he ascertained precisely how raw gemstones behave when processed and transferred his findings to the control unit of the machine.
The machine runs fully automatically. First of all, the raw stone is measured. On the basis of these data, the computer calculates optimal embedments, proportions and facet patterns for different basic geometries. The customer then opts for one of the proposed solutions and the machine begins cutting. The process control unit is finely balanced, so that the machine does not split the stones as it cuts them.
The system then moves seamlessly on to the polishing step. The 17 axes ensure that the stone can move along any desired path. The machine cuts the facets to ten micrometers exactly – the stones are therefore perfectly geometric. A further advantage is that the machine can produce identical stones – ideal for necklaces. Cutting with the machine can result in up to 30 per cent more weight. This puts a significantly higher price on the stone.
Adapted from materials provided by Fraunhofer-Gesellschaft.

Getting your V6 to act like a V8, while saving gas

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The history of engine improvements in the U.S. has tended primarily in one direction: raw horsepower. Engines have gotten bigger and more powerful over time—and that's certainly what automakers have used as a key selling point. But U.S. automaker Ford has decided to take turbocharging and direct fuel injection in another direction: fuel efficiency.Yesterday, Ford began production of what it's calling the EcoBoost engine: a new gasoline motor that employs turbocharging, direct fuel injection, variable timing in the valves that control fuel and exhaust flow to make a smaller, lighter six-cylinder engine perform like an eight-cylinder engine.* When these technologies are combined, "you can now significantly downsize the engine," says mechanical engineer Dan Kapp, Ford's director for power train research. "The fuel efficiency comes from a much smaller displacement engine providing equal or, in most cases, superior performance to the engine you're replacing."In essence, the new engine works by using the turbocharging to deliver more air to the fuel burning chamber, variable valve timing to fully flush exhaust gas after combustion in the chamber and then direct injection to overcome any knocking issues.

The company estimates the new engines—which will begin appearing in the Lincoln MKS and MKZ and the Ford Flex and Taurus this summer—can deliver at least 10 percent more miles-per-gallon and therefore reduced emissions of carbon dioxide. By 2013, the company plans to produce 1.3 million vehicles with EcoBoost engines in them, including 90 percent of all Ford vehicles sold in the U.S.Of course, such cars will be more expensive than current models, though Kapp declined to specify a price tag, saying only that fuel savings could pay for it "on the order of two years or less" at today's fuel prices. That’s compared to much longer payback times for diesels or hybrids (which Ford is also producing). Ultimately, the EcoBoost engine will also have to cope with alternative fuels, and Ford plans in the longer-term future to move more towards hybrids and electric vehicles. But for the next decade or so, Ford will be relying on these engines to meet some of the new fuel efficiency targets announced this week and reduce pollution. "What Ford is doing uniquely here is leveraging [EcoBoost] to deliver fuel efficiency through aggressive downsizing [of the engine] as opposed to the performance type approach," Kapp says. But it remains to be seen whether a car company that has spent years and millions of advertising dollars touting the horsepower that can be gained from such improvements (at the expense of fuel efficiency) can convince customers to change direction too.
Image 1: Lincoln MKZ engine. Copyright 2009—Ford Motor Company and Wieck Photo Database

Battery-powered Vehicles To Be Revolutionized By New Technology

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ScienceDaily (May 11, 2009) — Thousands of small electric scooters, bicycles and wheelchairs throughout Europe and Asia are powered by LifePO4 –- a material used in advanced lithium-ion batteries developed by Université de Montréal researchers.

"It's a revolutionary battery because it is made from non-toxic materials abundant in the Earth's crust. Plus, it's not expensive,'" says Michel Gauthier, an invited professor at the Université de Montréal Department of Chemistry and co-founder of Phostech Lithium, the company that makes the battery material. "This battery could eventually make the electric car very profitable."
The theory will soon be tested, since the 100 percent electric Microcar that's set to debut in Europe this year will be and powered by the LifePO4 battery.
Phostech Lithium's production plant in St. Bruno, Quebec, produces the black LifePO4 powder, which is shipped across the world in tightly sealed barrels.
"The theoretical principle behind the battery was patented by a University of Texas professor in 1995. However, without the work of local chemists such as Nathalie Ravet, we couldn't have developed it," says Phostech Lithium engineer Denis Geoffroy.
Süd-Chemie, a leading specialty chemistry company based in Germany, first invested in Phostech Lithium in 2005. Now, just four years later, Süd-Chemie's total Canadian investments have reached $13 million and it stands as the 100% owner of Phostech Lithium. Phostech's St. Bruno plant began to produce LiFePO4 in 2006 with 20 employees and a 400 metric-ton capacity. Since then, Phostech has nearly doubled its staff.
"It is a battery that is much more stable and much safer," says Dean MacNeil, a professor at the Université de Montréal's Department of Chemistry and new NSERC-Phostech Lithium Industrial Research Chair in Energy Storage and Conversion. "In addition, it recharges much faster than previous batteries."
The NSERC Research Chair, funded in part by Phostech Lithium, will help investigate ways to improve the LifePO4 battery.
For Gauthier, Phostech Lithium is the product of academia and the business world coming together. "Even if we knew that lithium, iron and phosphate were theoretically promising materials, we had to make them efficient. We had to find the right voltage and maintain the right charging and discharging properties. This is where the university played a major role."
Adapted from materials provided by University of Montreal.

Will America's Power Grid Be Able To Keep Pace With Future Demand?

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ScienceDaily (May 8, 2009) — America's power grid today resembles the country's canal system of the 19th Century. A marvel of engineering for its time, the canal system eventually could not keep pace with the growing demands of transcontinental transportation.

More than 150 years later, America's infrastructure is again changing in ways that its designers never anticipated. Distributed and intermittent electricity generation, such as wind power, is rapidly expanding, new smart meters are giving consumers more control over their energy usage, and plug-in hybrid electric vehicles may someday radically increase the overall demand for electricity.
The evolution of America's energy needs has forced scientists and engineers to re-examine the operations, efficiency and security of the national power grid. The creation of a more secure and efficient national power grid requires significant innovations in the way we transmit electricity and monitor its use.
To better assess the challenges facing the power grid, the U.S. Department of Energy's (DOE) Argonne National Laboratory hosted a workshop that brought together power system and modeling experts from federal agencies, national laboratories and academia.
"Modeling and simulation have proved to be effective tools for the power industry on many levels," said Mark Petri, Argonne's technology development director and one of the workshop's organizers. "We need to develop a comprehensive and integrated approach that will enable us to better understand the full implications of an evolving power grid as we plan for future demand and power sources."
The workshop centered on the need for new methods to simulate the national power grid by modeling the creation and flow of electric power as well as the grid's connection to other critical infrastructures, such as transportation, gas, water and communications. Through detailed simulations of how electric power is supplied and transferred around the country, researchers can bolster not only the grid's security but also its reliability, efficiency and resiliency.
"Implementing smart grid technologies on a large scale will not be trivial," Petri added. "The challenges go beyond technical and economic issues. The smart grid technologies could fundamentally change how national power grid systems operate and respond to disruptions."
Because of the great diversity of ways in which electricity is created, distributed and consumed, engineers face a challenge in creating reliable models of large power networks. They have to deal with the intermittent nature of some of the sources (like wind or solar), optimize how power is transmitted and balance economic, security and environmental priorities when finding solutions.
"In the short-term," Petri said, "these simulations could help devise ways to solve the problem of grid congestion, which currently costs consumers many hundreds of millions of dollars each year. Even small improvements in grid efficiency that better models and simulations would produce would make the investment cost-effective."
The workshop, which was sponsored by U.S. Department of Homeland Security Science and Technology Directorate, identified barriers that a national grid simulation capability would need to overcome to be effective. The findings of the workshop appear in the report "National Power Grid Simulation Capability: Needs and Issues." According to Petri, an operational plan for a national power grid simulation capability that engages industry to better understand their needs, capabilities and concerns would support a more secure and reliable electric power grid system for the future.
Adapted from materials provided by DOE/Argonne National Laboratory.

Animals On Runways Can Cause Serious Problems At Small Airports

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ScienceDaily (May 9, 2009) — It's a bird. It's a plane. It's a potentially deadly combination.

A Purdue University study of 10 small Indiana airports found that animals can gain easy access to runways and infield areas, increasing the likelihood of planes striking those animals.
Animal strikes received national attention in January. Commercial pilot and Purdue alumnus Charles "Sully" Sullenberger was forced to land in the Hudson River after his plane hit a flock of Canada geese.
The study by Gene Rhodes, a professor of forestry and natural resources, documented that animals found ways through damaged fences or unfenced areas onto airport properties. Spotting deer, coyote and other animals in dangerous places was common.
"Just about every pilot we talked to at these airports said that during a landing they've had to pull up to avoid hitting an animal on the runway," Rhodes said. "With the size of planes using these airports, hitting a rabbit could flip a plane."
While Rhodes' study looked only at Indiana airports, he said there are thousands of airports all over the country that don't have the budgets to adequately fence their properties, endangering countless flights each year.
In the study, only four of the Indiana airports had fences around the entire perimeter, and even those had maintenance problems - such as holes dug under fences, access through culverts and holes in fences - that allowed animals onto the properties.
Despite the desire to keep animals away, Rhodes said airports often are a magnet for wildlife. Airports are required to own property around runways that is often rented to farmers. While that increases airports' meager budgets, those crops can attract animals looking for food.
"What you have planted affects what type of animals will be there," Rhodes said. "Even if you have certain grasses, you have small mammals that eat those, and those attract red-tailed hawks. A red-tailed hawk can bring down a small plane as fast as anything."
Previous studies cited in Rhodes' paper have shown that wildlife strikes cost more than a half a billion dollars each year and have been responsible for more than 350 human deaths in the last century. Travis DeVault, who co-authored the paper as Rhodes' postdoctoral researcher and is now a field station and project leader with the U.S. Department of Agriculture's Wildlife Services, said wildlife strikes have become more common in recent years.
"Many of the most hazardous species are increasing in population size. For example, about two-thirds of the largest bird species have shown population increases during the past 30 years," DeVault said. "Also, air traffic continues to increase. More birds in combination with more flights leads to more bird strikes."
DeVault added that new technology means planes are quieter today, giving birds less time to detect and avoid being struck.
Rhodes' study suggests enclosing 100 percent of airport perimeters with partially buried fencing, which keeps animals from tunneling underneath. Frequent maintenance also is key because many of the animals observed during the study entered the airports through damaged fences.
"If airports can use this study to show their needs, it can allow them to go after federal grants they need to make improvements," Rhodes said.
The Joint Transportation Research Program of the Indiana Department of Transportation and the Aviation Association of Indiana funded the research. Rhodes said the next step is to determine viable economic uses that also will deter wildlife from the land around airports.
Journal reference:
Travis L. DeVault, Jacob E. Kubel, David J. Glista and Olin E. Rhodes Jr. Mammalian Hazards at Small Airports in Indiana: Impact of Perimeter Fencing. Human-Wildlife Conflicts, Fall 2008
Adapted from materials provided by Purdue University.

Bioelectricity Promises More 'Miles Per Acre' Than Ethanol

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ScienceDaily (May 8, 2009) — Biofuels such as ethanol offer an alternative to petroleum for powering our cars, but growing energy crops to produce them can compete with food crops for farmland, and clearing forests to expand farmland will aggravate the climate change problem. How can we maximize our "miles per acre" from biomass?

Researchers writing in the online edition of the journal Science on May 7 say the best bet is to convert the biomass to electricity, rather than ethanol. They calculate that, compared to ethanol used for internal combustion engines, bioelectricity used for battery-powered vehicles would deliver an average of 80% more miles of transportation per acre of crops, while also providing double the greenhouse gas offsets to mitigate climate change.
"It's a relatively obvious question once you ask it, but nobody had really asked it before," says study co-author Chris Field, director of the Department of Global Ecology at the Carnegie Institution. "The kinds of motivations that have driven people to think about developing ethanol as a vehicle fuel have been somewhat different from those that have been motivating people to think about battery electric vehicles, but the overlap is in the area of maximizing efficiency and minimizing adverse impacts on climate."
Field, who is also a professor of biology at Stanford University and a senior fellow at Stanford's Woods Institute for the Environment, is part of a research team that includes lead author Elliott Campbell of the University of California, Merced, and David Lobell of Stanford's Program on Food Security and the Environment. The researchers performed a life-cycle analysis of both bioelectricity and ethanol technologies, taking into account not only the energy produced by each technology, but also the energy consumed in producing the vehicles and fuels. For the analysis, they used publicly available data on vehicle efficiencies from the US Environmental Protection Agency and other organizations.
Bioelectricity was the clear winner in the transportation-miles-per-acre comparison, regardless of whether the energy was produced from corn or from switchgrass, a cellulose-based energy crop. For example, a small SUV powered by bioelectricity could travel nearly 14,000 highway miles on the net energy produced from an acre of switchgrass, while a comparable internal combustion vehicle could only travel about 9,000 miles on the highway. (Average mileage for both city and highway driving would be 15,000 miles for a biolelectric SUV and 8,000 miles for an internal combustion vehicle.)
"The internal combustion engine just isn't very efficient, especially when compared to electric vehicles," says Campbell. "Even the best ethanol-producing technologies with hybrid vehicles aren't enough to overcome this."
The researchers found that bioelectricity and ethanol also differed in their potential impact on climate change. "Some approaches to bioenergy can make climate change worse, but other limited approaches can help fight climate change," says Campbell. "For these beneficial approaches, we could do more to fight climate change by making electricity than making ethanol."
The energy from an acre of switchgrass used to power an electric vehicle would prevent or offset the release of up to 10 tons of CO2 per acre, relative to a similar-sized gasoline-powered car. Across vehicle types and different crops, this offset averages more than 100% larger for the bioelectricity than for the ethanol pathway. Bioelectricity also offers more possibilities for reducing greenhouse gas emissions through measures such as carbon capture and sequestration, which could be implemented at biomass power stations but not individual internal combustion vehicles.
While the results of the study clearly favor bioelectricity over ethanol, the researchers caution that the issues facing society in choosing an energy strategy are complex. "We found that converting biomass to electricity rather than ethanol makes the most sense for two policy-relevant issues: transportation and climate," says Lobell. "But we also need to compare these options for other issues like water consumption, air pollution, and economic costs."
"There is a big strategic decision our country and others are making: whether to encourage development of vehicles that run on ethanol or electricity," says Campbell. "Studies like ours could be used to ensure that the alternative energy pathways we chose will provide the most transportation energy and the least climate change impacts."
This research was funded through a grant from the Stanford University Global Climate and Energy Project, with additional support from the Stanford University Food Security and Environment Project, The University of California at Merced, the Carnegie Institution for Science, and a NASA New Investigator Grant. .
* to be published in the May 22, 2009 print edition.
Journal reference:
J. E. Campbell, D. B. Lobell, and C. B. Field. Greater Transportation Energy and GHG Offsets from Bioelectricity Than Ethanol. Science, 2009; DOI: 10.1126/science.1168885
Adapted from materials provided by Carnegie Institution.

'Smart Turbine Blades' To Improve Wind Power

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ScienceDaily (May 8, 2009) — Researchers have developed a technique that uses sensors and computational software to constantly monitor forces exerted on wind turbine blades, a step toward improving efficiency by adjusting for rapidly changing wind conditions.

The research by engineers at Purdue University and Sandia National Laboratories is part of an effort to develop a smarter wind turbine structure.
"The ultimate goal is to feed information from sensors into an active control system that precisely adjusts components to optimize efficiency," said Purdue doctoral student Jonathan White, who is leading the research with Douglas Adams, a professor of mechanical engineering and director of Purdue's Center for Systems Integrity.
The system also could help improve wind turbine reliability by providing critical real-time information to the control system to prevent catastrophic wind turbine damage from high winds.
"Wind energy is playing an increasing role in providing electrical power," Adams said. "The United States is now the largest harvester of wind energy in the world. The question is, what can be done to wind turbines to make them more efficient, more cost effective and more reliable?"
The engineers embedded sensors called uniaxial and triaxial accelerometers inside a wind turbine blade as the blade was being built. The blade is now being tested on a research wind turbine at the U.S. Department of Agriculture's Agriculture Research Service laboratory in Bushland, Texas. Personnel from Sandia and the USDA operate the research wind turbines at the Texas site.
Such sensors could be instrumental in future turbine blades that have "control surfaces" and simple flaps like those on an airplane's wings to change the aerodynamic characteristics of the blades for better control. Because these flaps would be changed in real time to respond to changing winds, constant sensor data would be critical.
"This is a perfect example of a partnership between a national lab and an academic institution to develop innovations by leveraging the expertise of both," said Jose R. Zayas, manager of Sandia's Wind Energy Technology Department.
Research findings show that using a trio of sensors and "estimator model" software developed by White accurately reveals how much force is being exerted on the blades. Purdue and Sandia have applied for a provisional patent on the technique.
Findings are detailed in a paper being presented May 4 during the Windpower 2009 Conference & Exhibition in Chicago. The paper was written by White, Adams and Sandia engineer Mark A. Rumsey and Zayas. The four-day conference, organized by the American Wind Energy Association, attracts thousands of attendees and is geared toward industry.
"Industry is most interested in identifying loads, or forces, exerted on turbine blades and predicting fatigue, and this work is a step toward accomplishing that," White said.
A wind turbine's major components include rotor blades, a gearbox and generator. The wind turbine blades are made primarily of fiberglass and balsa wood and occasionally are strengthened with carbon fiber.
"The aim is to operate the generator and the turbine in the most efficient way, but this is difficult because wind speeds fluctuate," Adams said. "You want to be able to control the generator or the pitch of the blades to optimize energy capture by reducing forces on the components in the wind turbine during excessively high winds and increase the loads during low winds. In addition to improving efficiency, this should help improve reliability. The wind turbine towers can be 200 feet tall or more, so it is very expensive to service and repair damaged components."
Sensor data in a smart system might be used to better control the turbine speed by automatically adjusting the blade pitch while also commanding the generator to take corrective steps.
"We envision smart systems being a potentially huge step forward for turbines," said Sandia's Rumsey. "There is still a lot of work to be done, but we believe the payoff will be great. Our goal is to provide the electric utility industry with a reliable and efficient product. We are laying the groundwork for the wind turbine of the future."
Sensor data also will be used to design more resilient blades.
The sensors are capable of measuring acceleration occurring in various directions, which is necessary to accurately characterize the blade's bending and twisting and small vibrations near the tip that eventually cause fatigue and possible failure.
The sensors also measure two types of acceleration. One type, the dynamic acceleration, results from gusting winds, while the other, called static acceleration, results from gravity and the steady background winds. It is essential to accurately measure both forms of acceleration to estimate forces exerted on the blades. The sensor data reveal precisely how much a blade bends and twists from winds.
The research is ongoing, and the engineers are now pursuing the application of their system to advanced, next-generation turbine blades that are more curved than conventional blades. This more complex shape makes it more challenging to apply the technique.
In 2008 the United States added 8,358 megawatts of new wind-power capacity, which equates to thousands of new turbines since the average wind turbine generates 1.5 megawatts. The new capacity increased the total U.S. installed wind power to 25,170 megawatts, surpassing Germany's capacity as the world's largest harvester of wind power.
"Our aim is to do two things - improve reliability and prevent failure - and the most direct way to enable those two capabilities is by monitoring forces exerted on the blades by winds," Adams said.
The research is funded by the U.S. Department of Energy through Sandia National Laboratories. Sandia is a multiprogram laboratory operated by Sandia Corp., a Lockheed Martin Co., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
Journal reference:
White et al. Operational load estimation of a smart wind turbine rotor blade. Proceedings of SPIE, 2009; 72952D DOI: 10.1117/12.815802
Adapted from materials provided by Purdue University.

Scientists Test System To Steer Drivers Away From Dangerous Weather

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ScienceDaily (Apr. 11, 2009) — Scientists at the National Center for Atmospheric Research (NCAR) are testing an innovative technological system in the Detroit area this month that ultimately will help protect drivers from being surprised by black ice, fog, and other hazardous weather conditions.

The prototype system is designed to gather detailed information about weather and road conditions from moving vehicles. Within about a decade, it should enable motor vehicles equipped with wireless technology to transmit automated updates about local conditions to a central database, which will then relay alerts to other drivers in the area.
"The goal is to reduce crashes, injuries, and deaths by getting drivers the information they need about nearby hazards," says Sheldon Drobot, the NCAR program manager in charge of the project. "The system will tell drivers what they can expect to run into in the next few seconds and minutes, giving them a critical chance to slow down or take other action."
NCAR's road weather system is part of IntelliDrive(SM), a national initiative overseen by the Department of Transportation (DOT) to use new technologies to make driving safer and improve mobility. Officials envision that, over the next 10 years or so, motor vehicles will begin to automatically communicate with each other and central databases, alerting drivers to threats that range from adverse road conditions to nearby vehicles that are moving erratically or are running through a red light. The goal of the DOT is to reduce motor vehicle accidents by 90 percent by 2030.
The national program brings together federal and state transportation officials, motor vehicle manufacturers, engineering and planning firms, consumer electronics companies, and others.
An estimated 1.5 million motor vehicle accidents annually are associated with poor weather, resulting in about 7,400 deaths and 690,000 injuries, according to a 2004 National Research Council report, "Where the Weather Meets the Road." The report called for improving safety by establishing a nationwide observation system to monitor weather conditions along roads and warn drivers about potential hazards.
For the road weather portion of IntelliDrive, vehicles will use sensors to measure atmospheric conditions such as temperature, pressure, and humidity. An onboard digital memory device will record that information, along with indirect signs of road conditions, such as windshield wipers being switched on or activation of the antilock braking system.
The information will be transmitted to a central database, where it will be integrated with other local weather data and traffic observations, as well as details about road material and alignment. The processed data will then be used to update motorists in the area when hazards are present and, when appropriate, suggest alternate routes.
The incoming data would be anonymous. Officials are working on guidelines to allow drivers to opt out of the system for privacy considerations.
In addition to providing motorist warnings, such a system will alert emergency managers to hazardous driving conditions and enable state highway departments to efficiently keep roads clear of snow. It can also help meteorologists refine their forecasts by providing them with continual updates about local weather conditions.
Motor vehicle manufacturers plan to install the onboard equipment in every new vehicle sold in the United States within a few years as part of a voluntary program to improve driving safety.
On the prowl for bad weather
NCAR scientists and engineers are testing the weather piece of the system by collecting information from 11 specially equipped cars in the Detroit area. Test drivers are on the prowl for adverse conditions, especially heavy rain and snow. Engineers will analyze the reliability of the system by comparing data from the cars with other observations from radars and weather satellites. They will also look at whether different models of cars-in this case, Jeep Cherokees, Ford Edges, and a Nissan Altima - produce comparable measurements of weather and road conditions.
The tests, which began early this month and will run for about two weeks, will help the NCAR team refine its software to accurately process data from motor vehicles. In the future, the team also hopes to study which types of weather information will be most useful and how that information can be clearly and safely communicated to drivers, possibly through a visual display or audio alert.
"The results look very encouraging," Drobot says. "The tests show that cars can indeed communicate critical information about weather conditions and road hazards."
Processing a deluge of observations
One of the biggest challenges for NCAR is to determine how to process the enormous amounts of data that could be generated by about 300 million motor vehicles. The center has worked with the Department of Defense, the aviation industry, and other organizations to analyze complex weather observations. But the new system incorporates information from far more sources, and those sources are moving.
NCAR engineers are developing mathematical formulas and other techniques to accurately interpret the information and eliminate misleading indicators. If a driver, for example, turns on the windshield wipers in clear weather to clean the windshield, the NCAR data system will identify that action as an outlier rather than issuing a false alert about precipitation.
"It's not enough to process the information almost instantaneously," says William Mahoney, who oversees the system's development for NCAR. "It needs to be cleaned up, sent through a quality control process, blended with traditional weather data, and eventually delivered back to drivers who are counting on the system to accurately guide them through potentially dangerous conditions."
IntelliDrive is a service mark of the U.S. Department of Transportation.
Adapted from materials provided by National Center for Atmospheric Research (NCAR).

Controllable Rubber Trailing Edge Flap To Reduce Loads On Wind Turbine Blades

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ScienceDaily (Mar. 17, 2009) — The trailing edge of wind turbine blades can be manufactured in an elastic material that makes it possible to control the shape of the trailing edge. This will reduce the considerably dynamic loads that large wind turbine blades are exposed to during operation.

”Providing the blade with a movable trailing edge it is possible to control the load on the blade and extend the life time of the wind turbine components. This is similar to the technique used on aircrafts, where flaps regulate the lift during the most critical times such as at take-off and landing, "explains Helge Aagaard Madsen, Research Specialist on the project.
However, there is a difference. Whereas on aircrafts, movable flaps are non-deformable elements hinged to the trailing edge of the main wing, this new technique means a continuous surface of the profile on the wind turbine blade even when the trailing edge moves. The reason for this is that the trailing edge is constructed in elastic material and constitutes an integrated part of the main blade.
Robust design of rubber
In 2004 Risø DTU applied for the first patent for this basic technique of designing a flexible, movable trailing edge for a wind turbine blade. Since then there has been a significant development with regard to the project. By means of so-called "Gap-funding" provided by the Ministry of Science, Technology and Innovation and by the local Region Zealand it has been possible to develop such ideas into a prototype stage.
Part of the research has been aimed at the design and development of a robust controllable trailing edge. This has now led to the manufacturing of a trailing edge of rubber with built-in cavities that are fibre-reinforced. The cavities in combination with the directional fibre reinforcement provide the desired movement of the trailing edge, when the cavities are being put under pressure by air or water.
“In this project a number of different prototypes have been manufactured with a chord length of 15 cm and a length of 30 cm. The best version shows very promising results in terms of deflection and in terms of the speed of the deflection” says Helge Aagaard.
The size of the protype fits a blade airfoil section with a chord of one metre and such a blade section is now being produced and is going to be tested inside a wind tunnel.
The capability of the trailing edge to control the load on the blade section is going to be tested in a wind tunnel. This part of the development process is supported by GAP-funding from Region Zealand.
”If the results confirm our estimated performance, we will test the rubber trailing edge on a full-scale wind turbine within a few years” says Helge Aagaard.
Adapted from materials provided by Risø National Laboratory for Sustainable Energy.

New Design Means Cheaper, More Sustainable Construction

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ScienceDaily (Mar. 11, 2009) — People are always looking for ways to make something less expensive and more environmentally friendly – and a team of researchers from North Carolina State University has figured out how to do both of those things at once when raising the large-scale buildings, such as parking garages, of the future.

More specifically, the researchers have figured out a way to use 30 percent less reinforcing steel in the manufacture of the concrete beams, or spandrels, used in the construction of parking garages – without sacrificing safety. Dr. Sami Rizkalla, one of the leaders of the research team, says they developed design guidelines that use less steel while maintaining safety and reliability. The new spandrel design "simplifies construction for precast concrete producers," Rizkalla says. In addition to using less steel, the new design cuts labor and manufacturing time in half – significantly decreasing costs.
Greg Lucier, a doctoral student at NC State who was also crucial to the research effort, says the new design guidelines include a significant margin for safety. For example, Lucier says the spandrels could handle two to three times the maximum weight they would be expected to bear. Lucier is also the lab manager of the Constructed Facilities Laboratory at NC State, which oversaw the testing of the new spandrel design.
The new design guidelines stem from a two-year project that was launched in January 2007, with support from the Precast/Prestressed Concrete Institute (PCI). PCI provided NC State with more than $400,000 in funding, materials and technical support over the life of the project.
The success of the project is already drawing interest from the concrete industry, with individual companies coming to NC State to get input on how to improve their products and manufacturing processes. For example, Rizkalla says, many companies want to collaborate with researchers at the Constructed Facilities Laboratory on research and development projects related to new materials, such as advanced composites, to be used in concrete products.
While researchers have published some elements of the research project, they will present an overview of the entire project – including new testing data – for the first time at the spring convention of the American Concrete Institute in San Antonio this month.
Adapted from materials provided by North Carolina State University.