Solar panel manufacturing is greener in Europe than China, study says

 

May 29 / 2014

DOE/Argonne National Laboratory

Solar panels made in China have a higher overall carbon footprint and are likely to use substantially more energy during manufacturing than those made in Europe, said a new study. The team performed a type of systematic evaluation called life cycle analysis to come up with these hard data. Life cycle analysis tallies up all the energy used to make a product -- energy to mine raw materials, fuel to transport the materials and products, electricity to power the processing factory, and so forth.

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A new study by Argonne and Northwestern scientists reported that solar panels manufactured in China are likely to use more energy to make and have a larger carbon footprint than those made in Europe.

Solar panels made in China have a higher overall carbon footprint and are likely to use substantially more energy during manufacturing than those made in Europe, said a new study from Northwestern University and the U.S. Department of Energy's Argonne National Laboratory. The report compared energy and greenhouse gas emissions that go into the manufacturing process of solar panels in Europe and China.

"We estimated that a solar panel's carbon footprint is about twice as high when made in China and used in Europe, compared to those locally made and used in Europe," said Fengqi You, assistant professor of chemical and biological engineering at Northwestern and corresponding author on the paper.

"While it might be an economically attractive option to move solar panel manufacturing from Europe to China, it is actually less sustainable from the life cycle energy and environmental perspective -- especially under the motivation of using solar panels for a more sustainable future," he said.

The team performed a type of systematic evaluation called life cycle analysis to come up with these hard data. Life cycle analysis tallies up all the energy used to make a product -- energy to mine raw materials, fuel to transport the materials and products, electricity to power the processing factory, and so forth. This provides a more accurate picture of the overall energy consumed and produced and the environmental impact of making and using a solar panel.

Assuming that a solar panel is made of silicon -- by far the most common solar panel material -- and is installed in sunny southern Europe, a solar panel made in China would take about 20 to 30 percent longer to produce enough energy to cancel out the energy used to make it. The carbon footprint is about twice as high.

The biggest reason is that China has fewer environmental and efficiency standards for its factories and plants and generates more electricity from coal and other non-renewable sources, the authors said.

"It takes a lot of energy to extract and process solar-grade silicon, and in China, that energy tends to come from dirtier and less efficient energy sources than it does in Europe," said Argonne scientist and co-author Seth Darling. "This gap will likely close over time as China strengthens environmental regulations."

The study did not include the energy cost of transporting a solar panel to its final destination. Transportation would magnify the difference even further if it -- like 60 percent of all solar installations in 2012 -- went up in Germany or Italy, Darling said.

The team also compared the numbers for different types of silicon solar panels. Single-crystal solar panels are better at harvesting energy than other types, but take the longest to "pay back" the energy used to manufacture them because the process is more energy-intensive. Multicrystalline panels came next, followed by ribbon silicon panels, which are easiest to manufacture but least efficient -- however, their payback time was fastest.

To encourage more sustainable production of solar cells, the authors suggest a break-even carbon tariff. "This would be based on the carbon footprint and energy efficiency difference between manufacturing regions, and would be a better market- and science-based solution than a solar panel tariff," said Dajun Yue, a Northwestern graduate student in You's research group and lead author on the paper.

"The break-even carbon tariff we calculated, which is at the range of €105-129 per ton of carbon dioxide, depending on the possible carbon tax to be imposed by these two regions in the near term, is close to the reported CO₂ capture and sequestration cost," You said.

Funding for this research was provided by the Institute for Sustainability and Energy at Northwestern University. The research was performed in part at the Center for Nanoscale Materials, a U.S. Department of Energy user facility.

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Story Source:

The above story is based on materials provided by DOE/Argonne National Laboratory. The original article was written by Louise Lerner. Note: Materials may be edited for content and length.

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Journal Reference:

1. Dajun Yue, Fengqi You, Seth B. Darling. Domestic and overseas manufacturing scenarios of silicon-based photovoltaics: Life cycle energy and environmental comparative analysis. Solar Energy, 2014; 105: 669 DOI: 10.1016/j.solener.2014.04.008

Fiscally Healthy: Eating Your Vegetables Saves You Money

 

by U.S. News May 31st 2014 6:00AM

Bellena/Shutterstock By Lacie Glover

When it comes to health and finances, not everybody gets the connections with vegetables:

• Eating plenty of vegetables is good for your body, and in a way, your body runs like a bank account: Calories are deposited, and calories are spent. Too many calories spent, and you're hungry and overdrawn. Too many calories deposited, and you're bloated and eventually overweight. Of course, we would all rather have an extra bulge in our bank accounts than at our waistlines.
• Eating plenty of vegetables can also be good for your real-life bank account by saving you money in the long run over a diet packed with junk.

Micronutrients
For many habitually healthy eaters, a fast-food hamburger can feel like a brick in their stomachs. When compared to how it feels to eat clean and green and thriving on natural foods, the difference can seem like night and day. Fruits and vegetables have essential dietary fiber that helps your body run optimally and vitamins and minerals that help make you feel great. Sure, you could just buy a bunch of pills and supplements to get most vitamins and minerals, but spending a lot of money on supplements is a great way to go broke. Besides, you'll sell yourself short on more than just fiber.
The term "micronutrients" refers to small nutritional compounds that can't be categorized as carbs, protein or fats. Micronutrients encompass vitamins, minerals and phytochemicals, which are compounds such as antioxidants, carotenoids and polyphenols. The protective benefits of phytochemicals are just beginning to be researched, although emerging data strongly suggest that many have preventive powers when it comes to cancer and other diseases. Since almost every disease costs money -– and almost any kind of cancer will cost thousands –- this is one way to protect your health and bank account in the future.
Unlike phytochemicals, which generally aren't available in pill form, vitamins and minerals of almost any kind can be bought in bulk. However, not all delivery systems are created equal. Most vitamins and minerals are absorbed better when eaten in whole food form, according to current research. Plus, synthetic supplement versions of nutrients such as calcium and vitamin E may cause health problems down the road that are both painful and costly.
Weight Regulation
It's no secret that obesity has been linked to a litany of health problems, but lesser known is the cost of those diseases. Costs linked to obesity in the U.S. are estimated at $147 billion annually, according to the federal government. Not only that, but normal-weight individuals also tend to make more money than their overweight and obese counterparts and take fewer days off from work. Also, overweight and obese people have higher premiums for both life and health insurance.
Eating lots of vegetables can help you lose weight. Research has shown that people who weigh less tend to eat more fruits and vegetables on a regular basis than overweight individuals. Maybe it's because you can eat a much higher volume for relatively fewer calories by eating filling, low-calorie vegetables –- or even high-calorie vegetables for that matter -– but vegetables also have staying power that other foods don't. Amelia Eisen, a San Francisco health coach who specializes in healthy eating on a budget, tells her clients to stock up on vegetables. "Since they contain high amounts of nutrients, fiber and water, they will satiate and hydrate you, keeping you fuller longer, so you will inevitably eat [less] and spend less on food if you eat more vegetables."
To save money buying vegetables, try these tips:

• Shop at local farmers markets. When you buy local, costs are always lower because the food doesn't travel as far.
• Find recipes before shopping, and stick to the ingredient amounts so you won't buy more than you need.
• Make big meals and freeze leftovers for later. Most vegetables freeze well.
• Stick to in-season vegetables, which are always cheaper.
• Chop and freeze vegetables, which are cheaper than prechopped, frozen vegetables.
• Grow your own vegetables.

To save even more, go vegetarian one day a week. You'll save money without missing out on a lot of protein, and you'll be cutting your saturated fat intake.

Caught by a hair: Quick, new identification of hair may help crime fighters

 

May 29, 2014

Queen's University

Crime fighters could have a new tool at their disposal. Researchers have developed a cutting-edge technique to identify human hair. Their test is quicker than DNA analysis techniques currently used by law enforcement. Early sample testing produced a 100 percent success rate. Blood samples are often used to identify gender and ethnicity, but blood can deteriorate quickly and can easily be contaminated. Hair, on the other hand, is very stable. Elements in hair originate from sweat secretions that alter with diet, ethnicity, gender, the environment and working conditions.

 

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Lily Huang crushes up the human hair prior to testing.

Crime fighters could have a new tool at their disposal following promising research by Queen's professor Diane Beauchemin.

Dr. Beauchemin (Chemistry) and student Lily Huang (MSc'15) have developed a cutting-edge technique to identify human hair. Their test is quicker than DNA analysis techniques currently used by law enforcement. Early sample testing at Queen's produced a 100 per cent success rate.

"My first paper and foray into forensic chemistry was developing a method of identifying paint that could help solve hit and run cases," explains Dr. Beauchemin. "Last year, Lily wanted to research hair analysis, so I started working in that area."

Blood samples are often used to identify gender and ethnicity, but blood can deteriorate quickly and can easily be contaminated. Hair, on the other hand, is very stable. Elements in hair originate from sweat secretions that alter with diet, ethnicity, gender, the environment and working conditions.

Dr. Beauchemin's process takes 85 seconds to complete and involves grinding up the hair, burning it and then analyzing the vapour that is produced.

"Our analysis process is very robust and can be used universally," says Ms. Huang. "One of our samples even included dyed hair and the test was 100 per cent accurate. The test was able to distinguish East Asians, Caucasians and South Asians."

Dr. Beauchemin says she has contacted law enforcement agencies about using the new technology. She is also planning to collect more hair samples and continue her research with a goal of pinpointing where exactly in the world the hair sample is from, to look for more ethnicities and determine specific age.

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Story Source:

The above story is based on materials provided by Queen's University. The original article was written by Anne Craig. Note: Materials may be edited for content and length.

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Journal Reference:

1. Lily Huang, Diane Beauchemin. Ethnic background and gender identification using electrothermal vaporization coupled to inductively coupled plasma optical emission spectrometry for forensic analysis of human hair. Journal of Analytical Atomic Spectrometry, 2014; DOI: 10.1039/c4ja00071d

Knowledge or entertainment: Which would you pay for?

 

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From firewalls to metered access, news organisations have invented many ways to make readers pay for their content online. But the vital question of which readers are more willing to pay than others has been largely neglected -- until now.

Over 500 American adults were asked what factors affect their willingness to pay in a study by Manuel Goyanes, from the Universidad Carlos III de Madrid. Before revealing his results in the current issue of Journalism Practice, Goyanes explains just what the paid online news model is up against, stating that "[This] study shows that online users were more likely to pay for those digital products whose main value proposition consists of providing entertainment (music) and solutions (software and apps), but less likely to pay for those providing knowledge (such as an online newspaper)."

Ultimately, Goyanes found that younger and wealthier users were more likely to be willing to pay for online news, as were moderate users of Twitter; heavy Twitter users were more likely to buy into the "culture of free." People who've bought software programmes, online movies, apps or ebooks are also more likely to pay for online news; in other words, users who pay for entertainment on their devices are more likely to pay for information as well.

But for ailing newspapers, identifying and understanding the needs of which users are more likely to pay is only half the problem. What to offer them based on this knowledge is the other, and Goyanes makes a startling recommendation: "It is now time for online news organisations to develop new partnerships or strategic alliances with entertainment companies with the aim of creating and sharing new (complementary) services based on leisure, culture, entertainment, etc." To survive, "online news organisations need to go a step beyond the classical production of information when implementing paid content strategies."

Goyanes' research shows that younger readers should be foremost in these strategies: "Despite the constant decline of young readers in the traditional newspaper industry, the internet presents a great opportunity for media managers to attract and convince them, since it is the market segment that is more likely to pay for information."

This article is essential reading for anyone involved in either online or traditional news media, as it illustrates the on-going effects of the digital revolution on the creation, distribution and consumption of news.

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Story Source:

The above story is based on materials provided by Taylor & Francis. Note: Materials may be edited for content and length.

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Journal Reference:

1. Manuel Goyanes. An Empirical Study of Factors that Influence the Willingness to Pay for Online News. Journalism Practice, 2014; 1 DOI: 10.1080/17512786.2014.882056

Quantum mechanisms of organic devices for alternative solar panels are revealed

 

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Photos of the simulation of the evolution in the transfer of charge from the polymer to the fullerene in femtoseconds.

Silicon panel-based technology requires a very costly, contaminating manufacturing process, while organic photovoltaic (OPV) devices have been positioned as one of the most attractive alternatives as a source of solar energy.

This research has made a ground-breaking discovery because it is the first time that the quantum mechanisms that trigger the photovoltaic function of these devices have been deciphered. Angel Rubio, Professor of Condensed Matter Physics at the Faculty of Chemistry of the UPV/EHU-University of the Basque Country, director of the Nano-Bio Spectroscopy Group, and associate researcher of the Donostia International Physics Center (DIPC), has participated in the research conducted in this field in collaboration with various centres in Germany, Italy and France.

These organic devices use a photosensitive polymer linked to a carbon nanostructure that functions as a current collector. When light falls on the device, the polymer traps the particles of light and induces the ultrafast transmission of electrons to the nanostructure through an electron impulse in the order of femtoseconds (fs), in other words, 10-15 seconds. Evidence was recently found to confirm this ultrafast transfer, but the research of Rubio and his team has gone a step further because it has succeeded in deciphering the element mechanism that unleashes the electron transfer between the polymer and the nanostructure. The first-principal simulations in a simplified model predicted that the coherent vibrations are the ones that dictate the periodic transfer of charge between the polymer and the fullerene.

The group involved in the experiment confirmed this prediction by studying the optical response of a common material comprising a polymer and a by-product of the fullerene (a conventional nanostructure with a spherical shape) by means of high-resolution temporal spectroscopy.

The results confirmed that the coupling of the vibrations of the polymer and the fullerene bring about the electron transfer in a coherent and ultrafast way (≈23 fs), without any need to accept incoherent processes that are manifested in slower transfers (100 fs). These studies demonstrate the critical role played by quantum coherence in organic photovoltaic devices.

The research, due to be published this week in the journal Science, offers a vision that is consistent with element quantum processes in organic photovoltaic devices and constitutes a significant step forward in this field. "This research opens up the means for a substantial and controlled improvement in organic devices for photovoltaic applications," pointed out Prof Ángel Rubio.

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Story Source:

The above story is based on materials provided by University of the Basque Country. Note: Materials may be edited for content and length.

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Journal Reference:

1. S. M. Falke, C. A. Rozzi, D. Brida, M. Maiuri, M. Amato, E. Sommer, A. De Sio, A. Rubio, G. Cerullo, E. Molinari, C. Lienau. Coherent ultrafast charge transfer in an organic photovoltaic blend. Science, 2014; 344 (6187): 1001 DOI: 10.1126/science.1249771

X-ray pulses on demand from electron storage rings

 

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Some contemporary Synchroton Radiation methods need light pulsed x-rays with a specific time structure. HZB-users at BESSY II can use them now on demand. Graphics: Highway at night.

Everything we know nowadays about novel materials and the underlying processes in them we also know thanks to studies at contemporary synchrotron facilities like BESSY II. Here, relativistic electrons in a storage ring are employed to generate very brilliant and partly coherent light pulses from the THz to the X-ray regime in undulators and other devices. However, most of the techniques used at synchrotrons are very "photon hungry" and demand brighter and brighter light pulses to conduct innovative experiments. The general greed for stronger light pulses does, however, not really meet the requirements of one of the most important techniques in material science: photoelectron spectroscopy. Physicists and chemists have been using it for decades to study molecules, gases and surfaces of solids. However, if too many photons hit a surface at the same time, space charge effects deteriorate the results. Owing to these limits, certain material parameters stay hidden in such cases. Thus, a tailored temporal pattern of x-ray pulses is mandatory to move things forward in surface physics at Synchrotrons.

Scientists from HZB's Institute for Methods and Instrumentation in Synchrotron Radiation Research and the Accelerator Department have now jointly solved the gordic knot as they published in the journal Nature Communications. Their novel method is capable of picking single pulses out of a conventional pulse train as usually emitted from Synchrotron facilities. They managed to apply this for the first time to time-of-flight electron spectroscopy based on modern instruments as developed within a joint Lab with Uppsala University, Sweden.

Picking single pulses out of a pulse train

The pulse picking technique is based on a quasi resonant magnetic excitation of transverse oscillations in one specific relativistic electron bunch that -- like all others -- generates a radiation cone within an undulator. The selective excitation leads to an enlargement of the radiation cone. Employing a detour ("bump") in the electron beam path, the regular radiation and the radiation from the excited electrons can be easily separated and only pulses from the latter arrive -- once per revolution -- at the experiment. Thus, the arrival time of the pulses is now perfectly accommodated for modern high resolution time-of-flight spectrometers.

Users will be able to examine band structures with higher precision

"The development of the Pulse Picking by Resonant Excitation (PPRE) was science driven by our user community working with single bunch techniques. They demand more beamtime to improve studies on e.g. graphene, topological insulators and other "hot topics" in material science like the current debates about high Tc-Superconductors, magnetic ordering phenomena and catalytic surface effects for energy storage. Moreover, with pulse picking techniques at hand, we are now well prepared for our future light source with variable pulse lengths: BESSY-VSR, where users will appreciate pulse selection on demand to readily switch from high brightness to ultrashort pulses according to their individual needs" says Karsten Holldack, corresponding author of the paper.

First tests successful

The researchers have proven the workability of their method with ARTOF-time-of-flight spectrometers at different undulators and beamlines as well as in BESSY II's regular user mode. "Here we could certainly benefit from long year experiences with emitc       tance manipulation," says Dr. P. Kuske acting as head of the accelerator part of the team. Thanks to accelerator developments in the past, we are capable of even picking ultrashort pulses out of the bunch trains in low-alpha operation, a special operation mode of BESSY II. At last, the users can, already right now, individually switch -- within minutes -- between high static flux and the single pulse without touching any settings at their instruments and the sample.

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Story Source:

The above story is based on materials provided by Helmholtz-Zentrum Berlin für Materialien und Energie. Note: Materials may be edited for content and length.

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Journal Reference:

1. K. Holldack, R. Ovsyannikov, P. Kuske, R. Müller, A. Schälicke, M. Scheer, M. Gorgoi, D. Kühn, T. Leitner, S. Svensson, N. Mårtensson, A. Föhlisch. Single bunch X-ray pulses on demand from a multi-bunch synchrotron radiation source. Nature Communications, 2014; 5 DOI: 10.1038/ncomms5010

Aircraft wings that change their shape in flight can help to protect the environment

 

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Aircraft wings that change their shape in flight can help to protect the environment. Simulation of a flex module.

A top priority for any airline is to conserve as much fuel as possible -- and this helps to protect the environment. The EU project SARISTU aims to reduce kerosene consumption by six percent, and integrating flexible landing devices into aircraft wings is one step towards that target. Researchers will be showcasing this concept alongside other prototypes at the ILA Berlin Air Show from May 20-25.

Airport congestion has reached staggering levels as some 2.2 billion people a year take to the skies for business or pleasure. As their numbers grow and more jets add to pollution in the atmosphere, the drawbacks to the popularity of flying become obvious. This has encouraged airlines, aircraft manufacturers and researchers to pull together to reduce airliners' kerosene consumption and contribute to protecting the environment. One effort in this direction is the EU's SARISTU project, short for Smart Intelligent Aircraft Structures.

Landing flaps that change their shape

While birds are able to position their feathers to suit the airflow, aircraft wing components have so far only been rigid. As the name suggests, landing flaps at the trailing edge of the wing are extended for landing. This flap, too, is rigid, its movement being limited to rotation around an axis. This is set to change in the SARISTU project. "Landing flaps should one day be able to adjust to the air flow and so enhance the aerodynamics of the aircraft," explains Martin Schüller, researcher at the Fraunhofer Institute for Electronic Nano Systems ENAS in Chemnitz. A mechanism that alters the landing flap's shape to dynamically accommodate the airflow has already been developed by the consortium partners. Algorithms to control the required shape modifications in flight were programmed by ENAS, in collaboration with colleagues from the Italian Aerospace Research Center (CIRA) and the University of Naples.

The mechanism that allows the landing flap to change shape can only function if the skin of the landing flap can be stretched as it moves, a problem tackled by researchers from the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Bremen. "We've come up with a silicon skin with alternate rigid and soft zones," reveals Andreas Lühring from Fraunhofer IFAM. "There are five hard and three soft zones, enclosed within a silicon skin cover extending over the top."

The mechanism sits underneath the soft zones, the areas that are most distended. While the novel design is noteworthy, it is the material itself that stands out, since the flexible parts are made of elastomeric foam that retain their elasticity even at temperatures ranging from minus 55 to 80 degrees Celsius.

Four 90-centimeter-long prototypes -- two of which feature skin segments -- are already undergoing testing. Does the mechanism work? Are the forces being transferred correctly? These are questions for upcoming tests in the wind tunnel. Scientists will be showcasing the prototype at the ILA Berlin Air Show from May 20 -- 25.

Maneuverable wingtips

A single improvement won't be enough to cut kerosene consumption by six percent. Since a variety of measures are needed, scientists from Fraunhofer IFAM are participating in a second subproject focusing on the wingtip. Here the SARISTU consortium has developed a tab that forms part of the wing tip and changes shape during flight to keep air resistance as low as possible. Any gap between the flap and the fixed aircraft wing would cancel out any positive effect. "This led us to develop an elastic connecting element, and this work already covers everything from the chemical makeup to the process technology and manufacture of the component," says Lühring. Like the landing tab, this component retains its elasticity at temperatures ranging from minus 55 to 80 degrees Celsius, and it easily copes with the high wind speeds involved. Researchers will be showcasing the prototype at the ILA Berlin Air Show.

Funding

This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 284562.

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Story Source:

The above story is based on materials provided by Fraunhofer-Gesellschaft. Note: Materials may be edited for content and length.

Researchers design a new structure that absorbs all sound

 

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V. J. Sánchez-Morcillo with materials.

A new step toward the perfect acoustic absorber. Researchers of the Universitat Politècnica de València at the Campus de Gandia have designed and experimentally evaluated in the laboratory a new structure made of conventional porous materials -- used in the construction industry -- that permit the complete absorption of sound at a wide range of frequencies.

The Technical University of Denmark, the LUNAM Université of Le Mans (France) and the Institute of Photonic Sciences (ICFO, in Spanish) have also taken part in this project. The results have been released in Scientific Reports, from Nature Publishing.

"Our study tackles one of the most important problems of society today from a new point of view: the design of materials and surfaces able to significantly reduce noise. In view of the results, we believe we have taken an important step toward the perfect absorber. And that has been done just by reconfiguring a known material," says Víctor Sánchez-Morcillo, researcher at the Campus de Gandia of the Universitat Politècnica de València and director of the Master's Degree in Acoustic Engineering, taught at this campus.

In their work, the researchers have demonstrated how the designed structure achieves extraordinary sound absorption using an apparently contradictory strategy: the sound attenuation increases when the quantity of absorbent material is reduced. This way, a totally reflective surface becomes a perfect absorbent despite the fact that, for the most part, there is no material that absorbs sound.

The key to understanding this reaction is the following: the new configuration of the material, in periodically distributed panels, allows sound waves to easily enter the material and increases the interaction between it -the wave- and the structure, thereby increasing the absorption.

As for its possible applications, Víctor Sánchez says that the study's conclusions open a new way to design new noise reduction solutions such as the development of new baffles to reduce noise pollution caused by roads, railways, etc.

All the experimental development of this work has been done at the Campus de Gandia of the Universitat Politècnica de València, a center with a wide research and teaching experience related to acoustics.

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Story Source:

The above story is based on materials provided by Asociación RUVID. Note: Materials may be edited for content and length.

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Journal Reference:

1. J. Christensen, V. Romero-García, R. Picó, A. Cebrecos, F. J. García de Abajo, N. A. Mortensen, M. Willatzen, V. J. Sánchez-Morcillo. Extraordinary absorption of sound in porous lamella-crystals. Scientific Reports, 2014; 4 DOI: 10.1038/srep04674