Posts belonging to Category green power



Electric Cars That Eat CO2

An interdisciplinary team of scientists has worked out a way to make electric vehicles that only are not only carbon neutral but carbon negative, capable of actually reducing the amount of atmospheric carbon dioxide as they operate.

They have done so by demonstrating how the graphite electrodes used in the lithium-ion batteries that power electric automobiles can be replaced with carbon material recovered from the atmosphere. The unusual pairing of carbon dioxide conversion and advanced battery technology is the result of a collaboration between the laboratory of Assistant Professor of Mechanical Engineering Cary Pint at Vanderbilt University and Professor of Chemistry Stuart Licht at George Washington University. The team adapted a solar-powered process that converts carbon dioxide into carbon so that it produces carbon nanotubes and demonstrated that the nanotubes can be incorporated into both lithium-ion batteries like those used in electric vehicles and electronic devices and low-cost sodium-ion batteries under development for large-scale applications, such as the electric grid.

Tesla Model 3

This approach not only produces better batteries but it also establishes a value for carbon dioxide recovered from the atmosphere that is associated with the end-user battery cost unlike most efforts to reuse CO2 that are aimed at low-valued fuels, like methanol, that cannot justify the cost required to produce them,” said Pint. “Our climate-change solution is two fold: (1) to transform the greenhouse gas carbon dioxide into valuable products and (2) to provide greenhouse gas emission-free alternatives to today’s industrial and transportation fossil fuel processes,” adds Licht. “In addition to better batteries other applications for the carbon nanotubes include carbon composites for strong, lightweight construction materials, sports equipment and car, truck and airplane bodies.

The project builds upon a solar thermal electrochemical process (STEP) that can create carbon nanofibers from ambient carbon dioxide developed by the Licht group and described in the journal Nano Letters last August. STEP uses solar energy to provide both the electrical and thermal energy necessary to break down carbon dioxide into carbon and oxygen and to produce carbon nanotubes that are stable, flexible, conductive and stronger than steel.

The recipe for converting carbon dioxide gas into batteries is described in the paper titled “Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes” published online on Mar. 2 by the journal ACS Central Science.

Source: http://news.vanderbilt.edu/

New Efficient Materials For Solar Fuel Cells

University of Texas at Arlington (UTA) chemists have developed new high-performing materials for cells that harness sunlight to split carbon dioxide and water into useable fuels like methanol and hydrogen gas. These “green fuels” can be used to power cars, home appliances or even to store energy in batteries.

solar fuel cells

Technologies that simultaneously permit us to remove greenhouse gases like carbon dioxide while harnessing and storing the energy of sunlight as fuel are at the forefront of current research,” said Krishnan Rajeshwar, UTA distinguished professor of chemistry and biochemistry and co-founder of the University’s Center of Renewable Energy, Science and Technology. “Our new material could improve the safety, efficiency and cost-effectiveness of solar fuel generation, which is not yet economically viable,” he added.

The new hybrid platform uses ultra-long carbon nanotube networks with a homogeneous coating of copper oxide nanocrystals. It demonstrates both the high electrical conductivity of carbon nanotubes and the photocathode qualities of copper oxide, efficiently converting light into the photocurrents needed for the photoelectrochemical reduction process. Morteza Khaledi, dean of the UTA College of Science, said Rajeshwar’s work is representative of the University’s commitment to addressing critical issues with global environmental impact under the Strategic Plan 2020.

Source: https://www.uta.edu/

Compact, Ultra Sensitive BioSensor Gives Infos From A Blood Drop

Imagine a hand-held environmental sensor that can instantly test water for lead, E. coli, and pesticides all at the same time, or a biosensor that can perform a complete blood workup from just a single drop. That’s the promise of nanoscale plasmonic interferometry, a technique that combines nanotechnology with plasmonics—the interaction between electrons in a metal and light.

Now researchers from Brown University’s School of Engineering have made an important fundamental advance that could make such devices more practical. The research team has developed a technique that eliminates the need for highly specialized external light sources that deliver coherent light, which the technique normally requires. The advance could enable more versatile and more compact devices.

  • FluorescencePlasmonicInterferometryPlasmonic interferometers that have light emitters within them could make for better, more compact biosensors.

It has always been assumed that coherent light was necessary for plasmonic interferometry,” said Domenico Pacifici, a professor of engineering who oversaw the work with his postdoctoral researcher Dongfang Li, and graduate student Jing Feng. “But we were able to disprove that assumption.”

The research is described in Nature Scientific Reports.

Source: https://news.brown.edu/

Color Printer Uses A Colorless Ink

From dot-matrix to 3-D, printing technology has come a long way in 40 years. But all of these technologies have created hues by using dye inks, which can be taxing on the environment. Now a team reports in ACS Nano the development of a colorless, non-toxic ink for use in inkjet printers. Instead of relying on dyes, the team exploits the nanostructure of this ink to create color on a page with inkjet printing.

squirrelThis image of a squirrel was printed in color by controlling the thickness of a colorless ink deposited on a thin film

Current technologies blend dyes — think CMYK or RGB — to print in color. But these substances can harm the environment. Aleksandr V. Yakovlev, Alexandr V. Vinogradov and colleagues at ITMO University (Russia) wanted to develop a nanostructure color printing technology that is “greener” and can be printed on a wide variety of surfaces.

The team found that a colorless titanium dioxide-based colloidal ink was the best suited for the job. It does not require high temperature fixing and can be deposited on many surfaces. The researchers can control the color produced on surfaces by varying the thickness of ink deposition from a normal inkjet printer. Creating a vibrant color red with this method and this very narrow angle of coloring remains a challenge. This method, however, has generated the first reported “green” ink that is both safe for the ecosystem and does not fade from UV exposure, the researchers say.

Source: http://www.acs.org/

Very Efficient Nanowires Store Solar Energy

California is committed to 33 percent energy from renewable resources by 2020. With that deadline fast approaching, researchers across the state are busy exploring options. Solar energy is attractive but for widespread adoption, it requires transformation into a storable form. This week in ACS Central Science, researchers report that nanowires made from multiple metal oxides could put solar ahead in this race. One way to harness solar power for broader use is through photoelectrochemical (PEC) water splitting that provides hydrogen for fuel cells. Many materials that can perform the reaction exist, but most of these candidates suffer from issues, ranging from efficiency to stability and cost. Peidong Yang from Berkeley University of California  and colleagues designed a system where nanowires from one of the most commonly used materials (TiO2) acts as a “host” for “guestnanoparticles from another oxide called BiVO4.

nanowires splitting waterTIO2 NANOWIRES ACT AS HOSTS FOR BIVO4 GUESTS IN A WATER-SPLITTING REACTION

BiVO4 is a newly introduced material that is among the best ones for absorbing light and performing the water splitting reaction, but does not carry charge well while TiO2 is stable, cheap and an efficient charge carrier but does not absorb light well. Together with a unique studded nanowire architecture, the new system works better than either material alone. The authors state their approach can be used to improve the efficiencies of other photoconversion materials.

Source: http://www.eurekalert.org/
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http://nanowires.berkeley.edu/

China: A Cheap And Frugal Electric Car

Renault-Nissan will develop an affordable electric car for China because the alliance’s current offering, the Nissan Leaf, is too expensive for the local market. Nissan sold just 1,273 units of the Venucia e30, a local version of the Leaf, in China last year, according to the China Association of Automobile Manufacturers (CAAM). The car starts at 242,800 yuan ($36,900).

Venucia-Viwa-500x283I am unhappy with Venucia sales. We envisaged much more than that. We know price is a handicap,” said Carlos Ghosn, Chief Excecutive Officer of Renault-Nissan. “For me the solution will be a very cheap electric car,” Ghosn told journalists at the opening of Renault’s plant here in central China.. Ghosn did not comment on possible sales in markets outside China such as Europe or the size of the car.

China’s market for cars termed ‘new energy vehicles‘ — pure EVs and plug-in hybrids — has rapidly expanded in the last few years to reach 379,000 in 2015, according to government figures quoted by the China Daily newspaper. Ghosn said that despite the incentives, most sales were very cheap electric vehicles made by local brands costing between 30,00050,000 yuan ($4,600$7,000). The biggest selling electric car last year was the tiny Kandi EV city car with 16,736 sold, according to CAAM.

The government is saying we want more electric cars. The public is saying ‘yes, but we want them cheap‘, Ghosn said. He added Renault-Nissan would start development of an affordable electric car but the automakers first had to define what the public would accept. “We need to work out what are the best compromises between acceptable performance and lowest price possible“.

Source: http://europe.autonews.com/

Electric Car: Will the Next Tesla Sell for $25,000?

Tesla Motors Inc. was built with one overriding objective: to bring electric cars to the masses. After more than a decade of work, Tesla Chief Executive Officer Elon Musk believes it’s just about time. The company is set to begin taking pre-orders on its$35,000 Model 3 next month—and by $35,000, Tesla really means as little as $25,000Tesla has confirmed that the $35,000 price tag on the Model 3 doesn’t include the significant federal and state incentives available to electric car buyers. Official confirmation from the company echoes what Musk told reporters at an auto show more than a year ago: “When I say $35,000, I’m talking about without any credits.

The distinction Tesla is making here between the price before and after tax subsidies is crucial; these tax incentives can knock off as much as $10,000 from the cost of purchase, drastically increasing the size of the market for the Model 3. The pre-subsidy price was increasingly in doubt after the company set the starting price of its Model X luxury SUV at $80,000, more than analysts initially expected1.

Tesla Model 3
We can confirm it’s $35,000 before incentives,” a Tesla spokeswoman, Khobi Brooklyn, told Bloomberg.
We haven’t changed our minds.

To understand why pricing is so important, just look at what Americans are currently willing to spend. The average new car costs about $31,000, according to an analysis by Salim Morsy of Bloomberg New Energy Finance. Almost all the mass-market vehicles sold above that price threshold are SUVs and trucks. There’s only one car comparable in size to the Model 3 that amasses more than 100,000 in annual sales with a $35,000 price tag: the BMW 3 Series.

Another crucial figure: the range. Tesla announces 250 miles. At 25,000 dollars, the Tesla Model 3 is definitively competitive.

Source: http://www.bloomberg.com/

How To Store 10 Times More Energy In A Li-ion Battery

Scientists have been trying for years to make a practical lithium-ion battery anode out of silicon, which could store 10 times more energy per charge than today’s commercial anodes and make high-performance batteries a lot smaller and lighter. But two major problems have stood in the way: Silicon particles swell, crack and shatter during battery charging, and they react with the battery electrolyte to form a coating that saps their performance. Now, a team from Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory has come up with a possible solution: Wrap each and every silicon anode particle in a custom-fit cage made of graphene, a pure form of carbon that is the thinnest and strongest material known and a great conductor of electricity.

In a report published Jan. 25 in Nature Energy, they describe a simple, three-step method for building microscopic graphene cages of just the right size: roomy enough to let the silicon particle expand as the battery charges, yet tight enough to hold all the pieces together when the particle falls apart, so it can continue to function at high capacity. The strong, flexible cages also block destructive chemical reactions with the electrolyte.

graphene_cageThis time-lapse movie from an electron microscope shows the new battery material in action: a silicon particle expanding and cracking inside a graphene cage while being charged. The cage holds the pieces of the particle together and preserves its electrical conductivity and performance

In testing, the graphene cages actually enhanced the electrical conductivity of the particles and provided high charge capacity, chemical stability and efficiency,” said Yi Cui, an associate professor at SLAC and Stanford who led the research. “The method can be applied to other electrode materials, too, making energy-dense, low-cost battery materials a realistic possibility.

This new method allows us to use much larger silicon particles that are one to three microns, or millionths of a meter, in diameter, which are cheap and widely available,” Cui adds. “In fact, the particles we used are very similar to the waste created by milling silicon ingots to make semiconductor chips; they’re like bits of sawdust of all shapes and sizes. Particles this big have never performed well in battery anodes before, so this is a very exciting new achievement, and we think it offers a practical solution.

Source: https://www6.slac.stanford.edu/

Smart Windows Clean Themselves, Save Energy

A revolutionary new type of smart window could cut window-cleaning costs in tall buildings while reducing heating bills and boosting worker productivity. Developed by University College London (UCL) with support from EPSRC, prototype samples confirm that the glass can deliver three key benefits:
Self-cleaning: The window is ultra-resistant to water, so rain hitting the outside forms spherical droplets that roll easily over the surface – picking up dirt, dust and other contaminants and carrying them away. This is due to the pencil-like, conical design of nanostructures engraved onto the glass, trapping air and ensuring only a tiny amount of water comes into contact with the surface.
 Energy-saving: The glass is coated with a very thin (5-10nm) film of window-cleaning of vanadium dioxide which during cold periods stops thermal radiation escaping and so prevents heat loss; during hot periods it prevents infrared radiation from the sun entering the building.
 Anti-glare: The design of the nanostructures also gives the windows the same anti-reflective properties found in the eyes of moths and other creatures that have evolved to hide from predators.

self cleaning windowA scanning electron miscroscope photograph shows the pyramid-like nanostructures engraved onto glass: at 200nm they are 100 times smaller than a human hair. Controlling the surface morphology at the nanoscale allows scientists to tailor how the glass interacts with liquids and light with high precision

This is the first time that a nanostructure has been combined with a thermochromic coating. The bio-inspired nanostructure amplifies the thermochromics properties of the coating and the net result is a self-cleaning, highly performing smart window, said Dr Ioannis Papakonstantinou of UCL. The UCL team calculate that the windows could result in a reduction in heating bills of up to 40 per cent.

Source: https://www.epsrc.ac.uk/

Efficient Triboelectric Generator Embedded In A Shoe

A two-stage power management and storage system could dramatically improve the efficiency of triboelectric generators that harvest energy from irregular human motion such as walking, running or finger tapping. The system uses a small capacitor to capture alternating current generated by the biomechanical activity. When the first capacitor fills, a power management circuit then feeds the electricity into a battery or larger capacitor. This second storage device supplies DC current at voltages appropriate for powering wearable and mobile devices such as watches, heart monitors, calculators, thermometers – and even wireless remote entry devices for vehicles. By matching the impedance of the storage device to that of the triboelectric generators, the new system can boost energy efficiency from just one percent to as much as 60 percent.

Triboelectric shoes

llustration shows how a triboelectric generator embedded in a shoe would produce electricity as a person walked

With a high-output triboelectric generator and this power management circuit, we can power a range of applications from human motion,” said Simiao Niu, a graduate research assistant in the School of Materials Science and Engineering at the Georgia Institute of Technology. “The first stage of our system is matched to the triboelectric nanogenerator, and the second stage is matched to the application that it will be powering.

The research has been reported in the journal Nature Communications.

Source: http://www.news.gatech.edu/

Your Own Farm Indoors

Growing your own produce just got really easy. This is a farm cube – a fully enclosed ecosystem capable of growing hydroponic vegetables indoors.

growing vegetables indoorsCLICK ON THE IMAGE TO ENJOY THE VIDEO
In this one (Farm Cube), the one cycle, around six weeks, 200 pieces or 100 pieces depending on different vegetable”, says Jack Ting, CEO of the company Opcom (Taiwan). Seedlings are loaded into the cube. The growth cycle is then completely automated using farming software that monitors the plants and adjusts the environment accordingly, adding the perfect amount of air, light, and water needed for different stages of development. Not home and worried about your farm cube? There’s an App for that. Cameras and sensors allow you to monitor everything from the PH levels to the LED light settings from anywhere with an Internet connection. Its makers boast that the veg produced in their cubes are better for you than anything you can pick up at the market.

All water is UV light purified so it is very safe, even our vegetables, no need to wash“, adds Jack Ting. The company also makes the Farm Container. This solar powered multi-cube system can grow 2,000 plants at once…enough lettuce to feed an army of vegetarians with big appetites.

Source: http://www.reuters.com/

Battery Shuts Down When Overheating, Then Restarts

Stanford researchers have developed the first lithium-ion battery that shuts down before overheating, then restarts immediately when the temperature cools. The new technology could prevent the kind of fires that have prompted recalls and bans on a wide range of battery-powered devices, from recliners and computers to navigation systems and hoverboards.

hoverboard

People have tried different strategies to solve the problem of accidental fires in lithium-ion batteries,” said Zhenan Bao, a professor of chemical engineering at Stanford. “We’ve designed the first battery that can be shut down and revived over repeated heating and cooling cycles without compromising performance.

Several techniques have been used to prevent battery fires, such as adding flame retardants to the electrolyte. In 2014, Stanford engineer Yi Cui created a “smart” battery that provides ample warning before it gets too hot. “Unfortunately, these techniques are irreversible, so the battery is no longer functional after it overheats,” said study co-author Cui, an associate professor of materials science and engineering and of photon science. “Clearly, in spite of the many efforts made thus far, battery safety remains an important concern and requires a new approach.”

Bao and her colleagues describe the new battery in a study published in the Jan. 11 issue of the new journal Nature Energy.

Source: http://news.stanford.edu/