Posts belonging to Category green power



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/
A
ND
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/

New Efficiency Record with Dual-Junction Solar Cell

Scientists at the Energy Department’s National Renewable Energy Laboratory (NREL) and at the Swiss Center for Electronics and Microtechnology (CSEM) have jointly set a new world record for converting non-concentrated (1-sun) sunlight into electricity using a dual-junction III-V/Si solar cellThe newly certified record conversion efficiency of 29.8 percent was set using a top cell made of gallium indium phosphide developed by NREL, and a bottom cell made of crystalline silicon developed by CSEM using silicon heterojunction technology. The two cells were made separately and then stacked by NREL.

dual junctio solar cell

It’s a record within this mechanically stacked category,” said David Young, a senior researcher at NREL. “The performance of the dual-junction device exceeded the theoretical limit of 29.4 percent for crystalline silicon solar cells.”

Young is co-author of a paper, “Realization of GaInP/Si dual-junction solar cells with 29.8 percent one-sun efficiency,” which details the steps taken to break the previous record. His co-authors from NREL are Stephanie Essig, Myles Steiner, John Geisz, Scott Ward, Tom Moriarty, Vincenzo LaSalvia, and Pauls Stradins. The paper has been submitted for publication in the IEEE Journal of Photovoltaics.

Essig attracted interest from CSEM when she presented a paper, “Progress Towards a 30 percent Efficient GaInP/Si Tandem Solar Cell,” to the 5th International Conference on Silicon Photovoltaics, in Germany in March. “We believe that the silicon heterojunction technology is today the most efficient silicon technology for application in tandem solar cells” said Christophe Ballif, head of PV activities at CSEM.

CSEM partnered with the NREL scientists with the objective to demonstrate that 30 percent efficient tandem cells can be realized using silicon heterojunction bottom cells, thanks to the combination with high performance top cells such as those developed by NREL,” said Matthieu Despeisse, the manager of crystalline silicon activities at CSEM.

The record was published in “Solar cell efficiency tables.”

Source: http://www.nrel.gov/

Tesla’s Competitor Faraday Future Presents Its Electric Car

A car firm hoping to disrupt the auto industry has shown off its first concept vehicle at the CES tech show (Las Vegas). Faraday Future said its battery-powered FFZero1 would project information over the driver’s view and include a smartphone dock in its steering wheel. The firm highlighted, however, that the modular basis of its design meant it could easily reconfigure the elements to create other types of electric vehicles including pick-up trucks.
The company – which is backed by the Chinese internet TV provider LeTV – said it was on course to deliver its first production vehicle in two years’ time. Its research chief Nick Sampson – who was formerly an engineer at rival electric car-maker Tesla – suggested his firm was able to move faster than others thanks to its adoption of “variable production architecture“. He explained this meant it would use the same basic underlying structure on all its vehicles, adapting it to include anywhere from one to four motors, battery packs of various sizes, different types of wheelbases and other optional parts.

faraday future electric car

The internet-connected 1,000-horsepower FFZero1 incorporates several ambitious elements including:
– The ability to top 200mph (321 kph) and accelerate from zero to 60mph in less than three seconds
– A helmet that provides oxygen and water to the driver
– “Aero tunnels” that channel air through the vehicle to reduce drag and cool the batteries
– A multi-touch screen interface and augmented reality views projected onto the road ahead

The car’s obviously very radical but that’s what concepts are all about,” commented Thilo Koslowski from the tech consultancy Gartner. “I think Faraday has a good understanding of what it has to do in order to be successful. But we will have to see if it will be successful. I can tell you that the established vehicle manufacturers are not standing still either.

Scott Evans, associate editor at the Motor Trend news site, was more doubtful: “Faraday Future claims to be disrupting the industry and completely rethinking the car, but is promising stuff everyone else is doing,” he tweeted.
Source: http://www.bbc.com/