Posts belonging to Category green power



Japan Bets On Hydrogen As A Green Energy Source

Hydrogen gas is a promising alternative energy source to overcome our reliance on carbon-based fuels, and has the benefit of producing only water when it is reacted with oxygen. However, hydrogen is highly reactive and flammable, so it requires careful handling and storage. Typical hydrogen storage materials are limited by factors like water sensitivity, risk of explosion, difficulty of control of hydrogen-generation.

alstom-hydrogen-electric-train Hydrogen gas can be produced efficiently from organosilanes, some of which are suitably air-stable, non-toxic, and cheap. Catalysts that can efficiently produce hydrogen from organosilanes are therefore desired with the ultimate goal of realizing safe, inexpensive hydrogen production in high yield. Ideally, the catalyst should also operate at room temperature under aerobic conditions without the need for additional energy input. A research team led by Kiyotomi Kaneda and Takato Mitsudome at Osaka University have now developed a catalyst that realizes efficient environmentally friendly hydrogen production from organosilanes. The catalyst is composed of gold nanoparticles with a diameter of around 2 nm supported on hydroxyapatite.

The team then added the nanoparticle catalyst to solutions of different organosilanes to measure its ability to induce hydrogen production. The nanoparticle catalyst displayed the highest turnover frequency and number attained to date for hydrogen production catalysts from organosilanes. For example, the  converted 99% of dimethylphenylsilane to the corresponding silanol in just 9 min at room temperature, releasing an equimolar amount of hydrogen gas at the same time. Importantly, the catalyst was recyclable without loss of activity. On/off switching of hydrogen production was achieved using the nanoparticle catalyst because it could be easily separated from its organosilane substrate by filtration. The activity of the catalyst increased as the nanoparticle size decreased.

A prototype portable hydrogen fuel cell containing the nanoparticle catalyst and an organosilane substrate was fabricated. The fuel cell generated power in air at room temperature and could be switched on and off as desired.

Generation of hydrogen from inexpensive organosilane substrates under ambient conditions without additional energy input represents an exciting advance towards the goal of using hydrogen as a green energy source.

Source: https://www.eurekalert.org/
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http://www.nature.com/

Why North Atlantic Tuna Is Less Toxic ?

In a piece of welcome news for seafood lovers, a Stony Brook-led research team has found declining levels of mercury in bluefin tuna caught in the North Atlantic over the past decadeMercury is a neurotoxin harmful to humans, and tuna provide more mercury to humans than any other source.

A study led by Stony Brook University’s School of Marine and Atmospheric Sciences (SoMAS) and published in Environmental Science & Technology provides a new data set, the largest of its kind, of mercury concentrations in Atlantic bluefin tuna. The data demonstrate that, while tissue concentrations were higher than in most other fish species, there has been a consistent decline in mercury concentrations in these tuna over time, regardless of age of the fish.

blue-sea

KEY FINDINGS:

The researchers measured mercury concentrations from the tissue of 1,292 bluefin tuna caught between 2004 and 2012

  • Over the eight-year period, mercury levels in the fish fell 19 percent.
  • Mercury concentrations were generally high, and were highest in the largest, oldest fish; no differences were noted between males and females.
  • Mercury in the air over the North Atlantic fell 20 percent from 2001 to 2009.
  • Global levels of mercury emissions have fallen 2.8 percent a year from 1990 to 2007.

The rate of decline parallels the declines – over the same time period — of mercury emissions, mercury levels in North Atlantic air, and mercury concentrations in North Atlantic seawater. Authors of the study include Stony Brook’s Cheng-Shiuan Lee, a Ph.D student in chemical/biological oceanography, and Nicholas S. Fisher, Distinguished Professor & Director, Consortium for Inter-Disciplinary Environmental Research at SoMAS.

According Fisher, the finding appears to indicate that changes in mercury levels in fish tissue respond in real time to changes in mercury loadings into the ocean. The study suggests that mercury levels may be improving as a result of declining coal use, reducing emissions that drift over the Atlantic.

Source: http://www.stonybrook.edu/

How To Capture Energy From Human Motion

The day of charging cellphones with finger swipes and powering Bluetooth headsets simply by walking is now much closer. Michigan State University engineering researchers have created a new way to harvest energy from human motion, using a film-like device that actually can be folded to create more power. With the low-cost device, known as a nanogenerator, the scientists successfully operated an LCD touch screen, a bank of 20 LED lights and a flexible keyboard, all with a simple touching or pressing motion and without the aid of a battery.

energy-from-human-motionThe foldable keyboard, created by Michigan State University engineer Nelson Sepulveda and his research team, operates by touch; no battery is needed. Sepulveda developed a new way to harvest energy from human motion using a pioneering device called a biocompatible ferroelectret nanogenerator, or FENG.

We’re on the path toward wearable devices powered by human motion,” said Nelson Sepulveda, associate professor of electrical and computer engineering and lead investigator of the project. “What I foresee, relatively soon, is the capability of not having to charge your cell phone for an entire week, for example, because that energy will be produced by your movement,” said Sepulveda,.

The innovative process starts with a silicone wafer, which is then fabricated with several layers, or thin sheets, of environmentally friendly substances including silver, polyimide and polypropylene ferroelectret. Ions are added so that each layer in the device contains charged particles. Electrical energy is created when the device is compressed by human motion, or mechanical energy. The completed device is called a biocompatible ferroelectret nanogenerator, or FENG. The device is as thin as a sheet of paper and can be adapted to many applications and sizes. The device used to power the LED lights was palm-sized, for example, while the device used to power the touch screen was as small as a finger.

Advantages such as being lightweight, flexible, biocompatible, scalable, low-cost and robust could make FENGa promising and alternative method in the field of mechanical-energy harvesting” for many autonomous electronics such as wireless headsets, cell phones and other touch-screen devices, the study says. Remarkably, the device also becomes more powerful when folded.

Each time you fold it you are increasing exponentially the amount of voltage you are creating,” Sepulveda said. “You can start with a large device, but when you fold it once, and again, and again, it’s now much smaller and has more energy. Now it may be small enough to put in a specially made heel of your shoe so it creates power each time your heel strikes the ground.” Sepulveda and his team are developing technology that would transmit the power generated from the heel strike to, say, a wireless headset.

The  findings have been published in the journal Nano Energy.

Nanoparticles Eradicate PreCancerous Cells In The Liver

According to the American Cancer Society, more than 700,000 new cases of liver cancer are diagnosed worldwide each year. Currently, the only cure for the disease is to surgically remove the cancerous part of the liver or transplant the entire organ. However, an international study led by University of Missouri (MU) – School of Medicine  researchers has proven that a new minimally invasive approach targets and destroys precancerous tumor cells in the livers of mice and invitro human cells.

liver cancer

The limitations when treating most forms of cancer involve collateral damage to healthy cells near tumor sites,” said Kattesh Katti, PhD, Curators’ Professor of Radiology and Physics at the MU School of Medicine and lead author of the study. “For more than a decade we have studied the use of nanotechnology to test whether targeted treatments would reduce or eliminate damage to nearby healthy cells. Of particular interest has been the use of green nanotechnology approaches pioneered here at MU that use natural chemical compounds from plants.”

The study was conducted in the United States and Egypt, and it involved the use of gold nanoparticles encapsulated by a protective stabilizer called gum Arabic. The nanoparticles were introduced to the livers of mice intravenously and were heated with a laser through a process known as photothermal therapy.

Gum Arabic is a natural gum made of the hardened sap from acacia trees,” said Katti, who also serves as director of the MU Institute of Green Nanotechnology and Professor of Medical Research at the MU School of Medicine. “It is FDA-approved for human consumption and is primarily used in the food industry as an additive. It also promotes adhesion of gold nanoparticles engineered to attract to precancerous and malignant cells – which are much more susceptible to lower levels of heat than healthy cells. Once the nanoparticles travel and adhere to cancerous cells, they are heated to a temperature that destroys them but leaves healthy tissue unaffected.”

Katti’s team studied a total of 224 mice. Half were identified as having precancerous cells in their livers. The other half had normal liver tissue. Outside of the control group, the mice received either an intravenous injection of gum Arabic alone or gum Arabic-encapsulated gold nanoparticles with or without laser therapy.

The administration of gum Arabic, gold nanoparticles and photothermal therapy caused no change to healthy tissue, which confirmed the safe use of these treatments,” Katti said. “However, the use of gum Arabic-encapsulated nanoparticles combined with photothermal therapy resulted in the targeted eradication of the precancerous cells and their genetic code in both our mice model and the human invitro cell model we developed for this study.”

Source: http://medicine.missouri.edu/

The Biggest Solar Plant Ever Built produces electricity at $0.10/kWh

The massive, 648-megawatt array was officially linked to the grid after being hooked up to a 400kV substation, the operator Adani Green Energy Ltd announced. The plant is spread across 2,500 acres in the town of Kamuthi in the Ramanathapuram district (India)  and will supply enough clean, green energy for 300,000 homes. The Deccan Chronicle reported that the $679 million solar park consists of 380,000 foundations, 2.5 million solar modules, 576 inverters, 154 transformers and 6,000-kilometers of cables. The plant was built with parts and machinery from around the world. Adani Group chairman Gautam Adani formally dedicated the structure to the nation.

solar-plant-in-india

“This is a momentous occasion for the state of Tamil Nadu as well as the entire country“, he said. “We are extremely happy to dedicate this plant to the nation; a plant of this magnitude reinstates the country’s ambitions of becoming one of the leading green energy producers in the world.”

India has an ambitious solar energy goal. In 2014, Indian Prime Minister Narendra Modi announced plans to increase solar power capacity to 100 gigawatts by 2022, five times higher than the previous target.

The plant was commissioned by Tamil Nadu chief minister J Jayalalithaa. Indian Express reported in July 2015 that the state government would buy the entire 648 megawatts produced by Adani at a fixed price of $0.10/kWh (Rs 7.01/kWh) for 25 years.

Source: http://www.ecowatch.com/

Diamond NanoThread, The New Wonder Material

Would you dress in diamond nanothreads? It’s not as far-fetched as you might think. And you’ll have a Brisbane-based carbon chemist and engineer to thank for it. QUT’s Dr Haifei Zhan is leading a global effort to work out how many ways humanity can use a newly-invented material with enormous potential – diamond nanothread (DNT). First created by Pennsylvania State University last year, one-dimensional DNT is similar to carbon nanotubes, hollow cylindrical tubes 10,000 times smaller than human hair, stronger than steel – but brittle.

diamond-nanothread

DNT, by comparison, is even thinner, incorporating kinks of hydrogen in the carbon’s hollow structure, called Stone-Wale (SW) transformation defects, which I’ve discovered reduces brittleness and adds flexibility,” said Dr Zhan, from QUT’s School of Chemistry, Physics and Mechanical Engineering.

That structure makes DNT a great candidate for a range of uses. It’s possible DNT may become as ubiquitous a plastic in the future, used in everything from clothing to cars.

DNT does not look like a rock diamond. Rather, its name refers to the way the carbon atoms are packed together, similar to diamond, giving it its phenomenal strength. Dr Zhan has been modelling the properties of DNT since it was invented, using large-scale molecular dynamics simulations and high-performance computing. He was the first to realise the SW defects were the key to DNT’s versatility.

While both carbon nanotubes and DNT have great potential, the more I model DNT properties, the more it looks to be a superior material,” Dr Zhan said. “The SW defects give DNT a flexibility that rigid carbon nanotubes can’t replicate – think of it as the difference between sewing with uncooked spaghetti and cooked spaghetti. “My simulations have shown that the SW defects act like hinges, connecting straight sections of DNT. And by changing the spacing of those defects, we can a change – or tune – the flexibility of the DNT.

That research is published in the peer-reviewed publication Nanoscale.

Source: https://www.qut.edu.au/

How To Store Hydrogen Fuel In Electric Cars

Layers of graphene separated by nanotube pillars of boron nitride may be a suitable material to store hydrogen fuel in cars, according to Rice University scientists. The Department of Energy has set benchmarks for storage materials that would make hydrogen a practical fuel for light-duty vehicles. The Rice lab of materials scientist Rouzbeh Shahsavari determined in a new computational study that pillared boron nitride and graphene could be a candidate.

hydrogenSimulations by Rice scientists show that pillared graphene boron nitride may be a suitable storage medium for hydrogen-powered vehicles. Above, the pink (boron) and blue (nitrogen) pillars serve as spacers for carbon graphene sheets (grey). The researchers showed the material worked best when doped with oxygen atoms (red), which enhanced its ability to adsorb and desorb hydrogen (white).

 

Just as pillars in a building make space between floors for people, pillars in boron nitride graphene make space for hydrogen atoms. The challenge is to make them enter and stay in sufficient numbers and exit upon demand.Shahsavari’s lab had already determined through computer models how tough and resilient pillared graphene structures would be, and later worked boron nitride nanotubes into the mix to model a unique three-dimensional architecture. (Samples of boron nitride nanotubes seamlessly bonded to graphene have been made.)

In their latest molecular dynamics simulations, the researchers found that either pillared graphene or pillared boron nitride graphene would offer abundant surface area (about 2,547 square meters per gram) with good recyclable properties under ambient conditions. Their models showed adding oxygen or lithium to the materials would make them even better at binding hydrogen. They focused the simulations on four variants: pillared structures of boron nitride or pillared boron nitride graphene doped with either oxygen or lithium. At room temperature and in ambient pressure, oxygen-doped boron nitride graphene proved the best, holding 11.6 percent of its weight in hydrogen (its gravimetric capacity) and about 60 grams per liter (its volumetric capacity); it easily beat competing technologies like porous boron nitride, metal oxide frameworks and carbon nanotubes.

The study by Shahsavari and Farzaneh Shayeganfar appears in the American Chemical Society journal Langmuir.

Source: http://news.rice.edu/

Solar Powered House: Tiles Instead Of Panels

Tesla founder and CEO Elon Musk wasn’t kidding when he said that the new Tesla solar roof product was better looking than an ordinary roof: the roofing replacement with solar energy gathering powers does indeed look great. It’s a far cry from the obvious and somewhat weird aftermarket panels you see applied to roofs after the fact today.

tesla-solar-tiles

The solar roofing comes in four distinct styles that Tesla presented at the event, including “Textured Glass Tile,” “Slate Glass Tile,” “Tuscan Glass Tile, and “Smooth Glass Tile.” Each of these achieves a different aesthetic look, but all resembled fairly closely a current roofing material style. Each is also transparent to solar, but appears opaque when viewed from an angle.

The current versions of the tiles actually have a two percent loss on efficiency, so 98 percent of what you’d normally get from a traditional solar panel, according to Elon Musk. But the company is working with 3M on improved coatings that have the potential to possibly go above normal efficiency, since it could trap the light within, leading to it bouncing around and resulting in less energy loss overall before it’s fully diffused.

Of course, there’s the matter of price: Tesla’s roof cost less than the full cost of a roof and electricity will be competitive or better than the cost of a traditional roof combined with the cost of electricity from the grid, Musk said. Tesla declined to provide specific pricing at the moment, since it will depend on a number of factor including installation specifics on a per home basis.

Standard roofing materials do not provide fiscal benefit back to the homeowner post-installation, besides improving the cost of the home. Tesla’s product does that, by generating enough energy to fully power a household, with the power designed to be stored in the new Powerwall 2.0 battery units so that homeowners can keep a reserve in case of excess need.

The solar roof product should start to see installations by summer next year, and Tesla plans to start with one or two of its four tile options, then gradually expand the options over time. As they’re made from quartz glass, they should last way longer than an asphalt tile — at least two or three times the longevity, though Musk later said “they should last longer than the house”.

Source: https://techcrunch.com/

Solar-powered Wireless Charging Station For Electric Bikes

Members of the Delft University of Technology (TU Delft) in Netherlands have presented the first solar-powered wireless charging station for electric bikes.

electric-station-for-electric-bikes

This is a major step forward in terms of sustainable transport and accelerating the energy transition because the combination of solar energy, wireless charging and electric bikes is unique. In this charging station, we charge the DC battery in the bike with the solar energy from the eight solar panels via the DC supply. The charging station can also store 10 kWh of solar energy in the batteries, enabling it to function independently“, sayd  Pavol Bauer, who leads the Direct Current (DC) Systems, Energy Conversion & Storage group at the University.

The charging station is ready for immediate use: it can accommodate four electric bikesan electric scooter and a research bike that are charged wirelessly. The charging station also serves as a living lab, a testbed for further research. In the last two years, ten students have graduated on the strength of their work on the project. For example, a student of Electrical Engineering, Mathematics and Computer Science designed a DC system and created a system to enable the bike to be charged wirelessly, another calculated and determined the output and position of the solar panels, and an Industrial Design Engineering student was responsible for designing the charging station.

The electric research bike is equipped with a dual stand and a small coil. At the charging station, the bike can be parked on the stand on a magnetic tile. The bike is charged directly via the coil. The user can monitor the charging status on a built-in screen on the charging station or on his or her mobile phone. Wireless charging takes around the same time as the ‘conventional‘ charging of electric bikes.

It is anticipated that the eight panels will generate sufficient energy to power the electric bikes and the scooter in winter. In summer, any excess power will be fed to the electricity grid. Pavol Bauer’s group now plans to work on the further development of wireless charging for various bikes and scooters. The ultimate aim is for the charging station to consist solely of several tiles used as a solar panel, which can be cycled on, known as solar roads. Integrating solar cells and the wireless charging system makes an expensive system unnecessary.

Source: http://www.tudelft.nl/

New Perovskite Solar Cell Outperforms Silicon Cells

Stanford and Oxford have created novel solar cells from crystalline perovskite that could outperform existing silicon cells on the market today. This design converts sunlight to electricity at efficiencies of 20 percent, similar to current technology but at much lower cost. Writing in the journal Science, researchers from Stanford and Oxford describe using tin and other abundant elements to create novel forms of perovskite – a photovoltaic crystalline material that’s thinner, more flexible and easier to manufacture than silicon crystals.

perovskite solar panelCLICK ON THE IMAGE TO ENJOY THE VIDEO

Perovskite semiconductors have shown great promise for making high-efficiency solar cells at low cost,” said study co-author Michael McGehee, a professor of materials science and engineering at Stanford. “We have designed a robust, all-perovskite device that converts sunlight into electricity with an efficiency of 20.3 percent, a rate comparable to silicon solar cells on the market today.”

The new device consists of two perovskite solar cells stacked in tandem. Each cell is printed on glass, but the same technology could be used to print the cells on plastic, McGehee added.

The all-perovskite tandem cells we have demonstrated clearly outline a roadmap for thin-film solar cells to deliver over 30 percent efficiency,” said co-author Henry Snaith, a professor of physics at Oxford. “This is just the beginning.”

Previous studies showed that adding a layer of perovskite can improve the efficiency of silicon solar cells. But a tandem device consisting of two all-perovskite cells would be cheaper and less energy-intensive to build, the authors said.

Source: http://news.stanford.edu/

Electric Car: Graphene Is The Next Revolution

Henrik Fisker, the famed automotive designer known for his work on iconic vehicles such as the Aston Martin DB9, the Aston Martin V8 Vantage and the BMW Z8, did not do well in an electric car venture that he launched in 2007. Fisker Automotive was a rival to Tesla Motors in the early days of the electric car industry, but it was not able to deliver its promised vehicles and had to declare bankruptcy in 2013. However, it seems that Fisker has not pushed electric cars out of his mind, as it was recently reported that he is returning to the electric vehicle scene with a new company named Fisker Inc. that will be taking form next year.

With rival Tesla Motors now the perceived leader in the industry, Fisker Inc. is looking to make a splash. It seems that the new company would be able to do so, as Fisker revealed that instead of the traditional lithium-ion batteries, Fisker Inc. vehicles will be powered by a new kind of battery known as graphene supercapacitors.

graphene-electric-car

It was earlier reported that the luxury electric car that Fisker Inc. is working on will have a full-charge range that will reach over 400 miles, which is significant because the longest range that Tesla Motors offers through its vehicles is 315 miles on the high-end version of the Model S. The 400-mile range is said to be made possible by the usage of graphene in electric car batteries, with the technology being referred to by Fisker as the “next big step” in the industry.

According to Michigan Technological University assistant professor Lucia Gauchia, graphene has a higher electron mobility and presents a higher active surface, which are characteristics that lead to faster charging times and expanded energy storage, respectively, when used for batteries.

Graphene, however, has so far been associated with high production costs. Fisker is looking to solve that problem and mass produce graphene through a machine that his battery division, named Fisker Nanotech, is looking to have patented. Through the machine, 1,000 kilograms of graphene can be produced at a cost of just 10 cents per gram.

Our battery technology is so much better than anything out there,” Fisker said, amid the many improvements that his company has made on the material’s application to electric car batteries.

Fisker also said that the first Fisker Inc. electric car is being planned to be unveiled in the second half of next year. The luxury electric vehicle will only have limited production, and will be in the price range of the higher-end models of the Model S. However, Fisker said that he will then be producing consumer-friendly electric vehicles that will be even cheaper compared with the Tesla Model 3 and the Chevrolet Bolt, following the footsteps of its rival.

Source: http://www.techtimes.com/

Perovskite Solar Cells One Step Closer To Mass Production

With the high environmental cost of conventional energy sources and the finite supply of fossil fuels, the importance of renewable energy sources has become much more apparent in recent years. However, efficiently harnessing solar energy for human use has been a difficult task. While silicon-based solar cells can be used to capture sunlight energy, they are costly to produce on an industrial scale. Research from the Energy Materials and Surface Sciences Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) in Japan, led by Prof. Yabing Qi, has focused on using organo-metal halide perovskite films in solar cells. These perovskite films are highly crystalline materials that can be formed by a large number of different chemical combinations and can be deposited at low cost. Recent publications from Prof. Qi’s lab cover three different areas of innovation in perovskite film research: a novel post annealing treatment to increase perovskite efficiency and stability, a discovery of the decomposition products of a specific perovskite, and a new means of producing perovskites that maintains solar efficiency when scaled up.

perovskite solar panel

In order to be useful as solar cells, perovskite films must be able to harvest solar energy at a high efficiency that is cost-effective, be relatively easy to manufacture, and be able to withstand the outdoor environment over a long period of time. Dr. Yan Jiang in Prof. Qi’s lab has recently published research in Materials Horizons that may help increase the solar efficiency of the organo-metal halide perovskite MAPbI3. He discovered that the use of a methylamine solution during post-annealing led to a decrease in problems associated with grain boundaries. Grain boundaries manifest as gaps between crystalline domains and can lead to unwanted charge recombination. This is a common occurrence in perovskite films and can reduce their efficiency, making the improvement of grain boundary issues essential to maintain high device performance. Dr. Jiang’s novel post annealing treatment produced solar cells that had fused grain boundaries, reduced charge recombination, and displayed an outstanding conversion efficiency of 18.4%. His treated perovskite films also exhibited exceptional stability and reproducibility, making his method useful for industrial production of solar cells.

 Source: https://www.oist.jp/