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Environmentally-Friendly Liquid Battery

A new liquid battery that is more environmentally friendly than its existing counterparts could help lead to safe, inexpensive storage of renewable energy for power grids, researchers in Shanghai say.

The new battery also has a much longer cycle life and much greater power than any current rechargeable battery, the scientists add.

The sun and wind are variable sources of power. As such, utility companies want massive rechargeable battery farms that can store the surplus energy from these renewable power sources for use when the sun goes down and the wind does not blow.

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Energous Readies Wireless Power Tech for Consumer Devices

Long range wireless power is one of the most exciting things we saw at CES this year. We've already talked about Ossia, and now, we're going to take a close look at Energous, whose WattUp technology we first saw at CES 2015. A few months ago, we spoke with Energous CTO Michael Leabman about the efficiency of his company’s system. Earlier this month, we spent over an hour in Energous' CES demo suite checking out demos, and speaking with Leabman about the future of wireless power and what the company has in store for 2016.

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Lithium-Ion Battery Warms Up, Operates In Subzero Temperatures

A new “all-climate” lithium-ion battery can rapidly heat itself to overcome freezing temperatures with little sacrifice in energy storage capacity and power, researchers say.

This advance might enable applications for which high-performance batteries are needed in extremely cold temperatures, such as electric cars in cold climates, high-altitude drones, and space exploration. EC Power is now creating all-climate battery cells in pilot-production volumes that can be put directly in vehicles, says study lead author Chao-Yang Wang, a mechanical and electrochemical engineer at Pennsylvania State University.

Lithium-ion batteries not only can suffer problems from overheating, but they also typically experience severe power loss at temperatures below zero degrees Celsius. The consequences of this weakness include slow charging in cold weather, limited regenerative braking, the need for larger, more expensive battery packs to start cold engines, and the reduction of vehicle cruise range by as much as 40 percent, researchers say.

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The Catalyst That Finally Gets Fuel Cell Vehicles on the Road?

One problem that has been plaguing the development of hydrogen-fueled vehicles is that hydrogen gas needs to be stored and transported in expensive pressurized tanks. Liquid energy carriers such as hydrogen dissolved in a salt solution are viewed as possible alternatives, but they’re also fraught with problems including the accumulation of byproducts. The simplest hydrogen carrier is water. But splitting hydrogen from oxygen requires, besides catalysts, a lot of energy. 

But now a research group called Team FAST, comprising students at the Technical University Eindhoven (TUE), in the Netherlands, thinks it has the hydrogen storage problem licked. To supply the one-meter-long scale model fuel cell vehicle they’ve developed with as much hydrogen as it needs, they’ve turned to formic acid (HCOOH). The liquid compound that can be created by joining carbon dioxide molecules with hydrogen with the help of catalysts and stored under atmospheric pressure. What’s more, catalysts can do the job of splitting formic acid into hydrogen and CO2—without an external energy source. 

Though this idea is not new, the efficiency of catalysts had been too low to deliver a stream of hydrogen sufficient to run fuel cells that could power a car. That is, until research completed last year by Georgy Filonenko, a recently-departed graduate student there, led to the discovery of a catalyst that is 10 times as efficient.

"The catalyst is a ruthenium complex which dissolves in the formic acid, and it is so active that you need only, what I call 'homeopathic' quantities, to dissociate the formic acid,” says Emiel Hensen, a chemist who supervised Filonenko's PhD research. Besides being required in small quantities, the ruthenium complex is, unlike other catalysts, not fouled by air or water, facilitating its use in a automotive applications, says Hensen.

To test out the advance, the FAST team set out, a year and a half ago, to build a working an one-meter scale model of a hydrogen car. It contains an off-the-shelf fuel cell and a catalytic reactor the size of a coffee mug, explains Pieter Ottink, who is the spokesperson for the team. Having shown off this proof-of-concept version, they say the next step is to power a full-scale model, hopefully by the end of this year. The team also reports that they have struck a deal with a company that will supply them with a hydrogen bus.   

“We are not yet sure about how we will design the big system; scaling up a chemical reaction like this is dependent on a lot of variables,” says Ottink.  However, they plan to proceed carefully. “It does not seem to be efficient to make one big reactor, so we will [likely equip the bus with] multiple small ones,” he says. But who knows? “This technology is in a very early stage," Ottink adds.   

A fortuitous coincidence will certainly make things easier, however. “The catalytic reaction is efficient at around 80 degrees C, so you should warm it up. We have the advantage that the fuel cell also produces heat, and this heat can be used to warm up the reactor,” says Ottink.

Unfortunately, the CO2 liberated during the catalytic reaction is released into the air. But if the formic acid can be produced in a sustainable way—by, say, drawing CO2 from the flues of fossil-fueled power plants—the process would be carbon neutral.

Fluttering Flag Generates Power From Wind

Just by flapping in the wind, a new energy-generating flag produces enough electricity to power small electronic devices. The flag converts mechanical energy into electricity using the effect behind static electricity. Floating high above the ground using balloons, it could harvest high-altitude winds to power weather and environmental monitoring sensors, as well as navigation systems.

Winds at high altitudes are faster and more consistent than those near the ground, but ground-based turbines are unable to reach those heights. Many groups are testing technologies such as floating turbines, kites, sails, and winged craft to harness these high-altitude winds.

“How about a little piece of fabric for wind power?” asks Zhong Lin Wang, a materials science and engineering professor at Georgia Tech, in Atlanta. The flag’s low cost and easy scalability could make it competitive with other airborne wind power technologies, he says.The details of the Georgia Tech team’s research appear in the journal ACS Nano.

The flag operates on the triboelectric effect. When the surfaces of two different materials touch and separate, electrons transfer from one to the other, building up opposite charges on the two surfaces. This can lead to a voltage that drives electric current.

Wang’s group has made several generators that scavenge energy from body movements and mechanical vibrations to produce electricity. In early 2015, the team reported a slinky-shaped generator and an energy-scavenging fabric that could power gadgets using human motion.

The flag is the researchers’ newest form of triboelectric generator. They made it by weaving together 1.5-centimeter-wide, 30-cm-long strips made from two kinds of fabric. The weft is a nickel-coated polyester textile belt and the warp is a polyimide plastic-coated copper film. All the nickel belts are connected using copper tape to form one electrode; all the copper belts are connected together as the other electrode. The flag, which weighs 15 grams, can be bent, folded and twisted. 

“The weave is loose and there is a few hairs’ distance between the two fabric strips,” Wang explains. So as the flag flutters in artificially generated wind, the two fabric units repeatedly touch and separate from each other, generating power.

At a wind speed of 22 meters per second, the flag produces a maximum of about 40 volts and 30 microamperes. Three flags connected in parallel could light up 16 commercial LEDs. As a demonstration, the researchers connected the flag’s output to a button cell battery that powered a humidity and temperature sensor node that transmits data wirelessly to a computer. This whole system was tethered to a meteorological balloon that hovered in an indoor laboratory where the researchers were able to vary temperature and humidity. 

Hydrogen Adds Longevity to Laptops, Phones, and Drones, But Is It Practical?

Back in August, when we wrote about Intelligent Energy’s prototype fuel cell iPhone, we weren’t totally convinced that it was an idea that would catch on. We’re still not totally convinced, but yesterday at the Consumer Electronics Show in Las Vegas, we stopped by Intelligent Energy’s suite to check out the prototype ourselves, along with a fuel cell-powered MacBook and a drone that can fly for up to two hours on a small canister of hydrogen gas.

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Stable Perovskite Cell Boosts Solar Power

By adding cesium to a kind of crystal known as a perovskite, researchers say they can create tandem solar cells that may be much better at converting light to electricity than conventional solar cells while also being far more stable than previous comparable tandem cells.

Photovoltaic cells based on silicon currently make up about 90 percent of the global photovoltaic market. However, the rate at which the power conversion efficiency of silicon photovoltaics has improved has slowed dramatically, growing only from 25 percent to 25.6 percent in the past 15 years.

In order to create more efficient solar cells while making the most of the existing industrial capacity for silicon photovoltaics, researchers would like to create so-called tandem solar cells that combine silicon with other materials. One set of potential partners for silicon in these cells are perovskites, which are inexpensive and easily produced in labs.

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A Renewable Supergrid in Russia

Russia and Central Asia could rely on an economically viable 100 percent renewable energy system—wind and solar—in 2030,  says a report commissioned by the Neo-Carbon Energy Research Project in Finland. (By economical they mean a price per kilowatt-hour slightly higher than € 0.045 but lower than the cost of energy produced by today’s solar plants.) It's highly doubtful that Russia will actually move to such an energy system, according to the report’s authors, but their simulation at least showed that it’s possible.

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Ossia's Cota Wireless Power Tech Promises to Enable the Internet of Everything

Over the past year or so, we've seen enough companies promising to deliver truly wireless power that we're almost, almost starting to believe in it. But there's an awful lot of hype, compounded by the fact that there are a bunch of very different technologies all targeting the same goal: charging everything, everywhere, without plugs or cables or pads. Recently, we've taken a closer look at a few of these technologies, including uBeam's ultrasonic power transmitters and Energous' WattUp pocket-forming antenna arrays.

Yesterday at CES, we were introduced to Ossia, another company that wants to transform how we power our devices using wireless energy. Ossia's solution, called Cota, uses thousands of tiny antennas to deliver substantial amounts of power directly to embedded receiving antennas in devices located up to 10 meters away. Cota emphasizes safety, efficiency, and reliability, and their technology seems pretty incredible.

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Climate Change Could Challenge the Water Needs of Power Plants

Most power plants need water. As water resources are challenged in coming decades due to climate change, the bulk of the world’s power plants could see reduced capacity, because of water limitations or temperature changes according to a new study published today in Nature Climate Change.

The output of more than than 80 percent of thermoelectric plants could be affected after 2040, according to the research. However, the technologies to mitigate any capacity reductions due to change in water availability already exist.

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