Researchers have created a concentrating photovoltaic (CPV) system with embedded microtracking that is capable of producing 50 percent more energy per day than the standard silicon solar cells.

“Solar cells used to be expensive, but now they’re getting really cheap,” says Chris Giebink, an assistant professor of electrical engineering at Penn State.

“As a result, the solar cell is no longer the dominant cost of the energy it produces. The majority of the cost increasingly lies in everything else—the inverter, installation labor, permitting fees, etc.—all the stuff we used to neglect,” he says.

This changing economic landscape has put a premium on high efficiency. In contrast to silicon solar panels, which currently dominate the market at 15 to 20 percent efficiency, concentrating photovoltaics focus sunlight onto smaller, but much more efficient solar cells like those used on satellites, to enable overall efficiencies of 35 to 40 percent.

(more…)

Lithium-ion batteries power a vast majority of the world’s portable electronics, from smartphones to laptops. A standard lithium-ion batteries utilizes a liquid as the electrolyte between two electrodes. However, the liquid electrolyte has the potential to lead to safety hazards. Researchers from MIT believe that by using a solid electrolyte, lithium-ion batteries could be safer and able to store more energy. However, most research in the area of all-solid-state lithium-ion batteries has faced significant barriers.

According to the team from MIT, a reason why research into solid electrolytes has been so challenging is due to incorrect interpretation of how these batteries fail.

This from MIT:

The problem, according to this study, is that researchers have been focusing on the wrong properties in their search for a solid electrolyte material. The prevailing idea was that the material’s firmness or squishiness (a property called shear modulus) determined whether dendrites could penetrate into the electrolyte. But the new analysis showed that it’s the smoothness of the surface that matters most. Microscopic nicks and scratches on the electrolyte’s surface can provide a toehold for the metallic deposits to begin to force their way in, the researchers found.

(more…)

In an effort to expand South Australia’s renewable energy supply, the state has looked to business magnate Elon Musk to build the world’s largest lithium-ion battery. The goal of the project is to deliver a grid-scale battery with the ability to stabilize intermittency issues in the area as well as reduce energy prices.

An energy grid is the central component of energy generation and usage. By changing the type of energy that powers that grid in moving from fossil fuels toward more renewable sources, the grid itself changes. Traditional electrical grids demand consistency, using fossil fuels to control production for demand. However, renewable sources such as wind and solar provide intermittency issues that traditional fossil fuels do not. Researchers must look at how we can deliver energy to the electrical grid when the sun goes down or the wind stops blowing. This is where energy storage systems, such as batteries, play a pivotal role.

In South Australia, Musk’s battery is intended to sustain 100 megawatts of power and store that energy for 129 megawatt hours. To put it in perspective, that is enough energy to power 30,000 homes and, according to Musk, will be three times as powerful as the world’s current largest lithium-ion battery.

Musk hopes to complete the project by December, stating that “It’s a fundamental efficiency improvement to the power grid, and it’s really quite necessary and quite obvious considering a renewable energy future.”

(more…)

Around the world, the transportation sector is evolving. Globally, electric vehicle (EV) sales have more than doubled, showing a 72 percent increase in 2015, followed by 41 percent global increase in EV sales in 2016. Now, France is committing to a greener transportation sector by vowing to end the sale of gasoline and diesel vehicles by 2040, further pledging to become a carbon neutral country by 2050.

Currently, 95.2 percent of new car fleets in France are represented by gasoline and diesel vehicles. According to France’s Ecology Minister Nicolas Hulot, initiatives by automakers such as Volvo to go all electric in the coming years will help France start to phase out gasoline and diesel vehicles.

In order to become carbon neutral by 2050, France will also need to devote energy to ending the use of fossil fuels across the board, which includes ending hydrocarbon licenses in the country and stopping coal production by 2022.

While France’s goals are admirable, organizations such as Greenpeace believe that the measure falls short in terms of concrete measures.

“We are left wanting, on how these objectives will be achieved,” Greenpeace campaigner Cyrille Cormier said in a statement. “The goal to end the sale of gasoline and diesel vehicles by 2040 sends out a strong signal, but we would really like to know what are the first steps achieve this, and how to make this ambition something other than a disappointment.”

Scientists have created a nanoscale light detector that can convert light to energy, combining both a unique fabrication method and light-trapping structures.

In today’s increasingly powerful electronics, tiny materials are a must as manufacturers seek to increase performance without adding bulk. Smaller is also better for optoelectronic devices—like camera sensors or solar cells—which collect light and convert it to electrical energy.

Think, for example, about reducing the size and weight of a series of solar panels, producing a higher-quality photo in low lighting conditions, or even transmitting data more quickly.

However, two major challenges have stood in the way: First, shrinking the size of conventionally used “amorphous” thin-film materials also reduces their quality. And second, when ultrathin materials become too thin, they are almost transparent—and actually lose some ability to gather or absorb light.

The new nanoscale light detector, a single-crystalline germanium nanomembrane photodetector on a nanocavity substrate, could overcome both of these obstacles.

“We’ve created an exceptionally small and extraordinarily powerful device that converts light into energy,” says Qiaoqiang Gan, associate professor of electrical engineering in the University at Buffalo’s School of Engineering and Applied Sciences and one of the paper’s lead authors. “The potential applications are exciting because it could be used to produce everything from more efficient solar panels to more powerful optical fibers.”

(more…)

Instead of batteries, a new cell phone harvests the few microwatts of power it needs from a different source: ambient radio signals or light.

Researchers were also able to make Skype calls using the battery-free phone, demonstrating that the prototype—made of commercial, off-the-shelf components—can receive and transmit speech and communicate with a base station.

“We’ve built what we believe is the first functioning cell phone that consumes almost zero power,” says Shyam Gollakota, an associate professor of computer science & engineering at the University of Washington and coauthor of the paper.

“To achieve the really, really low power consumption that you need to run a phone by harvesting energy from the environment, we had to fundamentally rethink how these devices are designed.”

Researchers eliminated a power-hungry step in most modern cellular transmissions—converting analog signals that convey sound into digital data that a phone can understand. This process consumes so much energy that it’s been impossible to design a phone that can rely on ambient power sources.

(more…)

By: Richard B. Rood, University of Michigan

Earth’s climate is changing rapidly. We know this from billions of observations, documented in thousands of journal papers and texts and summarized every few years by the United Nations’ Intergovernmental Panel on Climate Change. The primary cause of that change is the release of carbon dioxide from burning coal, oil and natural gas.

One of the goals of the international Paris Agreement on climate change is to limit the increase of the global surface average air temperature to 2 degrees Celsius, compared to preindustrial times. There is a further commitment to strive to limit the increase to 1.5℃.

Earth has already, essentially, reached the 1℃ threshold. Despite the avoidance of millions of tons of carbon dioxide emissions through use of renewable energy, increased efficiency and conservation efforts, the rate of increase of carbon dioxide in the atmosphere remains high.

International plans on how to deal with climate change are painstakingly difficult to cobble together and take decades to work out. Most climate scientists and negotiators were dismayed by President Trump’s announcement that the U.S. will withdraw from the Paris Agreement.

But setting aside the politics, how much warming are we already locked into? If we stop emitting greenhouse gases right now, why would the temperature continue to rise?

(more…)

In an effort to develop a more affordable, plentiful alternative to lithium-ion batteries, researchers from Purdue University are pursuing rechargeable potassium based batteries, demonstrating a way to derive carbon for battery electrodes from old tires.

“With the growth of rechargeable batteries for electronic devices, electric vehicles and power grid applications, there has been growing concern about the sustainability and cost of lithium,” says Vilas G. Pol, an associate professor in the Davidson School of Chemical Engineering at Purdue University and former member of ECS. “In the last decade, there has been rapid progress in the investigation of metal-ion batteries beyond lithium, such as sodium and potassium.”

Researchers in the field believe that potassium based batteries show potential for large-scale grid storage due to their low cost and the abundance of the element itself.

“The intermittent energy generated from solar and wind requires new energy storage systems for the grid,” Pol says. “However, the limited global availability of lithium resources and high cost of extraction hinder the application of lithium-ion batteries for such large-scale energy storage. This demands alternative energy storage devices that are based on earth-abundant elements.”

(more…)

By: Joshua D. Rhodes, University of Texas at Austin

Science is messy, but it doesn’t have to be dirty.

On June 19, a group of respected energy researchers released a paper in the journal Proceedings of the National Academy of Sciences (PNAS) that critiqued a widely cited study on how to power the U.S. using only renewable energy sources. This new paper, authored by former NOAA researcher Christopher Clack and a small army of academics, said that the initial 2015 study had “errors, inappropriate methods and implausible assumptions,” about using only the sun, wind and water to fuel the U.S.

What followed was a storm of debate as energy wonks of all stripes weighed in on the merits of the PNAS analysis. Mark Z. Jacobson, a Stanford University professor who was the lead author of the 2015 study, shot back with detailed rebuttals, in one calling his fellow researchers “fossil fuel and nuclear supporters.”

Why the big kerfuffle? As an energy researcher who studies the technologies and policies for modernizing our energy system, I will try to explain.

In general, getting to a clean energy system – even if it’s 80 percent renewable – is a well agreed-upon goal and one that can be achieved; it’s that last 20 percent – and how to get there – that forms the main point of contention here.

(more…)

Researchers from Argonne National Laboratory and Oregon State University have developed new cathode architecture for lithium-sulfur batteries. The team, led by ECS member Khalil Amine, incorporated graphene and sulfide nanoparticles to improve electrical conductivity in the promising lithium-sulfur batteries.

Lithium-sulfur batteries hold major promise as researchers explore the range of energy storage technologies. With an extremely high theoretical energy density, these batteries have the potential to store up to five times as much energy as today’s best lithium-ion battery.

But there are barriers preventing that theoretical density from becoming an actual density. Namely, the discharge products of sulfur electrodes and cycling intermediates produced.

(more…)