Unlocking the secret to cheaper solar power
July 25, 2016 01:23 PM - American Institute of Physics (AIP) via ScienceDaily
As climate change garners more attention around the world, scientists at the University of Virginia and Cornell University have made critical advances in understanding the physical properties of an emerging class of solar cells that have the potential to dramatically lower the cost of solar energy.
Solar cells remain a focal point of scientific investigation because the sun offers the most abundant source of energy on earth. The concern, however, with conventional solar cells made from silicon is their cost. Even with recent improvements, they still require a significant amount of electricity and industrial processing to be manufactured.
In 2009, energy researchers turned their attention to a class of materials called "metal halide perovskites," or MHPs. They are sprayed on like paint onto solid objects, says Joshua Choi, an assistant professor of chemical engineering at the University of Virginia. As the solution dries, the MHPs crystallize into a thin film that can be used to capture energy in a solar cell.
New lithium-oxygen battery greatly improves energy efficiency, longevity
July 25, 2016 12:31 PM - Massachusetts Institute of Technology via EurekAlert!
Lithium-air batteries are considered highly promising technologies for electric cars and portable electronic devices because of their potential for delivering a high energy output in proportion to their weight. But such batteries have some pretty serious drawbacks: They waste much of the injected energy as heat and degrade relatively quickly. They also require expensive extra components to pump oxygen gas in and out, in an open-cell configuration that is very different from conventional sealed batteries.
But a new variation of the battery chemistry, which could be used in a conventional, fully sealed battery, promises similar theoretical performance as lithium-air batteries, while overcoming all of these drawbacks.
The new battery concept, called a nanolithia cathode battery, is described in the journalNature Energy in a paper by Ju Li, the Battelle Energy Alliance Professor of Nuclear Science and Engineering at MIT; postdoc Zhi Zhu; and five others at MIT, Argonne National Laboratory, and Peking University in China.
Soon solar will be the cheapest power everywhere
July 22, 2016 10:04 AM - Chris Goodall, The Ecologist
Solar is already the cheapest available power across large swathes of the tropics, writes Chris Goodall - its cost down 99.7% since the early 70s. Soon it will be the cheapest electricity everywhere, providing clean, secure, affordable energy for all.
Towards the end of last year, Shell CEO Ben van Beurden made a little-noticed remark. He said that solar would become the "dominant backbone" of the world's energy system.
He didn't give a date for his prediction, or indeed define what 'dominant' means, but he accepted that the sun will eventually provide the cheapest energy source across almost all of the world.
Why Americans waste so much food
July 22, 2016 06:51 AM - Martha Filipic, Ohio State University
Even though American consumers throw away about 80 billion pounds of food a year, only about half are aware that food waste is a problem. Even more, researchers have identified that most people perceive benefits to throwing food away, some of which have limited basis in fact.
A study published today in PLOS ONE is just the second peer-reviewed large-scale consumer survey about food waste and is the first in the U.S. to identify patterns regarding how Americans form attitudes on food waste.
Trees' surprising role in the boreal water cycle quantified
July 21, 2016 04:55 PM - University of Alaska Fairbanks via EurekAlert!
Approximately 25 to 50 percent of a living tree is made up of water, depending on the species and time of year. The water stored in trees has previously been considered just a minor part of the water cycle, but a new study by University of Alaska Fairbanks scientists shows otherwise.
Research published this week in Nature Scientific Reports is the first to show that the uptake of snowmelt water by deciduous trees represents a large and previously overlooked aspect of the water balance in boreal watersheds. The study was led by Jessica Young-Robertson, who worked with other scientists from the National Weather Service and UAF's International Arctic Research Center and Geophysical Institute.
Scientists unlock 'green' energy from garden grass
July 21, 2016 11:52 AM - Cardiff University via EurekAlert!
Garden grass could become a source of cheap and clean renewable energy, scientists have claimed.
A team of UK researchers, including experts from Cardiff University's Cardiff Catalysis Institute, have shown that significant amounts of hydrogen can be unlocked from fescue grass with the help of sunlight and a cheap catalyst.
It is the first time that this method has been demonstrated and could potentially lead to a sustainable way of producing hydrogen, which has enormous potential in the renewable energy industry due to its high energy content and the fact that it does not release toxic or greenhouse gases when it is burnt.
Co-author of the study Professor Michael Bowker, from the Cardiff Catalysis Institute, said: "This really is a green source of energy.
Oceans may be large, overlooked source of hydrogen gas
July 21, 2016 11:33 AM - Duke University via ScienceDaily
Serpentinized rocks formed near fast-spreading tectonic plates under Earth's seafloor could be a large and previously overlooked source of free hydrogen gas, a new study finds. The finding could have far-ranging implications since scientists believe hydrogen might be the fuel source responsible for triggering life on Earth. And, if it were found in large enough quantities, hydrogen could be used as a clean-burning substitute for fossil fuels today.
The finding could have far-ranging implications since scientists believe H2 might be the fuel source responsible for triggering life on Earth. And, if it were found in large enough quantities, some experts speculate that it could be used as a clean-burning substitute for fossil fuels today because it gives off high amounts of energy when burned but emits only water, not carbon.
Recent discoveries of free hydrogen gas, which was once thought to be very rare, have been made near slow-spreading tectonic plates deep beneath Earth's continents and under the sea.
'Perfect storm' brought sea louse epidemic to BC salmon
July 20, 2016 04:52 PM - University of Toronto via ScienceDaily
High ocean temperatures and poor timing of parasite management likely led to an epidemic of sea lice in 2015 throughout salmon farms in British Columbia's Queen Charlotte Strait, a University of Toronto-led study has found.
The sea lice spread to migrating juvenile wild salmon, resulting in the highest numbers of sea lice observed on wild salmon in a decade.
In spring of 2015, a team of U of T ecologists led by postdoctoral researchers Andrew Bateman and Stephanie Peacock found that more than 70 per cent of fish the team sampled in the Strait's Broughton Archipelago had at least one sea louse: the highest prevalence of such parasites since 2005.
"It was sort of a perfect storm of environmental conditions and mismanagement of treatment," says Peacock, a postdoctoral fellow in the U of T's Department of Ecology & Evolutionary Biology when the research was conducted. "A lot of people talk about how sea lice are natural, but in farms, you have these parasites in larger numbers. Juvenile wild salmon are then exposed as they migrate past these areas."
Birds on top of the world, with nowhere to go
July 20, 2016 10:57 AM - University of Queensland via EurekAlert!
Climate change could make much of the Arctic unsuitable for millions of migratory birds that travel north to breed each year, according to a new international study published today inGlobal Change Biology.
The University of Queensland School of Biological Sciences' researcher Hannah Wauchope said that suitable breeding conditions for Arctic shorebirds could collapse by 2070.
"This means that countries throughout the world will have fewer migratory birds reaching their shores," Ms Wauchope said.
Arctic breeding shorebirds undertake some of the longest known migratory journeys in the animal kingdom, with many travelling more than 20,000 kilometres per year to escape the northern winter.
The bar-tailed godwit flies from Alaska to New Zealand in a single flight of 12,000 kilometres without landing.
The study predicts that, in a warming world, migratory birds will become increasingly restricted to small islands in the Arctic Ocean as they retreat north.
Quantifying Tree Loss in Sierra National Forest
July 20, 2016 10:37 AM - NASA Earth Observatory
Mass tree die-offs are sparking worries of fire in California’s Sierra Nevada range. An outbreak of bark beetles, along with persistent drought in the state, have caused many evergreen trees to wither and die.
The damage spread rapidly through the mountains in the fall of 2015 after favorable spring conditions (warm and dry) led to a surge in beetle populations, according to Zach Tane, a remote sensing analyst with the U.S. Forest Service (USFS). The beetles burrow under a tree’s bark and lay their eggs. Once they penetrate the tree’s armor (the bark), they begin to gnaw into its living tissue, the phloem.
“Needles don’t turn red the next day. It’s a slow process of the tree dying, and it has to do with life cycle of bark beetle and how long needles can persist in a green state,” said Tane. “As the population of beetles grows, they can overwhelm the natural defenses of a tree. There’s a tipping point—that’s what happened in Colorado and probably what’s happening here.”