The BEAT News – June 23, 2016

 Ultra-thin solar cell is flexible enough to wrap around a pencil

By Megan Treacy
Treehugger
June 21, 2016

Flexible, thin-film solar cells are widely considered the future of power generation. Large, rigid panels will likely continue to be the source of large-scale power generation, but bendable solar panels could be placed on any surface from pillars to clothing, which opens up the possibility of gadgets, sensors and more being self-powered.

Scientists in South Korea have pushed the technology forward by creating an ultra-thin solar cell that is so flexible it can bend around a standard pencil without causing damage or stress on the solar cell.

The solar photovoltaic cell is only one micrometer thick, which is far thinner than a human hair, while most thin-film solar cells are between two and four micrometers thick. That extreme thinness is what lets it wrap around something so small.

The solar cell is made from the semiconductor gallium arsenide and then stamped directly on a flexible metal substrate without using an adhesive, which would have added thickness. The cell was fused with the electrode on the substrate by using a cold welding process where pressure was applied at 170 degrees Celsius. The metal bottom layer also acted as a reflector to direct light back towards the solar cell.

In testing they found that the cell was flexible enough to bend around a radius as small as 1.4 millimeters and the solar cells themselves had an energy conversion efficiency similar to thicker thin-film ones. The solar cells also experienced one quarter of the strain from the bending that a cell 3.5 micrometers thick would experience.

“The thinner cells are less fragile under bending, but perform similarly or even slightly better,” said Jongho Lee, an engineer at the Gwangju Institute of Science and Technology in South Korea.

The solar cells could be used in wearable electronics, smart glasses, fabric or integrated into any lower power device that needs to be self-powered like environmental sensors placed in remote areas where it would be difficult to replace batteries or sensors that monitor the health of bridges or buildings.

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Iceland Carbon Capture Project Quickly Converts Carbon Dioxide Into Stone

By Sarah Zielinski
smithsonian.com
June 9, 2016

A pilot project that sought to demonstrate that carbon dioxide emissions could be locked up by turning them into rock appears to be a success. Tests at the CarbFix project in Iceland indicate that most of the CO2 injected into basalt turned into carbonate minerals in less than two years, far shorter a time than the hundreds or thousands of years that scientists had once thought such a process would take.

“This project shows that, in fact, CO2 most likely turns into carbonates in a relatively modest amount of time,” notes David Goldberg, a geophysicist at the Lamont-Doherty Earth Observatory of Columbia University who was not involved with the project. “That’s a significant outcome.”

Most conventional carbon capture and storage projects inject liquefied carbon dioxide into sedimentary rocks, the type of rocks in which oil and natural gas are found. Because oil and gas companies have so much experience working with these types of rocks, they are a natural place to store CO2. But these types of formations can only store the gas, not turn it into rock. And there is always a danger that the gas could escape to the atmosphere and add to global climate change.

The mineralogy of basalts, though, is very favorable for locking up carbon dioxide, says Juerg Matter, a geochemist now at the University of Southampton who began working on the CarbFix project while at Lamont-Doherty. For carbon dioxide to transform into carbonate, the rocks into which the gas is injected need to have calcium-, magnesium- or iron-rich silicate minerals. A chemical reaction then occurs that converts the carbon dioxide and minerals into a chalky carbonate mineral. Sedimentary rocks don’t have much of those minerals, but basalts—a type of volcanic rock that makes up most of the ocean floor as well as rocks on some other places on land—have plenty. Scientists figured that they should be able to lock away CO2 in such rocks as carbonate, but first they had to prove that it would work—and on a reasonable timescale.

In 2012, scientists injected 230 tons of carbon dioxide into basalt rocks near the Hellisheidi geothermal plant east of Reykjavik. Unlike in more conventional carbon storage facilities, the gas was first dissolved into water (creating something like Perrier, notes Goldberg).

Because seeing what is going on underground is difficult, the scientists also included a set of tracers that would later allow them to see the fate of that CO2. First, they included two chemicals, sulfur hexafluoride and trifluoromethyl sulfur pentafluoride, that let them trace the movement of the injected fluid underground. And they also added a small amount of radioactive carbon-14 to their carbon dioxide mix.

“It’s kind of a smart tracer,” Matter says. “In deep reservoirs, like the one we used to store CO2, all the carbon that preexisted in the reservoir before the injection has no radiocarbon in it. It’s too old.” So when the team later went looking for carbonate, if it had radiocarbon, the researchers knew that it most likely came from the gas they injected.

Those tracers let the scientists quantify what happened to the carbon dioxide after the injection. More than 95 percent turned into carbonate within the following two years, they report today in Science.

“The results are very encouraging,” says Peter McGrail, an environmental engineer at the Pacific Northwest National Laboratory. “They’ve done a pretty excellent job in terms of the design of that field study,” he says, and particularly with the use of the two methods of tracing the fate of the carbon.

McGrail is heading up a similar project that injected supercritical—liquid—carbon dioxide into basalt rocks near Wallula, Washington. The outcome of that project will be published soon, but McGrail says that his group is seeing similar results to what the CarbFix project has found.

While these results are promising, questions remain about whether the technology can be scaled up to industrial-size storage, socking away a million tons of carbon dioxide or more. (That’s not much in terms of overall global emissions, which are hovering around 38 billion tons a year.) The CarbFix method would require a lot of water at that scale. And both of the basalt pilot projects can’t predict if the necessary chemical reactions will be sustained underground with so much more carbon dioxide, McGrail says.

Matter notes that 10,000 tons of carbon dioxide have now been injected into another site in Iceland, but testing larger quantities there would be difficult because “there’s not that much CO2 in Iceland.” It’s a small country with relatively small carbon emissions.

Cost also remains a concern. The CarbFix method costs much more than conventional carbon capture and storage methods, but it wouldn’t require the same kind of extensive monitoring since there would be little risk of gas leakage. Without any kind of political or economic framework for storing carbon, however, this is all moot. Right now, Matter notes, “it’s free to pollute the atmosphere.”

But should such incentives be implemented, carbon capture and storage, in all its forms, could become a bigger part in how humans deal with the problem of greenhouse gases, both Goldberg and Matter say. “It’s not a silver bullet solution,” Matter says, but it could provide a bridge between our fossil-fuel past and a renewable energy future.

Read more: http://www.smithsonianmag.com/science-nature/iceland-carbon-capture-project-quickly-converts-carbon-dioxide-stone-180959365/#5w93kDL08Gd0sX7X.99
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China’s plan to cut meat consumption by 50% cheered by climate campaigners

By Oliver Milman and Stuart Leavenworth
The Guardian
June 20, 2016

The Chinese government has outlined a plan to reduce its citizens’ meat consumption by 50%, in a move that climate campaigners hope will provide major heft in the effort to avoid runaway global warming.

New dietary guidelines drawn up by China’s health ministry recommend that the nation’s 1.3 billion population should consume between 40g to 75g of meat per person each day. The measures, released once every 10 years, are designed to improve public health but could also provide a significant cut to greenhouse gas emissions.

The Chinese Communist party has found unusual allies among Hollywood celebrities, with actor Arnold Schwarzenegger and director James Cameron involved in a series of new public information adverts encouraging Chinese people to consume less animal flesh to help the environment.

Should the new guidelines be followed, carbon dioxide equivalent emissions from China’s livestock industry would be reduced by 1bn tonnes by 2030, from a projected 1.8bn tonnes in that year.

Globally, 14.5% of planet-warming emissions emanate from the keeping and eating of cows, chickens, pigs and other animals – more than the emissions from the entire transport sector. Livestock emit methane, a highly potent greenhouse gas, while land clearing and fertilizers release large quantities of carbon.

“Through this kind of lifestyle change, it is expected that the livestock industry will transform and carbon emissions will be reduced,” said Li Junfeng, director general of China’s National Center on Climate Change Strategy and International Cooperation.

“Tackling climate change involves scientific judgement, political decisions, entrepreneurial support, but at last, it still relies on involvement of the general public to change the consumption behavior in China. Every single one of us has to believe in the low-carbon concept and slowly adapt to it.”

Meat has gone from rare treat to a regular staple for many Chinese people. In 1982, the average Chinese person ate just 13kg of meat a year and beef was nicknamed “millionaire’s meat” due to its scarcity.

The emergence of China as a global economic power has radically altered the diets of a newly wealthy population. The average Chinese person now eats 63kg of meat a year, with a further 30kg of meat per person expected to be added by 2030 if nothing is done to disrupt this trend. The new guidelines would reduce this to 14kg to 27kg a year.

China now consumes 28% of the world’s meat, including half of its pork. However, China still lags behind more than a dozen other countries in per capita meat consumption, with the average American or Australian consuming twice as much meat per person compared to China.

According to a new report by WildAid, the predicted increase in China’s meat consumption would add an extra 233m tonnes of greenhouse gases to the atmosphere each year, as well as put increased strain on the country’s water supply, which is already blighted by polluted and denuded rivers and groundwater.

The report warns that unchecked Chinese meat consumption will also degrade its arable land and worsen the country’s problems with obesity and diabetes. An estimated 100 million Chinese people have diabetes, more than any other country.

Research released by the thinktank Chatham House in 2014 forecast that China alone is expected to eat 20m tonnes more of meat and dairy a year by 2020 and warned that “dietary change is essential” if global warming is to not exceed the 2C limit eventually imposed at the climate accord in Paris last year.

A separate report by scientists at the Oxford Martin School this year found that the widespread adoption of vegetarianism around the world could bring down greenhouse gas emissions by nearly two-thirds.

“China’s move to cut meat consumption in half would not only have a huge impact on public health, it is a massive leadership step towards drastically reducing carbon emissions and reaching the goals set out in the Paris agreement,” said James Cameron.

“Animal agriculture emits more than all transportation combined. Reducing demand for animal-based foods is essential if we are to limit global warming to 2C as agreed at COP21.”

Despite the Chinese government’s new commitment to reducing meat consumption, it may be difficult to convince the country’s rising middle classes to cut down. There are also strong cultural traditions attached to the eating of many animals, especially pigs. The Chinese character for “home” depicts a pig underneath the roof of a house.

Recently, Chinese companies have been buying farms in the United States and Australia to provide feed for the country’s dairy and beef industries.
In late 2013 a Chinese company, Shenghui, purchased the largest US pork producer, Smithfield Foods, to help keep up with demand.

“China’s consumption of meat is skyrocketing,” said Jeremy Haft, an adjunct professor at Georgetown University in Washington, DC and author of a 2015 book, “Unmade in China: The Hidden Truth about China’s Economic Miracle.”

“China’s demand for meat will continue to grow and support hundreds of thousands of jobs in the US meat industry,” he added. “From a climate perspective, the methane will still be created, but will be shifted to the United States.”