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A transient battery hooked to a multimeter by alligator clips shows an output of 2.5 volts.

This Battery Will Self-Destruct in 30 Minutes

Electronics that self-destruct over time could be the key to military applications to help keep secrets out of enemy handsmedical implants that don't need surgical removal, and environmental sensors that melt away when no longer needed. Now scientists at Iowa State University say they have developed the first practical transient battery to power them.

Recently, scientists have developed a wide range of transient electronics that can perform a variety of functions until exposure to light, heat, or liquids triggers their self-destruction. Until now, however, these devices largely relied on external power sources that were not transient themselves.

Early research into transient batteries led to devices with limited power, stability, and shelf life. They were also slow to destroy themselves, says Reza Montazami, a materials scientist at Iowa State University who led the effort to invent a better transient battery. Now Montazami and his colleagues have developed a transient battery that can power a desktop calculator for about 15 minutes and destroy itself in about 30 minutes.

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A schematic of the device

Electrochemical Cell Makes Electricity and Chemicals From CO2

Using aluminum and oxygen, new technology can convert carbon dioxide into useful chemicals and also generate substantial amounts of electrical energy, researchers say.

The large-scale adoption of carbon capture, utilization and sequestration (CCUS) technologies is currently limited in part by how much energy it can take to capture carbon. In addition, methods to make the most of carbon dioxide once it gets stored by converting it into useful chemicals and fuels have proven difficult to develop.

But recently, chemical engineer Lynden Archer and his colleagues at Cornell University investigated whether electrochemical cells could both capture carbon dioxide and generate power. Such electrochemical cells, they hypothesized, would use a metal as the anode and mixed streams of carbon dioxide and oxygen as the active ingredients of the cathode. The electrochemical reactions between the anode and the cathode would sequester the carbon dioxide into carbon-rich compounds while also producing electricity.

Archer and his colleague Wajdi Al Sadat detailed their findings in the 20 July online edition of the journal Science Advances.

Previous research used lithium, sodium, and magnesium as the anodes in such electrochemical cells. These converted carbon dioxide into carbonates, “which are not that useful,” Archer says. “It then occurred to us to use aluminum, which is the third most abundant element in Earth's crust.” Aluminum's abundance makes it cheap, and it is also less chemically reactive than lithium and sodium, which makes it safer to work with, Archer adds.

In the new device, the anode consists of aluminum foil, the cathode consists of a porous, electrically conductive material such as a stainless steel mesh that allows carbon dioxide and oxygen to pass through it, and the electrolyte bridging the anode and cathode is a liquid through which molecules can diffuse.

In experiments, the electrochemical cell could generate as much as 13 ampere-hours for each gram of carbon it captured, without the need for a catalyst or high temperatures. Moreover, it converted carbon dioxide into aluminum oxalate, which, in turn, is easily converted into oxalic acid, a chemical widely used in industry. “It's a versatile product that's a nice starting material for plastics and so forth,” Archer says. In theory, adding extra compounds to the cathode might help convert carbon dioxide to other useful chemicals, Archer adds.

Archer notes that the electrolyte in his group’s electrochemical cell does not work if exposed to water. This is a problem because the carbon dioxide emissions that this device might treat, such as those from factories or power plants, might be loaded with moisture. However, it might be possible to find an electrolyte that is much less sensitive to water, Archer says.

A box on a utility pole is a micro phasor measurement unit (microPMU), which could be a useful too in grid cybersecurity

Detecting Cybersecurity Threats by Taking the Grid's Pulse

Power quality expert Alex McEachern set out to build an advanced power sensor for utility distribution grids, and accidentally produced a promising tool to protect power grids from cyber attack. The equipment–developed by McEachern and collaborators at the University of California Berkeley and Lawrence Berkeley National Laboratory—is part of the starter pack for military installations competing in a $77 million power grid cyber security R&D contest that DARPA is kicking off next month. 

“What we’re trying to do is to take the most sensitive instruments that have ever been made for looking at the grid, and looking at what they might be able to see from inside military bases,” says McEachern, who is president of Alameda, Calif.-based power quality firm Power Standards Lab.

Defending against cyber attacks is a mission with new urgency following the Internet-based disruption of Ukraine’s power grid in December 2015—a sophisticated hack planned and executed over more than six months by what is widely thought to be a well-financed team within Russia. Cybersecurity experts called that attack a wake-up call for North American utilities, which are just beginning to invest in network monitoring and other active defenses for their industrial control systems. 

DARPA says it may take “many years” for U.S. utilities to mount effective defenses against what could be devastating attacks. "Beyond the severe domestic impacts, including economic and human costs, prolonged disruption of the grid would hamper military mobilization and logistics, impairing the government’s ability to project force or pursue solutions to international crises,” wrote the agency in a December 2015 release announcing its Rapid Attack Detection, Isolation, and Characterization Systems (RADICS) program.

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Simulated measurement of methane emissions from French Guyana's “Petit Saut” hydroelectric power plant

Satellite Tracks Carbon Polluters From Space

Attention greenhouse gas emitters: There’s a new eye in the sky that will soon be photographing your carbon footprint and selling the images to any and all. It’s a micro-satellite dubbed “Claire” (clear, bright, and clean in French) by its Montreal-based developer, GHGSat.

This microwave-oven-sized pollution paparazzo rocketed to a 512-kilometer-high orbit in mid-June care of the Indian Space Agency, with a mission to remotely measure the plumes of carbon dioxide and methane wafting up from myriad sources on Earth’s surface. Claire's targets include power plants, natural gas fracking fields, rice paddies, and much more—just about any emissions source that someone with a checkbook (corporations, regulators, activists) wants tracked, according to GHGSat president Stéphane Germain.

Germain says Claire’s data can improve compliance reporting to regulators and carbon markets, enable tracking of industrial efficiency, and provide competitive intelligence, among other uses. "Our vision is to be the global standard for emissions monitoring across the world. That’s ambitious, but we think it's attainable,” he says.

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A satellite image of India at night shows the reach of electricity

Electrification Causes Economic Growth, Right? Maybe Not

Electrification is associated with a seemingly endless list of social and economic goods. Nations that use more power tend to have increased income levels and educational attainment and lower risk of infant mortality, to name but a few. So I was baffled to stumble across a pair of economic analyses on electrification in India and Kenya, posted last month, that cast serious doubt on what has long assumed to be a causal link between the glow of electricity and rural development. 

“It is difficult to find evidence in the data that electrification is dramatically transforming rural India,” concludes Fiona Burlig, a fourth-year UC Berkeley doctoral student in agricultural and resource economics who coauthored the India study. “In the medium term, rural electrification just doesn't appear to be a silver bullet for development.”

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A truck drives past a wind farm in Xinjiang, China.

Wind Could Provide 26% of China's Electricity by 2030

Last month Energywise argued that the primary reason Chinese wind farms underperform versus their U.S.-based counterparts is that China’s grid operators deliberately favor operation of coal-fired power plants. Such curtailment of wind power has both economic and technical roots, and it has raised serious questions about whether China can rely on an expanding role for wind energy. New research published today appears to put those concerns to rest, arguing that wind power in China should still grow dramatically. 

The report today in the journal Nature Energy projects that wind energy could affordably meet over one-quarter of China's projected 2030 electricity demand—up from just 3.3 percent of demand last year.

In fact the researchers, from MIT and Tsinghua University, project that modest improvements to the flexibility of China’s grid would enable wind power to grow a further 17 percent. That, they argue, means that China's non-fossil resources could grow well beyond the 20 percent level that China pledged to achieve under the Paris Climate Agreement.

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Perovskite solar cells made with vacuum-flash that surpass 20% efficiency.

Bigger and Better Perovskite Solar Cells

Solar cells based on crystals known as perovskites have advanced by leaps and bounds in recent years. Now scientists have found a way to increase perovskite solar cell size while maintaining the device’s high conversion efficiencies.

In the span of less than a decade, the conversion efficiency of perovskite solar cells has grown from 3.8 to 22.1 percent, an unprecedented rise in the field of photovoltaics. Such devices are also appealing because they are much cheaper to make than the silicon wafers used in conventional solar cells.

However, a major drawback of high-efficiency perovskite solar cells is how small they generally are, ranging from 0.04 to 0.2 square centimeters. Currently, the best conversion efficiency of a perovskite solar cell larger than 1 square centimeter is 15.6 percent.

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Modi and Obama Backstop Indian and Global Climate Action

The leaders of the world’s two biggest democracies—the U.S. and India—pledged at a White House meeting yesterday to complete their countries’ ratification of the Paris climate agreement by the end of 2016—a move that would bring the treaty into force before President Barack Obama leaves office. Obama and Prime Minister Nahendra Modi also announced specific actions on energy and climate in a joint statement, including: 

  • Initiation of preparatory work on a 6-reactor, 6.6-gigawatt nuclear power complex in India to be built by Westinghouse Electric, Toshiba Corp.’s U.S.–based nuclear engineering subsidiary.
  • A resolution to jointly broker an international agreement by the end of this year on the phaseout of hydrofluorocarbon (HFC) refrigerants, which are potent greenhouse gases.
  • New financing programs to catalyze renewable energy investments in India.

Phasing out HFCs could take a big bite out of projected global climate change this century, according to Andrew Light, a former advisor to U.S. Department of State on climate change policy and India and a fellow with the Washington, D.C.–based World Resources Institute. HFCs warm Earth’s atmosphere thousands of times more, molecule-for-molecule than CO2. Light says amending the Montreal Protocol to end their use by 2030 could, “avoid half a degree Celsius of warming by the end of the century.”

Reactor construction by Westinghouse, meanwhile, would culminate years of work to bring to India Western nuclear technology and financing (first approved for India by the U.S. Congress in 2008). The joint statement said engineering and site design for six AP1000 reactors would start “immediately” in the state of Andhra Pradesh. Obama and Modi set a June 2017 deadline for the U.S. Export-Import Bank to finalize a financing package. 

Nuclear remains a long road for India, however. India has been trying to grow its nuclear power sector since the 1950s, and currently has just 5 GW of capacity generating about 3 percent of the country’s power. Reactor projects can take a decade to complete. Light at WRI says it would take a “huge acceleration in construction” for nuclear power plants to meaningfully contribute to India’s power supply by 2030. Plus, adds Light, “costs have to make sense.”

Solar is now India’s energy source to beat on both cost and speed. Solar installations doubled last year and could double again this year. By 2020 India’s solar farms could be generating more gigawatt-hours of energy than the nuclear sector.

Much of the credit goes to the ambition of Modi, who has championed rural electrification and renewables since his election in 2014. Under Modi, reverse auctions and other supportive policies have cut solar energy costs to below 5 rupees (7.5 U.S. cents) per kilowatt-hour—lower than India’s average wholesale power rate. Indian energy minister Piyush Goyal recently stated that solar farms are cheaper than building new coal-fired power plants

Modi pledged in 2014 to boost India’s non-hydro renewable power capacity to 175 GW by 2022, including 60 GW of utility-scale solar farms and 40 GW of rooftop solar. At the time many experts called those goals wildly ambitious, but an increasing number express confidence that the utility-scale solar goal  at least is achievable. 

India will meet its 12 GW goal for the current fiscal year (which ends in March 2017), predicts Ajay Mathur, director general for The Energy and Resources Institute (TERI), a New Delhi–based NGO. “The spadework for that capacity is already done,” says Mathur, noting that government auctions have secured 15-GW worth of commitments.

What India needs most to sustain its renewable energy upswing, says Mathur, is access to cheap capital. Cheaper capital is one reason why reverse auctions elsewhere are yielding unsubsidized utility-scale solar bids twice as cheap as India’s.  WRI’s Light agrees: “The absolute key for India to hit its 2022 targets is cost of capital and finance.”  

Investment in non-hydro renewables in India rose 22 percent last year to US $10.2 billion, according to the United Nations Environment Programme. But that sum is dwarfed by the $102.9 billion that China invested. 

Modi and Obama’s meeting produced two renewable energy finance programs that could help. They appear small, but White House spokesman Brian Deese told reporters yesterday that they could facilitate much larger infusions of private and institutional capital. 

The Center for American Progress’ ClimateProgress blog, citing Deese, writes that a new $20-million U.S.–India Clean Energy Finance initiative will provide early-stage “risk capital” intended to mobilize up to $400 million in private capital by 2020. Another $40-million fund targeted primarily to microgrid projects in unelectrified villages, the U.S.–India Catalytic Solar Finance Program, promises to catalyze projects worth up to $1 billion.

Speaking of unelectrified villages, Modi’s government claims to be crushing his promise to give all citizens access to electricity by 2022. The International Energy Agency reported last year that 240 million people in India lack access to electricity, and by the Indian government’s count there were 18,452 villages lacking grid connections in April 2015.

But the number of powerless villages is in free-fall according to the government’s online electrification dashboard. It claims that power grid extensions have already electrified over 7,000 villages since last April, while microgrids have electrified another 558 villages.

An artist's rendering of EMBR Labs' thermoelectric wearable by Italian designer Niccolo Casas.

Wristify: Thermoelectric Wearable Would Reduce Energy Consumption

Last week Computex, the largest ICT trade show in Asia, was accompanied by record breaking heat (38.7ºC). So it should be no surprise that Wristify, a thermoelectric bracelet, was popular with visitors to the Taipei show.

Wristify, invented by MIT startup EMBR Labs, works because the wrist is rich with blood-flow, so the cold provides quick relief. Similarly, it could also rapidly warm up a shivering skirt-wearing lady (your reporter) who’d been in an air-conditioned room for hours.

“… anytime you’re feeling too hot, too cold, stressed, or anything like that, you can basically control the sensation that you have on your skin and that can produce the overall effective, feeling better,” says co-founder David Cohen-Tanugi. 

The watch-shaped prototype wearable is manually controlled, letting the user adjust the temperature to their preferred level.  The team is adding intelligence so that a future product will be able to automatically adapt, according to Cohen-Tanugi. And the company is in the final preparations for a public launch of product pre-orders, which should happen by the end of September, he says.

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