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U.S. Hydropower Fleet has Upside Power and Storage Potential

Hydropower has a dowdy, low tech image that conjures visions of concrete and degraded ecosystems. It is mostly shut out of the incentives driving solar, wind and other newer forms of renewable energy. InsideClimate News just dubbed it the “Unloved Renewable.” How wrong this image is according to a first-of-its-kind comprehensive study of the U.S. hydropower industry released by the Department of Energy’s Oak Ridge National Laboratory (ORNL) in Tennessee. 

ORNL researchers found that U.S. hydropower grew by 1.5 gigawatts to 79.6 GW over the past decade, thus holding on to its seven percent share of U.S. power supply. In so doing it is offsetting roughly 200 million metric tons of carbon emissions per year, equivalent to taking more than 42 million cars off the road.

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Micromotors to Boost Hydrogen Fuel Cells

Hydrogen fuel cells promise vehicles whose only emission is water. But their appearance, at least as a one-to-one replacement for internal combustion engines, has been stymied by the challenges of storing hydrogen gas. Now researchers say micromotors could help vehicles generate hydrogen gas on board in order to power hydrogen fuel cells.

Hydrogen fuel cells work by combining hydrogen with oxygen from the air to generate electricity and water vapor. Instead of storing hydrogen gas in bulky pressurized tanks, scientists have suggested storing the fuel in the form of liquids loaded with hydrogen-containing salts such as sodium borohydride, which release hydrogen gas when exposed to a metal catalyst.

Most catalysts that are used to release hydrogen from sodium borohydride have come in the form of either nanoparticles or thin films. But the speed and efficiency with which these systems release hydrogen is limited by deactivation of the catalysts by poor mixing of the fuel or accumulation of the catalytic reactions’ byproducts.

Now scientists at the University of California, San Diego, suggest they have solved these problems by using 20-micron-wide particles that act like self-propelled micromotors. These so-called "Janus particles" have two different faces, just like the Roman god Janus; one side is made of a very fine catalytically active platinum powder, while the other is coated with titanium. They detailed their findings online in the 23 April edition of the journal Angewandte Chemie.

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First X-ray Views Inside Overheating Lithium-ion Batteries

For the first time, scientists have looked inside a lithium-ion battery as it failed due to overheating. The researchers suggest learning more about such "thermal runaways" can help improve the design and safety of these batteries.

When a lithium-ion battery overheats, it can burn through pockets, burst into flames, or even explode. Although such thermal runaways are rare, they do happen regularly enough to lead some engineers to explore the creation of lithium-ion batteries with their own fire alarms or search for signal processing tricks that can predict fires.

To learn more about how thermal runaway happens—and perhaps how to prevent it—scientists at University College London and their colleagues scanned overheating lithium-ion batteries at the European Synchrotron Radiation Facility in Grenoble, France. The image resolution from the X-rays generated at this particle accelerator is far greater than that of conventional X-ray machines. They detailed their findings online in the 28 April edition of the journal Nature Communications.

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The Promise of Precision Agriculture in Drought-Ridden California

When California Governor Jerry Brown announced a mandatory 25 percent cut in water consumption in the coming year for urban areas, many people protested that the state’s agricultural industry, which is responsible for the lion’s share of human water consumption, was not included in the restrictions.

The governor countered that farms, which lap up about 80 percent of the water used in the state, have already made sacrifices and will likely have to make more.

Some Central Valley Project water contractors will face a second year of receiving no water and some San Joaquin Valley irrigation districts are delivering no more than 25 percent of normal supplies, according to the University of California Davis. As more farmers face dwindling supplies, there are variety of high tech tools, including GPS, sensors and big data analytics, to help them manage water supply; if they can get them at the right price. 

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NRC Opposes European Moves to Tighten Nuclear Safety Post-Fukushima

Nuclear power plants’ reactor pressure vessels (RPVs)—the massive steel jars that hold a nuclear plant’s fissioning fuel—face incessant abuse from their radioactive contents. And they must be built with extra toughness to withstand pressure and temperature swings in the event of a loss-of-cooling accident like the one that occurred at Fukushima in 2011. As the triple meltdowns at Fukushima Daiichi showed, the next layer of defense against a nuclear release—the so-called containment vessels—can not be counted on to actually contain molten nuclear fuel that breaches the RPV.

Nuclear safety authorities have recently discovered weaknesses in several RPVs, and their contrasting responses suggest that the ultimate lessons from Fukushima are still sinking into international nuclear power culture—especially in the United States, where the Nuclear Regulatory Commission (NRC) is resisting calls to mandate tougher inspection of RPVs.

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Drought May Force California’s Water System Into the 21st Century

As California withers in its fourth year of extreme drought, Governor Jerry Brown has ordered a mandatory 25 percent cut in water consumption in the coming year for the state’s local water supply agencies that serve urban areas.

Although the current order is short term, it could ultimately help transform how California’s city dwellers use water, especially in terms of how data and analytics aid in conservation.

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New Ultrafast, Long-Lasting Aluminum Battery

A new kind of flexible aluminum-ion battery holds as much energy as lead-acid and nickel metal hydride batteries but recharges in a minute. The battery also boasts a much longer cycle life than today’s battery technologies.

The battery’s low cost, long cycle life and stability are appealing for grid-scale storage, says Hongjie Dai, a professor of chemistry at Stanford University. The technology could also be developed to power wearable devices. Dai and his colleagues reported the details regarding the new device in the journal Nature.

Aluminum-ion batteries are an attractive alternative to lithium-ion batteries for a few reasons. For one, aluminum is abundant and hence cheap. It is less reactive, which would mean safer, less-flammable batteries. In a video, the researchers drill into the batteries and they continue working for a while without catching fire. For the same reasons, many teams are also working on alternatives to lithium batteries that feature potassiumsodium and manganese.

Delving into chemistry, aluminum has three valence electrons compared to lithium’s one. So charge-discharge reactions transfer three electrons per atom, which means an aluminum battery could pack almost three times as much energy as its lithium-ion counterpart, and in a smaller, lighter package.

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Storing Solar Energy: A great idea caught on contested ground

Adding energy storage to sites with rooftop solar power generation offers a range of potential benefits. A battery can help smooth out solar’s inherently variable supply of power to the local grid, and even keep buildings powered during blackouts. Consequently, power-conversion innovators are developing a host of new products designed to reduce the cost and improve the efficiency of integrated solar-storage systems. 

Some analysts project a boom in the co-location of solar and energy storage. GTM Research, for example, foresees that co-located PV and storage will grow from $42 million in 2014 to more than $1 billion by 2018. However, the market is moving slower than it might thanks to a little-discussed regulatory roadblock in the United States.

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