Sunday, January 20, 2013

This past week's energy news from Scientific American

This entry is autoposting while I'm playing Rift with my wife.  While I'm doing so, enjoy these energy-related articles from this past week's online edition of Scientific American.

Scientific American: Novel Solar Photovoltaic Cells Achieve Record Efficiency Using Nanoscale Structures
The devices could lead to better, cheaper solar power
By David Biello
January 17, 2013
Here's how to make a powerful solar cell from indium and phosphorus: First, arrange microscopic flecks of gold on a semiconductor background. Using the gold as seeds, grow precisely arranged wires roughly 1.5 micrometers tall out of chemically tweaked compounds of indium and phosphorus. Keep the nanowires in line by etching them clean with hydrochloric acid and confining their diameter to 180 nanometers. (A nanometer is one billionth of a meter.) Exposed to the sun, a solar cell employing such nanowires can turn nearly 14 percent of the incoming light into electricity—a new record that opens up more possibilities for cheap and effective solar power.

According to research published online in Science—and validated at Germany's Fraunhofer Institute for Solar Energy Systems—this novel nanowire configuration delivered nearly as much electricity as more traditional indium phosphide thin-film solar cells even though the nanowires themselves covered only 12 percent of the device's surface. That suggests such nanowire solar cells could prove cheaper—and more powerful—if the process could be industrialized, argues physicist Magnus Borgström of Lund University in Sweden, who led the effort.
Scientific American: Food versus Fuel: Native Plants Make Better Ethanol
New research reveals that native grasses and flowers grown on land not currently used for crops could make for a sustainable biofuel
By David Biello
January 16, 2013
A mix of perennial grasses and herbs might offer the best chance for the U.S. to produce a sustainable biofuel, according to the results of a new study. But making that dream a reality could harm local environments and would require developing new technology to harvest, process and convert such plant material into biofuels such as ethanol.

Biofuels have become controversial for their impact on food production. The ethanol used in the U.S. is currently brewed from the starch in corn kernels, which has brought ethanol producers (and government ethanol mandates) into conflict with other uses for corn, such as food or animal feed. Already, corn ethanol in the U.S. has contributed to a hike in food costs of 15 percent, according to the Congressional Budget Office, and the U.N. Food and Agriculture Organization blames corn diverted to biofuels for a global increase in food prices.

To see if nonfood plants could be a source of a biofuel the way corn is, researchers followed six alternative crops and farming systems in so-called marginal lands over 20 years, including poplar trees and alfalfa. Such marginal lands face challenges such as soil fertility and susceptibility to erosion.
Scientific American: Lithium-Ion Battery Fires Could Turn Boeing 787 Dreamliner into a Nightmare
By Larry Greenemeier
January 17, 2013
Boeing’s Dreamliner has likely become a nightmare for the company, its airline customers and regulators worldwide. An inflight lithium-ion battery fire broke out Wednesday on an All Nippon Airways 787 over Japan, forcing an emergency landing. And another battery fire occurred last week aboard a Japan Airlines 787 at Boston’s Logan International Airport. Both battery failures resulted in release of flammable electrolytes, heat damage and smoke on the aircraft, according to the U.S. Federal Aviation Administration (FAA).

The FAA on Wednesday ordered U.S. operators to temporarily ground the aircraft to avoid the risk of additional battery fires. Before any Dreamliners resume flight, operators of U.S.-registered 787s will have to demonstrate to the FAA that the batteries are safe. “These battery problems, if not corrected, could result in damage to critical systems and structures, and the potential for fire in the electrical compartment,” according to a statement issued by the FAA, which says it is investigating. The statement makes no mention of GS Yuasa Corp., the company that makes the 787’s batteries, nor does it call upon Boeing specifically to demonstrate battery safety.

In addition to reviewing the aircraft’s design, manufacture and assembly, the FAA says it also will validate that batteries and the battery system on the aircraft comply with the “special condition” the agency issued as part of the 787’s certification. This condition was that Boeing take a series of protective measures to ensure the batteries wouldn’t fail, causing the exact same problems the company now faces. The 787’s short history has been filled with battery and mechanical problems, as outlined in Patrick Smith’s “Ask the Pilot” January 16 blog post.

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