Developing technology:http://www.technologyreview.com/feature ... ear-plant/The consortium says the technology–rooted in research and prototype reactors that date to the 1960s–has matured to the point of achieving the twin goals that have eluded the nuclear industry in the post-Three Mile Island and Chernobyl era: affordability and inherent safety. First, a pebble bed reactor is relatively simple to build and inexpensive to operate; the consortium says construction and operating costs are expected to be “competitive” with those of coal and natural-gas plants. Second, and perhaps more crucial, they say, it is immune to today’s worst-case scenario: a loss of coolant in the reactor core that would lead to a melting of uranium fuel and a catastrophic release of radiation. That’s because the fuel is encased in billiard-ball-sized graphite “pebbles” that can’t get hot enough to melt. What’s more, this encasement may make the spent pebbles more rugged in long-term storage.
The fuel design isn’t the only thing that makes this reactor fundamentally different from the more than 430 commercial nuclear power reactors worldwide, nearly a quarter of which are in the United States.The pebble bed reactor is cooled with helium gas instead of water, operates at higher, more efficient temperatures and–thanks to the inherent safety claimed by its builders–dispenses with the containment dome and regional evacuation plan now required of U.S. nuclear facilities. Individual pebble-bed plants would also have a smaller footprint than today’s plants and produce a mere 100 megawatts or so of electrical power–a tenth as much as today’s typical nuclear behemoth. This modest scale limits the early financial losses many large plants incur by initially glutting the market with electricity, and gives utilities the option of building just what’s needed at first and then adding units later if demand warrants it.
http://www.technologyreview.com/news/52 ... ell-power/A thin sheet of dyed plastic could cut the cost of solar power, particularly for applications that require solar cells to be highly efficient and flexible.
Researchers at the University of Illinois at Urbana-Champaign are using the plastic to gather sunlight and concentrate it onto a solar cell made of gallium arsenide in an experimental set up. Doing so doubled the power output of the cells.
So far, the researchers have shown that the approach works with a single solar cell, but they plan to make larger sheets of plastic dotted with arrays of many tiny solar cells. The approach could either let a smaller solar panel produce more electricity, or make a panel cheaper by reducing the amount of photovoltaic material needed.
http://www.technologyreview.com/news/52 ... into-fuel/New catalysts turn carbon dioxide into fuels faster and more efficiently.
By Kevin Bullis on December 4, 2013
Reusing carbon dioxide emitted by power plants could reduce fossil-fuel consumption.
Making carbon dioxide by burning hydrocarbons is easy. A pair of novel catalysts recently made by researchers at the University of Illinois at Chicago could make it far more practical to do the reverse, converting carbon dioxide and water into fuel.
Because running this reaction normally requires large amounts of energy, it has been economical only in rare cases (see “Company Makes CO2 into Liquid Fuel, with Help from a Volcano”). But if the process could be done commercially, liquid fuels could be made from the exhaust gases of fossil-fuel power plants.
The new work, described this week in the journal Nature Communications, improves on a pair of catalysts discovered last year that more efficiently turn carbon dioxide into carbon monoxide, which can then be made into gasoline and other products. Those catalysts produce carbon monoxide slowly, however, and one is made of silver, so it’s expensive. But the Illinois researchers have demonstrated that it’s possible to replace the silver with relatively inexpensive carbon fibers while maintaining about the same efficiency. And the technique produces carbon monoxide about 10 times faster.
Posted: Tue Dec 24, 2013 4:43 pm
