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Politics : The Exxon Free Environmental Thread -- Ignore unavailable to you. Want to Upgrade?

To: Wharf Rat who wrote (2762)	8/1/2008 8:02:48 AM
From: Tom Clarke	Read Replies (1) \| Respond to of 49151

MIT claims 24/7 solar power R. Colin Johnson (07/31/2008 2:00 PM EDT) PORTLAND, Ore. — Researchers at the Massachusetts Institute of Technology have combined a liquid catalyst with photovoltaic cells to achieve what they claim is a solar energy system that could generate electricity around the clock. A liquid catalyst was added to water before electrolysis to achieve what the researchers claim is almost 100-percent efficiency. When combined with photovoltaic cells to store energy chemically, the resulting solar energy systems could generate electricity around the clock, the MIT team said. "The hard part of getting water to split is not the hydrogen -- platinum as a catalyst works fine for the hydrogen. But platinum works very poorly for oxygen, making you use much more energy," said MIT chemistry professor Daniel Nocera. "What we have done is made a catalyst work for the oxygen part without any extra energy. In fact, with our catalyst almost 100 percent of the current used for electrolysis goes into making oxygen and hydrogen." Nickel oxide catalysts are currently used to boost the efficiency of electrolyzers, and they worked equally well in MIT's formulation, Nocera acknowledged. He added that the toxicity of nickel oxide forces the use of expensive, hermetically-sealed water containers. MIT's patented catalyst formulation is "green," Nocera said, and can be used in inexpensive open containers. "Nickel oxide can't be used around anything else in the environment because of corrosion -- even the carbon dioxide in the air will react with it to make carbonates," said Nocera. "But our catalyst uses abundant materials that don't react with environment." MIT's patented formulation of cobalt phosphate was dissolved in water. When the electrical current is passed through it to initiate electrolysis, the catalyst attached itself to the oxygen electrode to increase its efficiency. When the electrical current was turned off, the cobalt phosphate dissolved back into water. The simplicity of the process enables basic electrolyzers to be used, the researchers said. "Because our catalyst is green, the machines that perform electrolysis can be much less expensive than they are today, since they don't need to be protected from environmental contaminants," said Nocera. Currently, MIT is working with photovoltaic cell manufacturers to incorporate electrolysis using their catalyst into solar energy systems. By combining the two, excess capacity during the day could be stored as hydrogen and oxygen, then used in fuel cells at night when needed. "Solar cell makers can add super-cheap electrolyzers to their system so that they work 24/7 -- during the day making hydrogen and oxygen, then at night recombining it in fuel cells to generate electricity," Nocera predicted. Matthew Kanan, a MIT postdoctoral fellow, assisted in the research. Funding was provided by the MIT Energy Initiative, the Chesonis Family Foundation, the Solar Revolution Project and the National Science Foundation. URL: eetimes.com

To: Wharf Rat who wrote (2762)	8/3/2008 12:42:09 AM
From: Wharf Rat	Read Replies (1) \| Respond to of 49151

Radiation exposed Low doses of radiation can cause harm; coal plants worse than nuclear plants Posted by Joseph Romm (Guest Contributor) at 6:45 PM on 02 Aug 2008 The effect of radiation is not a subject I blog on a great deal, although it is a subject I have studied a great deal. Indeed, my uncle, a former nuclear physics professor at MIT, started our family Radon testing business, which was sold off years ago. I asserted that people should be worried about low doses of radiation, especially cumulatively over time. Charles Barton of The Nuclear Green Revolution commented, "Your low doses over time assertion has been repeatedly falsified by empirical studies." Quite the reverse is true. As the National Research Council's Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation (!) reported definitively three years ago: A preponderance of scientific evidence shows that even low doses of ionizing radiation, such as gamma rays and X-rays, are likely to pose some risk of adverse health effects, says a new report from the National Academies' National Research Council ... "The scientific research base shows that there is no threshold of exposure below which low levels of ionizing radiation can be demonstrated to be harmless or beneficial," said committee chair Richard R. Monson, associate dean for professional education and professor of epidemiology, Harvard School of Public Health, Boston. "The health risks -- particularly the development of solid cancers in organs -- rise proportionally with exposure. At low doses of radiation, the risk of inducing solid cancers is very small. As the overall lifetime exposure increases, so does the risk." The research is in fact based on empirical data. You can read the whole NRC report, the seventh in a series on this subject dating back decades, here. Now to be other interesting question: From a radiation perspective, is it worse to live near a coal plant or a nuclear? I'm going to have to go with Oak Ridge National Laboratory on this and say "a coal plant." They actually have a very detailed online analysis, which is a must read for people who don't like coal: Former ORNL researchers J. P. McBride, R. E. Moore, J. P. Witherspoon, and R. E. Blanco made this point in their article "Radiological Impact of Airborne Effluents of Coal and Nuclear Plants" [PDF] in the December 8, 1978, issue of Science magazine. They concluded that Americans living near coal-fired power plants are exposed to higher radiation doses than those living near nuclear power plants that meet government regulations. This ironic situation remains true today and is addressed in this article. The fact that coal-fired power plants throughout the world are the major sources of radioactive materials released to the environment has several implications. It suggests that coal combustion is more hazardous to health than nuclear power and that it adds to the background radiation burden even more than does nuclear power. It also suggests that if radiation emissions from coal plants were regulated, their capital and operating costs would increase, making coal-fired power less economically competitive. Don't hold your breath waiting for such regulations -- unless you live near a coal plant, in which case you should hold your breath. gristmill.grist.org