— Biocompatible graphene transistor array reads cellular signals — Researchers have demonstrated, for the first time, a graphene-based transistor array that is compatible with living biological cells and capable of recording the electrical signals…
— Researchers find some smartphone models more vulnerable to attack — New research from North Carolina State University shows that some smartphones specifically designed to support the Android mobile platform have incorporated additional features that…
— MIT: New algorithm may improve defensive driving — In 2008, according to the National Highway Traffic Safety Administration, 2.3 million automobile crashes occurred at intersections across the United States, resulting in some 7,000…
— Researchers use CT to recreate Stradivarius violin — Using computed tomography (CT) imaging and advanced manufacturing techniques, a team of experts has created a reproduction of a 1704 Stradivarius violin. Three-dimensional images of…
— Terminator-style info-vision takes step towards reality — The streaming of real-time information across your field of vision is a step closer to reality with the development of a prototype contact lens that could potentially provide the wearer…
— Scientists invent long-lasting, near infrared-emitting material — Materials that emit visible light after being exposed to sunlight are commonplace and can be found in everything from emergency signage to glow-in-the-dark stickers. But until now,…
— Team of researchers develop world's lightest material — A team of researchers from UC Irvine, HRL Laboratories and the California Institute of Technology have developed the world's lightest material - with a density of 0.9 mg/cc - about…
— Humans can control a cursor with power of thought — The act of mind reading is something usually reserved for science-fiction movies but researchers in America have used a technique, usually associated with identifying epilepsy, for…
— Inexpensive new instruments test building sealants under real-world conditions — Sealants, like weather stripping, are what separates the inside from the outside of a building, byproviding a barrier that prevents water from seeping in, for example, or heat from…
Nanoparticles improve solar collection efficiency
Using minute graphite particles 1000 times smaller than the width of a human hair, mechanical engineers at Arizona State University hope to boost the efficiency - and profitability - of solar power plants.
Photovoltaic (PV) solar panels are popping up more and more on rooftops, but they're not necessarily the best solar power solution. 'The big limitation of PV panels is that they can use only a fraction of the sunlight that hits them, and the rest just turns into heat, which actually hurts the performance of the panels,' explains Robert Taylor, a graduate student in mechanical engineering at Arizona State University.
An alternative that can make use of all of the sunlight, including light PVs can't use, is the solar thermal collector. The purpose of these collectors - which take the form of dishes, panels, evacuated tubes, towers, and more - is to collect heat that can then be used to boil water to make steam, for example, which drives a turbine to create electricity.
To further increase the efficiency of solar collectors, Taylor and his colleagues have mixed nanoparticles - particles a billionth of a metre in size - into the heat-transfer oils normally used in solar thermal power plants. The researchers chose graphite nanoparticles, in part because they are black and therefore absorb light very well, making them efficient heat collectors. In laboratory tests with small dish collectors, Taylor and his colleagues found that nanoparticles increased heat-collection efficiency by up to 10 percent. 'We estimate that this could mean up to $3.5 million dollars per year more revenue for a 100 megawatt solar power plant,' he says.
What's more, Taylor adds, graphite nanoparticles 'are cheap' - less than $1 per gram - but with 100 grams of nanoparticles providing the same heat-collecting surface area as an entire football field. 'It might also be possible to filter out nanoparticles of soot, which have similar absorbing potential, from coal power plants for use in solar systems,' he says. 'I think that idea is particularly attractive: using a pollutant to harvest clean, green solar energy.'
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