By L.J. Polintan
University of Michigan researchers have found a way to utilize solar power without the use of solar panels by using magnetic effects.
Stephen Rand, a professor in the departments of Electrical Engineering and Computer Science, Physics and Applied Physics, and his colleagues discovered that at the right intensity, a light field can generate a magnetic effect 100 times stronger than previously thought.
William Fisher, a doctoral student in applied physics, pointed out that this is made possible by previously undetected brand of optical rectification, or an effect wherein electromagnetic waves produce an electrical voltage.
Mr. Rand and Mr. Fisher found that under right circumstances and type of material, they can utilize optical rectification for power.
The researchers found that magnetic field’s electrons curve into a C-shape that moves forward a little each time. This motion generates both an electric and a magnetic dipole. By setting many of these up in a row in a long fiber, huge amounts of voltage can be produced and extracted.
“Instead of the light being absorbed, energy is stored in a magnetic moment. Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power source,” Mr. Rand explained.
He added that since the light in their developed technique does not get absorbed, they expect a very low heat load. His team predicts that this technique can make solar power cheaper and could achieve 10 percent conversion efficiency with improved materials.
“All we would need are lenses to focus the light and a fiber to guide it. Glass works for both,” Mr. Fisher said. “Transparent ceramics might be even better.”
This summer, researchers’ experiments will venture into using laser light and then sunlight for their technique.
Currently, solar power comes from solar panels which are costly and are susceptible to the adverse effects of heat. This technique developed by the university could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation.
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