11-29-04
NSF Grant Continues Research to Develop Cheaper Solar Power
A physics professor at Penn State Erie, The Behrend College, recently received a three-year National Science Foundation grant of $179,468 to continue an interdisciplinary research collaboration with scientists at Molecular Probes, Inc., of Eugene, Oregon. The collaborative effort is aimed at extending the useful life of the multiple-dye luminescent solar concentrator panels that he has been developing since 2000 with support from a previous NSF grant. The initial three-year NSF grant totaled $151,500.
"As we attempt to limit our use of fossil fuels, solar power is becoming increasingly important as an energy source," said Bruce Wittmershaus, associate professor of physics at Penn State Behrend. "The main reason we do not have photovoltaic solar panels on our roofs is because they are too expensive. With our first NSF grant we were able to demonstrate that multiple-dye luminescent solar concentrators work well to collect solar energy, so our next step is to reduce the costs involved in using them."
Wittmershaus proposes to reduce the cost of the luminescent solar concentrator panels by extending their life. He knows that the panels degrade with use, and that the most likely cause is oxidation. In addition to studying oxidation, his research will include tests to determine other chemical causes for degradation. As he learns the causes, he will also search for ways to prevent it.
Two major concepts underlie Wittmershaus' research. The first is to combine the dyes used in the panels so they collectively absorb almost all the visible light from the sun. Ideally, the panels appear black.
The second is the concept of total internal reflection. Fluorescent light from the dyes with an incident angle greater than forty-two degrees is trapped by reflection on the panel's surface. About 74 percent of the trapped light is brought to the edge of the panel, where it is efficiently absorbed by photovoltaic cells that will convert it to electricity.
"As a result of total internal reflection, a clear, flat surface colored by a single fluorescent dye will trap energy. But in this research we are using multiple dyes, so that the least amount of light is reflected and the most possible light is trapped for conversion to solar energy," said Wittmershaus. "This is not necessarily more efficient than other solar energy concentrators, but it is definitely less expensive."
In conducting his research, Wittmershaus has already involved more than a dozen undergraduate students and expects to involve even more as he implements his second NSF grant. He believes that student involvement is one of the best parts of research.
"Research is very similar to the work environment and very different from the classroom," he said. "Hands-on undergraduate research activity is one of the best products of grant funding." He points out that students were co-authors on the three research papers that resulted from the first NSF grant and will also be involved in publications resulting from the second.
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Contact: Loretta Brandon, 814-898-6063, lzb6@psu.edu