Awards Database

Scialog: Collaborative Teams - 2013

Michael Bartl

Chemistry, University of Utah

Benjamin Lear

Chemistry, Pennsylvania State University, University Park

Adele Tamboli

Physics, Colorado School of Mines

Eric Toberer

Physics, Colorado School of Mines

Spectrum Splitting for Low-Cost Hybrid PV/Solar Thermal Generation

Currently, no solar energy system manages to achieve the trifecta of cost, efficiency and dispatchability (providing adequate power output on demand). These shortcomings drive up capital costs and make it difficult for solar power, whether photovoltaic or solar-thermal, to compete with fossil fuels. Photovoltaic solar panels generate electricity directly from sunlight, but they must rely on today’s relatively inefficient battery technology to store power; meanwhile, solar-thermal systems are relatively inefficient at extracting energy from visible light, although they have the advantage over photovoltaics when it comes to storing heat to power conventional generators at night. Now a quartet of researchers is trying to create a better system by cleverly combining both types of solar power technologies. They are Michael Bartl, associate professor of physical & materials chemistry, University of Utah; Benjamin Lear, assistant professor of chemistry, Penn State; physicist Adele Tamboli, staff scientist at the National Renewable Energy Laboratory; and Eric Toberer, assistant professor of physics at the Colorado School of Mines. Specifically, the researchers’ initial plan is to develop a pipe-like glass vacuum tube with an inner sealed tube containing a mixture of molten salt and metal oxide nanoparticles. The inner tube of salt and metal will absorb low-energy near- infrared light from the sun to produce heat for storage, while the back of the outer vacuum tube will be lined with a photovoltaic material to absorb high-energy photons from sunlight to produce electricity for immediate use. A big challenge in creating this hybrid system is to come up with a molten salt-and-nanoparticle mixture that absorbs the infrared and, with some luck, perhaps also the ultraviolet portions of sunlight, while allowing most of the visible light to pass through and strike the photovoltaic material on the back side of the vacuum tube. Another challenge is to come up with a hemispherical, mirror-like concentrator to focus the optimum amount of sunlight in the most desirable wavelengths onto the tube system. The first step is to construct a model system to prove their concept can work; if it does, they will likely seek additional funding from government sources. The investigation has received matching funds from the Colorado Energy Research Collaboratory.

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