Heating-Up Solar Panel Efficiencies

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Researchers at Massachusetts Institute of Technology (MIT) have developed a new method of collecting solar energy to improve system efficiency. This technique incorporates both a traditional photovoltaic (PV or Solar) cell and a high-temperature material, which is heated directly by sunlight and the radiated infrared energy is collected by the traditional system. This process allows the usage of light wavelengths that are ignored as unusable and may also improve energy storage for later use. Evelyn Wang, associate professor of mechanical engineering at MIT and a co-author of the paper “A nanophotonic solar thermophotovoltaic device”, explained that a conventional silicon-based solar cell “doesn’t take advantage of all the photons.” In order to convert sunlight into electricity, the energy level of a photon must match a characteristic of the PV material called a bandgap. Silicon, which is used in conventional solar cells, has a bandgap that responds to many wavelengths of light, but misses many others. By inserting a two-layer absorber-emitter device, which is composed of novel materials such as carbon nanotubes and photonic crystals, this intermediate layer collects energy from a broader spectrum of light and heats up. As with a piece of iron that glows red, yellow, or white hot, any heated material emits energy on a particular wavelength. If that wavelength matches the bandgap of the solar cell, then that energy can be successfully converted into electricity. This technology, however, is still in its infancy. To date only a 3.2% efficiency has been reached on 1-centimeter chips, but further testing on 10-centimeter chips could potentially raise this to 20% efficiency. This additional utilization of previously discarded wavelengths could lead to a 50% to 100% improvement over today’s conventional solar cells. Total system efficiency could rise from a peak of 44% today to over 80% within a decade. This would allow either double the solar energy to be collected by households for a full roof system or reduce the footprint, which is needed to meet the family electricity needs, by half. this company does a SEO search engine optimization experts

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