Improvements in the use of solar energy by infrared satellite
A new technological approach to the use of solar energy by infrared satellite could generate electricity with higher efficiency. ‘s design devised by a team of researchers could improve efficiency by using sunlight to heat a particular material, the infrared radiation would then collected by a photovoltaic cell.
This technique could also make it easier to store energy for later use. In this case, the addition of a further step in the process of energy conversion improves performance, and makes it possible to harness the energy of wavelengths of light normally are wasted. The new method has devised equipment Andrej Lenert, Evelyn Wang, and Ivan Marin Soljačić Celanovic, Massachusetts Institute of Technology (MIT) in the U.S. city of Cambridge. A conventional solar cell silicon based not fail all photons. This is because the conversion of photon energy into electricity requires the photon energy level consistent with a proper value at a feature of the photovoltaic cell material called bandgap.In this assembly, the receiving device is a nanophotonic termofotovoltaico layer comprising carbon nanotubes multi-walled, while the emitter is a one-dimensional photonic crystal of silicon and silicon dioxide.
To address this limitation, the team inserted a receiver-transmitter device bilayer made of the latest materials, including carbon nanotubes and photonic crystals, between sunlight and photovoltaic cell. This intermediate layer collects the sun’s energy in a broad spectrum, raising its temperature. When heated, as would occur with a piece of iron which becomes red hot, emits light of a particular wavelength, which in this case is set to match the band gap of the photovoltaic cell mounted near.
This basic concept has been explored for several years, since in theory, termofotovoltaicos systems could provide a way to circumvent a theoretical limit of the energy conversion efficiency of photovoltaic devices based on semiconductors. This limit, known as Shockley-Queisser Limit imposes a ceiling of 33.7 percent in this efficiency, but the authors believe that the new design with enough termofotovoltaicos advanced solar systems, the efficiency would be significantly higher and could even 80 percent. There have been many practical obstacles to achieve good efficiency in this type of innovative systems. Previous experiments have failed to produce a termofotovoltaico device with greater efficiency than 1 percent. But Lenert and colleagues have produced a test device with an initial efficiency of 3.2 percent, and hope to reach 20 percent efficiency, a value that could be enough to make this technology commercially viable product . From here, start the race as dreamed that 80 percent efficiency.