Researchers of the University of California, Berkeley, set another record in photovoltaic efficiency. According to the scientists, now it’s possible to make an ultralight engine that can power drones for days.
Up to now drones have been powered by heavy battery unit, so the use of thermophotovoltaics can be a true breakthrough: this ultralight alternative power source can allow drones (and not only drones!) to hover for several days. This technology can also be used to power deep space probes for centuries. On Earth, such thermophotovoltaic element the size of an envelope can be a power generator for a house.
According to the researchers, this invention is based on a breakthrough that was made 15 years ago. The thing is that the back of a solar module also can generate electricity if you add a mirror there. Further research showed that a highly reflective mirror could serve double duty. Actually, this phenomenon solves one of the biggest problems in thermophotovoltaics: how to exploit the thermal photons that have too little energy to generate electricity.
As it turned out, such mirror can reflect those small photons to reheat the thermal source, providing a second chance for a high energy photon to be created. This phenomenon leads to unprecedented efficiency.
“We have achieved this record-seting result by just a gold mirror. Now, we’ll add a dielectric layer above the gold, and that will increase the efficiency up to 36 percent,” said Luis M. Pazos Outόn, a postdoctoral researcher in EECS and one of the research paper’s authors.