Thermophotovoltaic

Thermophotovoltaic energy conversion, or TPV, generates electricity directly from heat by aiming the thermal radiation of a hot emitter at a photovoltaic cell tuned to that radiation spectrum, using the same photoemission process as a solar cell but working at far lower source temperatures with multi-junction, non-silicon cells. Because the emitter can be a fuel flame, stored heat or industrial waste heat rather than sunlight, TPV has been proposed for spacecraft radioisotope power in place of thermocouples, for drawing power back out of thermal energy storage, for capturing industrial waste heat, and for portable and off-grid generation. Laboratory efficiency has climbed quickly, from 41 percent in 2022 using stacked semiconductor layers at 2,400 degrees Celsius to a reported 44 percent in 2024 using a silicon carbide emitter at 1,435 degrees Celsius, though real fuel-to-electricity systems remain far less efficient and the technology is still confined to niche uses. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/