More than two-thirds of the energy used worldwide is ultimately ejected as "waste heat." Within that reservoir of discarded energy lies a great and largely untapped opportunity, claim scientists in MIT's Department of Nuclear Science and Engineering (NSE). As reported in a recent issue of Nature Communications, the MIT team—led by Assistant Professor Mingda Li, who heads NSE's Quantum Matter Group—has achieved a breakthrough in thermoelectric generation, which offers a direct means of converting thermal energy, including waste heat, into electricity.
source https://techxplore.com/news/2020-12-cool-advance-thermoelectric-conversion.html
