In joint research with The University of Tokyo (UTokyo) and Nagoya University, National Institute for Materials Science (NIMS) developed a new material "thermoelectric permanent magnet" exhibiting extremely high transverse thermoelectric conversion performance, and achieved transverse thermoelectric generation with a power density of 56.7 mW/cm2 around room temperature in a thermoelectric-permanent-magnet-based module. When converted into a value per applied temperature gradient, this is not only the world’s highest power density among transverse thermoelectric modules, but a performance even comparable to commercial longitudinal thermoelectric modules. This achievement is expected to lead to thermal energy harvesting and management technologies that can be utilized everywhere magnets are used. This research result was published in Energy & Environmental Science on March 18, 2025.