In modern industrial and transportation sectors, the conversion of fossil fuels to energy results in waste heat losses nearly twice the amount of energy actually used, requiring additional fuel consumption to compensate. However, if this waste heat can be effectively recovered and converted into electrical energy, we can significantly enhance overall energy efficiency, reduce dependence on fossil fuels, and mitigate carbon emissions. Our research group aims to realize this potential through thermoelectric generation, ultimately contributing to a more sustainable society. Thermoelectric generation directly converts heat into electricity using a temperature difference. Our research encompasses thermoelectric material synthesis and property control, as well as module design and optimization, bringing together multiple disciplines to improve existing technologies and explore next-generation approaches based on diverse energy conversion principles and device architectures, One examples is transverse thermoelectric effect, in which voltage develops perpendicular to the direction of the applied temperature difference, offering opportunities for large-area, thin, and flexible devices. Through these varied approaches, we aim to develop thermoelectric technologies suited to different heat-source geometries and operating environments.