Controlling Thermal Radiation for Power Generation and Climate Mitigation

Thermal radiation plays a central role in energy conversion, yet it is rarely treated as a designable resource in solid-state systems. In this talk, I will discuss how controlling radiative energy exchange with materials and optical structures enables new routes for power generation beyond conventional photovoltaics. I will first describe thermophotovoltaic and thermoradiative devices, where spectral control of emission and absorption allows thermal radiation to be converted directly into electricity, approaching surprisingly high efficiencies under appropriate conditions. I will then show how these same principles extend to passive radiative cooling, where engineered emission to the sky can drive objects below ambient temperature. Leveraging this effect, we recently demonstrated a radiative cooling engine that converts Earth’s ambient thermal radiation into continuous mechanical power at night, without sunlight or active heat input. Together, these examples illustrate how solid-state control of thermal radiation opens new thermodynamic pathways for energy conversion, with implications for scalable devices, hybrid systems, and climate-relevant technologies.

Speaker: Jeremy Munday, UC Davis