Radiative cooling for continuous thermoelectric power generation in day and night

Harvesting energy from the environment often suffers from discontinuity in power generation. Typical examples of technologies where this problem occurs are photovoltaics and solar heat power generation, which can only generate power during the day. In this study, the temperature difference caused by radiative cooling is utilized to generate thermoelectric power continuously throughout the day. The emitter has a wavelength-selective emissivity such that it is radiatively cooled all the time and its surface temperature is always cooler than the bottom side of the thermoelectric module which is placed below the selective emitter. The device placed outdoor generates thermoelectric voltage during the day and night without dropping to zero. The device can be used as a power supply for sensors and monitors placed outdoors.