Nighttime Photovoltaic Cells: Electrical power generation by optically couping with deep space

Abstract

Photovoltaics possess significant potential due to the abundance of solar power incident on earth; however, they can only generate electricity during daylight hours. In order to produce electrical power after the sun has set, we consider an alternative photovoltaic concept that uses the earth as a heat source and the night sky as a heat sink, resulting in a “nighttime photovoltaic cell” that employs thermoradiative photovoltaics and radiative cooling to output as much as 10 W/m^2 from ambient radiation. This thesis will discuss the principles of thermoradiative photovoltaics, the theoretical limits of coupling a device with deep space, the potential of advanced radiative cooling techniques to enhance their performance, and a discussion of the practical limits, scalability, and integrability of this nighttime photovoltaic concept.