Title: An Optics-Based Approach to Thermal Management of Photovoltaics: Selective-Spectral and Radiative Cooling,
Abstract: For commercial one-sun solar modules, up to 80% of the incoming sunlight may
be dissipated as heat, potentially raising the temperature 20 C - 30 C higher
than the ambient. In the long term, extreme self-heating erodes efficiency and
shortens lifetime, thereby dramatically reducing the total energy output.
Therefore, it is critically important to develop effective and practical (and
preferably passive) cooling methods to reduce operating temperature of PV
modules. In this paper, we explore two fundamental (but often overlooked)
origins of PV self-heating, namely, sub-bandgap absorption and imperfect
thermal radiation. The analysis suggests that we redesign the optical
properties of the solar module to eliminate parasitic absorption
(selective-spectral cooling) and enhance thermal emission (radiative cooling).
Our Comprehensive opto-electro-thermal simulation shows that the proposed
techniques would cool the one-sun and low-concentrated terrestrial solar
modules up to 10 C and 20 C, respectively. This self-cooling would
substantially extend the lifetime for solar modules, with The corresponding
increase in energy yields and reduced LCOE.