5.1 Passive Radiative Cooling – Tutor: Juan Carlos Cuevas
Tutor: Juan Carlos Cuevas, juancarlos.cuevas(at)uam.es
Very recently it has been demonstrated that it is possible to cool down a system by simply exposing it to sunlight and without any electricity input . This amazing and counterintuitive possibility, known as passive radiative cooling, could have a significant impact on global energy consumption. This physical phenomenon is based on the idea that the Earth’s atmosphere has a transparency window for electromagnetic radiation between 8 and 13 μm that coincides with the peak thermal radiation wavelengths at typical ambient temperatures. By exploiting this window, one can cool a body on the Earth’s surface by radiating its heat away into the cold out space. While nighttime radiative cooling has been widely studied in the past, only very recently it has been possible to demonstrate this phenomenon during daytime, which is obviously when the demand for cooling is highest. This has become possible due to the use of novel concepts from the field of nanophotonics related to the possibility to largely tune the thermal emission properties of an object . The goal of this project is the theoretical study of the phenomenon of passive radiative cooling. To be precise, the student will learn the fundamentals of thermal radiation that are necessary for the description of this phenomenon. Then, the basic theory will be applied to the search for materials and structures that can improve the efficiency of radiative cooling strategies.
- A.P. Raman et al., Nature 515, 540 (2014); P. C. Hsu et al., Science 353, 1019 (2016); Y. Zhai et al., Science 355, 1062 (2017).