This Tutorial Text covers coatings and surface treatments for energy-efficient windows of many different kinds, for solar collectors, and for radiative coolers. The desired spectral properties of these surfaces are introduced through a discussion of the radiation that prevails in our natural ambience. Emphasized are materials options, coating techniques, experimental data on optical properties, theoretical models for pertinent materials, and optimization studies with regard to practical applications. The book should be of interest to people working R&D in industry, universities, and national and international institutions who are engaged in issues related to energy efficiency and solar energy utilization.