Solar Radiation

In this chapter, availability of solar radiation in extra-terrestrial as well terrestrial region has been discussed as a function of nth day of year, sun-earth angles. Many examples have been given for students/researchers working in the area of solar energy and desire to do research. Examples will also help to evaluate solar radiation on any inclined with any orientation to do thermal modeling of any solar thermal (ST), photo-voltaic (PV) and photo-voltaic thermal (PVT) systems even without knowing beam and diffuse radiation on horizontal surface.