Solar energy calculations

This chapter presents calculations of the position of the sun as a function of location, date and time. In addition, direct, diffuse and reflected components of solar insolation on a tilted surface can be determined. This computational approach is applicable to both thermal collection/conversion processes and photovoltaics (PV). Although sun charts are widely used, there are situations where charts are inadequate and precise computations are preferred. For example, consider fixed PV modules atop residential or industrial buildings in which the value of the electricity varies with date and time.