The simplest method for the accurate determination of noon

Abstract

In this paper, we present the simplest possible method for the precise determination of solar noon and mean solar time, based on the value of the equation of time corresponding to a predetermined instant for the observer, constant throughout the year. This represents a revolutionary simplification of the appendix of the universally known SPA (Solar Position Algorithm, NREL) regarding solar noon. Given that the proposed simple method does not entail a significant loss of precision, it is especially useful for university students or postgraduate students in photovoltaic/solar thermal energy or developers who wish to create their own software for analysis or research. In addition, an interpolative procedure is presented to further enhance the precision of the method, although such improvement will not be necessary in the majority of cases.