Electronic Implementation of Sun Algorithm

Abstract

Abstract Implementation of Solar Position Algorithm (SPA) on an electronic platform is presented. The system consists of a microcontroller and a real time clock. Solar angles according to the SPA were calculated on a computer for 5 years (for each minute). The calculated solar angles indexed according to the time and downloaded to secure digital (SD) through the microcontroller based SD card read/write system. Solar angles for any given time can be retrieved by providing the time index to the look up table recorded in the SD card. 5 MB of space is required to store such a data set for one year. The performance of this system was evaluated by interfacing to a manual sun tracking system of a parabolic trough solar concentrator. It was found to be that the maximum variation of the focal line is 1.5 cm and it is within the full acceptance angle of 3.8º