An Automated Solar Photovoltaic Biaxial Tracking System: SolT2A

This paper describes a prototype product code-named SolT2A. It is a system that automatically tracks the sun as it traverses the hemispherical sky vault. The system has been comprehensively used in photovoltaic (PV) satellite systems and is an option for terrestrial applications. For earthbound systems, locations near the Equator experience the crossing of solar altitude across the zenith daily and a reversal of the azimuth over a year. Consequently, static PV systems do not produce maximum generation. Thus SolT2A has been designed and built to address this problem. The system has a four-point solar irradiance sensors and compares their intensity levels. The differentials are analysed and processed by a controller before and then sent to a set of DC motors. Thus SolT2A is a self-correcting system that ensures maximum irradiance captured by the PV arrays at all times, thus ensuring maximum PV generation. Based on field data, the open circuit voltage produced by the SolT2A tracking system is up to 82% better than from static systems The over all increase in open circuit voltage production is between 15 to 20% daily. Further developmental work includes optimising power consumption of the tracking and cost benefit analysis.