Robust Affordable Outdoor Technique for Testing and Characterizing Photovoltaic Modules
Photovoltaic (PV) modules undergo several types of quality assurance procedures before being certified for the market place. Hence, the quality assurance techniques for PV modules are fairly well established and very costly, with maximum power point tracers, reference modules, and solar simulators employed. Tests include mechanical testing for structural rigidity and to ensure durability under severe weather conditions such as hail storms. Various forms of functionality tests (e.g. optical, electrical and electronic testing are also done). As solar PV technology gets more popular in developing countries, the need has arisen for new standards, systems and procedures that adequately reflect the uniqueness of the economic realities of this region. The objective of this research centers on the electro-testing of PV modules. The goal was to investigate an outdoor technique developed to test several photovoltaic modules for equality of mean energy production, subsequently rendering insignificant such variables as: the variability in atmospheric conditions, irradiation, module variability, time of day, solar altitude, and other meteorological factors. The experimental procedure involved simultaneously exposing three statistically equivalent silicon modules to the outdoors for several days and collecting data on module current-voltage parameters as well as meteorological factors. A mixed effects design, utilizing module as a random factor, cloud cover as a fixed factor, and the meteorological parameters as co-variates was used to analyze the data. Uncertainty, sensitivity and economic analyses conducted testified to the robustness and affordability of this procedure. The results were encouraging and confirmed the validity of this technique.
Journal of Arts Science and Technology, Vol 6, 2013, 83-100.