Qualitative analysis of thin-film CIGS and c-Si technologies in tropical environments

The technological advancement in solar photovoltaic (PV) materials enabled system designers, engineers and end-users to select the best type of system for a given environment. This paper identifies and investigates the key environmental factors that affect the performance of two different PV technologies under the tropical climate; the thin-film copper indium gallium di-selenide (CIGS) and the conventional crystalline silicon (c-Si) systems. The annual Northern Australian climate consists of distinct wet and dry cycles and a cycloneprone environment. The effects of real-world conditions on the panels were investigated experimentally. The measured performance of the PV systems showed a reduction of 19.6% and 9.2% for the maximum energy output and 34% and 22% reduction of the total daily energy production for the CIGS and c-Si systems respectively during the dry season period. The systems managed to regain their optimal efficiencies during the start of the wet season when the first rainfall occurred. This study highlighted the effects of soiling (dust accumulation), fauna droppings, shading and orientation on the PV system efficiencies in a tropical locale were presented. For the Northern Australian climate, CIGS and c-Si PV systems should be washed at least once during the dry season in order to maintain its original efficiencies. This paper concluded that real-world testing of PV technologies is crucial, and should complement the existing laboratory testing to accurately estimate the system's performance and behavior.