Degradation and longevity of solar photovoltaic modules—An analysis of recent field studies in Ghana

Abstract

Solar photovoltaic (PV) technology has attracted an enormous amount of attention and investment in recent years—translating to record deployment levels. This is due to in part to its potential role as a cleaner energy source in the emissions-constrained development agenda that is currently being pursued at both global and national levels. Solar PV has also been propelled to the forefront of today's menu of technological options by virtue of its attributes such as scalability, fast deployment lead times, and low operating cost. Substantial investments are needed in the coming years in order to accomplish climate targets and other goals set by various countries and regional/subregional blocs. In support of informed investment decision-making and ultimately, improved outcomes of solar PV projects, there has been an uptick in studies on operational performance of fielded PV systems across the globe. These studies are, however, geographically unbalanced, and there is the need for data from underrepresented regions. This paper presents a synthesis of results obtained from recent seminal field studies on PV module performance degradation in Ghana. The studies altogether analyzed sixty-five (65) modules (mono- and polycrystalline silicon) from twenty-nine (29) installations across the country (1118 module-years). The field-aged modules were characterized in situ using current-voltage (I-V) curves, visual inspection checklists, and thermal imaging. Annual module performance degradation rates (peak power) of 0.8%-7%, 0.55%-2.07%, and 1.1%-2.4% were found for modules located in various climate subcategorizations.