Impact of the desert climate on the degradation of photovoltaic modules characteristics: a case study

In this paper, an investigation study has been carried out to evaluate the photovoltaic module degradation, in a desert area of Algeria. In this view, a set of PV modules have been put into tests and assessment for more than 11 years. These modules were assembled into three PV generators composed of monocrystalline (mc-Si) and polycrystalline (pc-Si) PV modules. The I–V curve tracer, calibrated reference m-Si solar cell and Pt1000 temperature sensor tools were used to collect the data. Three degradation modes were examined namely: (i) the visual inspection characterized mainly by a discoloration of PV modules, (ii) I–V degradation characterized by an increase in the series resistance which corresponds to electrical losses in conductors and (iii) the degradation rate (DR) assessment. The main parameters affecting on PV system performance are the high temperatures and sandstorms that characterize desert regions. The results indicated that for monocrystalline and polycrystalline PV modules, the power degradation rates were 1.53% and 0.37% per year, respectively. This degradation rate was found to be 2.36% per year for modules with broken back-sheet and corroded junction box. The production situation of examined PV systems shown a decrease of about 9%, 13%, and 6.8% for PVG1, PVG2, and PVG3, respectively, throughout the operation period. In addition, cell discoloration was observed as the predominant mode of degradation mechanism in desert climatic conditions.