A comparative analysis of long-term field test of monocrystalline and polycrystalline PV power generation in semi-arid climate conditions

Two different, commercially available photovoltaic modules, monocrystalline and polycrystalline, have been monitored outdoors in the semi-arid area of Iran, over a complete year. The values of power output, specific energy yield, normalized power output, efficiency and performance ratio of each module have been analyzed and linked to the climatic characteristics of the site. The result indicates that despite the similar behavior of both PV modules with instantaneous irradiance, the monthly behavior of the modules is different, which is due to different light absorbing and thermal characteristics of each panel. The monthly average module efficiency of monocrystalline module has a gradual decreasing trend in the months with a higher ambient temperature, while polycrystalline module shows an inverse behavior. The results of monthly performance ratio have also shown that the performance of monocrystalline module decreases with increasing monthly ambient temperature. Monitoring the gross performance of both PV modules shows that the monocrystalline module performed better both regarding maximum efficiency and overall specific energy yield, and was found to be more efficient at this site. This work offers are also useful as a comparison for investigating the productivity of solar plants in different areas with climatic characteristics similar to the semi-arid region of Iran. (C) 2017 International Energy Initiative. Published by Elsevier Inc. All rights reserved.