Experimental performance comparison of fixed and single-axis subfields in a large-scale outdoor photovoltaic power plant

Abstract

This study analyzes the power production (PP) and energy yield of four 100 kW PV subfields, consisting of monocrystalline and polycrystalline technologies, with fixed and single-axis tracking systems. All subfields are installed at a 30° inclination, close to the region’s optimal angle. Actual performance data were recorded every four minutes in OUED-NECHOU, Ghardaïa, over four experimental days in 2016, each representing a different season. The results indicate that single-axis tracking subfields consistently outperformed fixed systems throughout the diurnal cycle by generating more power and enhancing overall performance. However, on May 1st, the fixed mc-Si and pc-Si subfields reached peak outputs of 95.67 kW and 84.06 kW, respectively, surpassing the motorized subfields, which recorded 88.35 kW and 83.01 kW. Conversely, on July 1st, the single-axis tracking systems achieved their highest daily energy generation, with the mc-Si subfield producing 787.94 kWh/day and the pc-Si single-axis system generating 715.17 kWh/day. Further analysis of mean power output augmentation demonstrated that single-axis tracking subfields consistently outperformed their fixed counterparts, which served as the baseline across all experimental days, with the highest gains observed in east–west tracking systems. On July 1st, the mc-Si tracking system achieved a 19.22% increase over the fixed mc-Si subfield, while the pc-Si tracking subfield exceeded its fixed counterpart by a remarkable gain of 21.44%. Moreover, tracking systems exhibited a clear advantage in maximizing solar energy capture, leading to higher energy production. Finally, the impact of weather conditions, including solar irradiance, temperature, wind speed, and relative humidity, on PV subfield power generation was experimentally analyzed.