Performance analysis of MW-scale grid connected rooftop and ground-mounted solar power plants installed in Assam, India

Abstract

Solar energy-based electricity generation has become an essential component of sustainable development and meeting the growing demand for energy. A study is conducted to compare the performance of rooftop and ground-mounted solar power plants installed in Assam, India. The study found that ground-mounted plants generated an average of 3.41 kWh per kWp of energy per day, while rooftop plants generated 2.89 kWh per kWp. The study also observed that rooftop solar power plants had non-operating days due to inverter faults, grid failures, and poor weather conditions, which were 1.1 and 0.95 days, respectively. The capacity factors were 14.2 % and 11.4 %, while the performance ratios were 77.8 % and 70.1 % for ground-mounted and rooftop plants, respectively. The average system efficiency of ground-mounted plants and rooftop plants is 12.59 ± 0.26 % and 11.88 ± 0.11 %, respectively. The study used the Weibull distribution function to describe the daily normalized energy generation frequency curve, which revealed a peak probability of 0.38 at a daily normalized energy generation of 2.9 kWh per kWp for rooftop plant and 0.34 at a daily normalized energy generation of 3.4 kWh per kWp for ground-mounted plant. The installation of a solar power plant has resulted in an average reduction of Rs. 43.7 lakhs per year in the University's electricity bill. This study demonstrates the successful operation of rooftop solar power plants, which not only reduces the electricity expenses of organizations but also has a positive impact on sustainability.