Long-term performance of grid-integrated solar photovoltaic system on institutional buildings in tropical wet and dry climates of India - a practical study.

This study presents a long-term performance analysis of a one-mega-watt power grid-connected PV plant installed on the rooftop of GITAM University, Visakhapatnam, Andhra Pradesh, India for 3 years. The 1000 kWp PV plant design, performance analysis, economic feasibility, and greenhouse gas reduction are provided. For 3 consecutive years (2018-2019, 2019-2020 and 2020-2021), the energy yields, performance ratio (PR), capacity utilisation factor (CUF) and efficiency are evaluated. The plant was established in 2018 with a peak power of 1000 kWp. The system feeds the state grid with all of the electricity it produces. The system is continuously monitored and analysed using yield, efficiency and performance parameters for 36 months (September 2018 to August 2021). Solar irradiation data has been collected from the National Renewable Energy Laboratory (NREL) database for these years. The system comprises 3078 PV modules, 23 inverters rating 20 kW/50 kW, a data logger and a Net-metering unit. The annual energy generation of the PV plant recorded during the study period is 1376.29 MWh, 1265.541 MWh and 1115.73 MWh. The annual average performance ratio for the first three consecutive years is observed as 0.68, 0.62 and 0.58, whereas the yearly average capacity factors are 15.5%, 14.11% and 12.72%, respectively. The overall system efficiency of the PV system during the study period is 11.39%. Compared to the country's current conventional thermal power plants, we predict that rooftop PV systems may reduce CO2 emissions by 2145.406 tCO2eq for the base year, based on the electricity produced by this PV plant. The grid-integrated photovoltaic plant in this study is compared to other systems in the literature for performance assessment.

Operating temperature prediction and comparison for rooftop PV arrays in coastal climates of India.

This article predicts the operational temperature of a 1-MWp rooftop photovoltaic (PV) system installed on buildings of GITAM University, Andhra Pradesh, India, using various temperature models. In the process of photovoltaic conversion, the operating temperature plays a key role, where the module efficiency and output power of the PV module are linearly dependent on temperature. Various temperature models are presented in the literature with simplified working formulas to find the module temperature involving environment and PV system parameters. This study adopts four models NOCT (normal operating cell temperature), Fiaman, Scandia and arbitrary mounting model (AMM), to assess the power, module temperature of the photovoltaic plant and identify the best model to suit the present study location. Their precision is evaluated on a seasonal day (winter, summer, monsoon and autumn) from the measured data. It is observed that winter, summer, monsoon and autumn days have hourly average module temperatures of 45.4 °C, 48.1 °C, 48.2 °C and 45.3 °C, respectively. Results show the highest average DC voltage of 231.2 kW on a summer day with an hourly module temperature of 48.1 °C recorded. The slightest error values of 3.71% MBE, 5.8% NRMSE, 1.89% TS and 0.03% WMBE are noted with the arbitrary mounting temperature model. This study is helpful to validate that the AMM model is best suited for PV simulation in coastal regions.