Performance Analysis of Rooftop Solar Systems in Urban vs Coastal Areas: A Comparative Study of Bengaluru and Honnavar

Environmental parameters, especially global solar irradiance and ambient temperature, are considered to be the main factors that control the performance of the rooftop solar photovoltaic (PV) systems. The intensity of solar irradiance is a defining factor of the amount of incident energy that can be converted into electricity via photovoltaic methods, whereas temperature has a direct dependence on the module efficiency and electrical output properties as reported in the classical theory of solar engineering 1. Several experimental and analytical works have proven that the efficiency of PV modules declines linearly with cell temperature, therefore, affecting the actual energy output 2. As a result, the climatic variability between the urban areas and the coastal areas can largely change the functionality of the photovoltaic systems and their long-term energy production prospects. This paper is a comparative performance evaluation of rooftop solar PV systems in Bengaluru an urban inland metropolitan region and Honnavar an coastal region of Karnataka, India. The aforementioned NASA POWER (Prediction Of Worldwide Energy Resources) dataset 3 that is commonly used in renewable energy resources evaluation and viability was used to get daily meteorological data of the year 2023 including Global Horizontal Irradiance (GHI) and the average temperature of the air at two meters (T2M). Relying on a deterministic photovoltaic performance model that can be validated through the known principle of PV conversion 1 and with corrections on efficiency depending on temperature as reported in other studies 2, the study assesses both spatial and seasonal changes in the availability of solar resources. Monthly patterns, yearly averages of irradiance and projected photovoltaic energy production were calculated to measure the variations in the performance of the chosen urban and coastal sites. The findings show that there are quantifiable differences in the irradiance and temperature patterns in Bengaluru and Honnavar and, as such, there is a difference in the theoretical annual energy yield. Although it can be seen that the coastal area has slightly higher accessibility to solar resources in some months, the overall annual energy yield is slightly higher in Bengaluru due to lower efficiency losses from urban climatic moderation. The results highlight the need to carry out site-based environmental analysis of maximized rooftop solar implementation and policy development in fast-growing renewable energy market like India.