Comparative Analysis of Sunshine Models for Estimation of Monthly Global Solar Radiation at Bhopal, India

A key hurdle to properly using solar energy in India has been found as a lack of accurate solar data and an erroneous calculation of the availability of solar radiation at a location. This paper presents the analysis and estimation of the monthly average global solar irradiation for the geographical location of Bhopal, India, situated at 23.16° N and 77.36° E using different regression models. The models are based on the ratio of monthly average daily global solar radiation (H) to the extraterrestrial radiation (H0). Each categorized model is examined, verified, and compared separately. The objective of this study is to estimate the monthly average daily global solar radiation for Bhopal, India, using regression models and to validate these models by comparing the results with data from the Ministry of New and Renewable Energy (MNRE) using Python (SolarPy) and Microsoft Excel Advanced. It was evident from the study that the Angstrom–Prescott model outperforms the other linear models in terms of accuracy. Akinoglu, Ogleman, and Armstrong–Prescott models are suggested for assessing the GSR for the Bhopal region while taking into account all the considerations. The relevant model discussed in this paper may be used to estimate solar radiation relatively accurately for an area of Bhopal and the surrounding area, as well as possibly for any locations with a comparable climate. Further this study would help in selection and designing of adequate solar photovoltaic and thermal technologies for the climatic conditions of Bhopal.