Affiliations: Department of Civil Engineering, Amity University Uttar Pradesh, Noida – 201313, India
| Centre for Energy Studies, Indian Institute of Technology, Hauz-Khas, New Delhi – 110016, India
Abstract: Solar photovoltaic panels are very widely used these days across the country. Their usage is also being encouraged by the central government and there are many subsidies in place as well. The tilt angle of the solar photovoltaic panel with the horizontal along with module orientation determines the transformation of energy into electricity. The optimum tilt angle for solar photovoltaic panels is considered for incident annual solar energy, this angle is usually kept unchanged for the year-round cycle. In this research work, we examine the optimum tilt angles of panels for the incident energy over panels on an annual and seasonal basis in combination with the shading effect of these panels over rooftops of Delhi (latitude 28.7° N), Nagpur (latitude 21.15° N) and Ahmedabad (latitude 23.02° N). Solar radiation data for the investigation purpose has been classified under 3 seasons, i.e., summer (May, June, July, August), winter (November, December, January, February) and equinoxes (March, April, September, October). It is observed that when panels are arranged facing down south and adjusted seasonally for optimum tilt angle; on an annual basis, they generate higher electrical energy and, in the summer, cast a larger shadow; in the winter, cast a smaller shadow as compared to panels which have fixed tilt throughout the year. This arrangement helps in reducing the solar heat flux via the roof in summer and increasing it in winter, thus, favourably affecting air conditioning load levelling in the structure.
Keywords: Solar photo voltaic systems, solar radiation, tilt angles, irradiance, shadow length, heat flux, load levelling in buildings, latitude
