Optimal Tilt Angle and Spacing for Rooftop Solar PV System in Hot Humid Climate-A Case Study
Abstract
Solar energy received by a PV surface depends on the incidence angle of the sun rays on it. The solar angle changes with time of the day, day of the year and installed location of the PV arrays. The PV modules of the array must be placed perpendicular to the sun so as to receive maximum irradiance. In absence of such placement, the PV system may exhibits mediocre performance. So, it is therefore required to install the PV modules at an optimum tilt. The performance of PV array is also susceptible to shadow problems as well. In this paper, the installation aspects of PV systems such as positioning of PV arrays with respect to tilt angle and separation criteria of their rows to mitigate the horizontal shadow effect is presented. Whenever, the PV arrays are installed, it is to be fixed at an appropriate tilt angle so as to receive maximum irradiance. The separation of the rows of arrays was done so as to make it shadow free. The optimum tilt angle and spacing was found out and validated by a prototype site installation for a 11.2 kWp solar photovoltaic system at SOA, Bhubaneswar, India and the monthly, seasonally and annually optimum tilts, solar flux gain and energy yield are found out for this location. The maximum solar flux gain of 32.97% is found in the month of December having GSR of 4.72 kWh/m2/day at an optimum tilt of 400 and minimum solar flux gain is in the month of July, August and September. The shading is also increased in summer (May, June, July, and August) by the tilt adjustment which causes cooling.
