A simple formula for estimating the optimum tilt angles of photovoltaic panels

This paper presents a new approach to computing the optimal tilt angle for photovoltaic (PV) panels. The influence of cloudy conditions on the tilt angle is explored. It is demonstrated that more energy can be extracted from the PV system in cloudy conditions when the tilt angle of the panel is decreased compared to when the panel is aimed to be facing directly normal to the sun. Validation for fixed tilt, south-facing panels and for 2-axis tracking panels is presented by numerical simulations.