Smarter PV Single Axis Tracking: A Study on Diffused Light Capture

Solar trackers are advantageous for photovoltaic (PV) systems, typically generating more energy than those mounted on fixed racks. However, this is not always the case, when the sun is obscured by clouds, it is often more efficient to position the PV panel in a fixed horizontal position toward the zenith in order to collect the most diffuse irradiance. This study introduces a hybrid single-axis tracking (SAT) algorithm, named Sundelay, which utilizes sky images to determine the optimal moments for switching between sun tracking and a fixed horizontal position. Sundelay is evaluated through simulations conducted in two distinct locations: Albuquerque, New Mexico, and Eugene, Oregon. The simulations leverage a novel dataset comprising minutely recorded <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$180^{\circ }$</tex-math></inline-formula> direct irradiance measurements obtained from a multiplanar irradiance sensor (MPI) and images captured by an all-sky camera. Our findings indicate energy gains of up to 4.3% with a 61% reduction in the movement of the SAT system over a month, while maintaining minimal impact on irradiance and movement during clear sky conditions.