A comparison of photovoltaic sun tracking methods

Solar energy is one of the most sustainable sources of energy that many countries are investing in. Photovoltaic technologies are becoming increasingly popular due to their renewable energy perspective and low environmental impact. However, the efficiency of commercial fixed photovoltaic panels is under 27% as a reduced amount of solar radiation can be captured during the day. Solar tracking systems are gaining ground as they propose to optimize the angle of incidence of the sun's rays on photovoltaic panels to address the low efficiency issue of fixed PV panels. This study compares the different methods of solar tracking systems with single-axis movable PV panels to quantify the increase in energy production versus fixed PV panels. A simple sun tracking method based on the sun-path diagram is compared with more advanced approaches using the incident angle of the sun ray, measured by a sun position sensor. The electric output power produced by the photovoltaic system is also used to track the sun's position with a high degree of accuracy. Additionally, other hybrid strategies combining different sun tracking algorithms are proposed to improve the low PV efficiency during cloudy days. The performance of the solar tracking system is evaluated by measuring the power output of the PV panels in both static and dynamic positions. A test bench of several single-axis movable PV panels is used to compare the performance of the different sun trackers simultaneously, under the same weather conditions. Key parameters such as solar radiation, sun position in the sky and generated output voltage and current are considered to evaluate the effectiveness of the various sun tracking methods. The experimental results demonstrate significant benefits of sun tracking control strategies by improving the efficiency of PV panel systems up to 16%.