A Cost-Effective Active Single Axis Solar Tracking Mechanism Based on Weight Imbalance Principle

Solar trackers are rising in popularity; they benefit a wide range of applications since distributed solar energy generation can reduce electricity costs and support energy independence. In this paper, a simple solar tracking system is introduced. The system is a package unit that can be mounted on any solar panel. The system consists of an electrical motor connected directly to a sliding mass on a linear bearing. The electrical motor is controlled to slide the weight along the shafts in controlled steps. As a result, the photovoltaic panels are rotated automatically under the effect of controlled weight unbalance in fine angle increments to track solar trajectory without the need for traditional complex or costly mechanisms. Two light dependent resistors (LDR) sensors, mounted onto the surface of the solar photovoltaic panel, are exposed to solar irradiance and used to feed signals to a controller. A model of the solar tracking system is developed using ordinary differential equations, and numerically solved by MATLAB/Simulink™. The power consumption and tracking strategy of the proposed tracking system are estimated under realistic operating conditions (e.g. wind and brakes), and the power consumption is compared to the power generated by the photovoltaic panels. Optimum values for the sliding mass are suggested. Two photovoltaic modules are used to calculate the output parameters of the proposed tracking mechanism.