An Update on Solar Energy and Sun Tracker Technology with a Dual Axis Sun Tracker Application

This paper presents a brief history and an update on solar energy and Sun tracker technology. Absorption of the Sun light by a photovoltaic solar panel (PV) depends on its position with respect to the Sun. To increase the energy efficiency of a solar array and maximize its output power, its position with respect to the sun must be adjusted daily and seasonally. To increase the received solar power, one traditional approach has been the adjustment of solar array daily and seasonally through solar tracking. Another approach, CPV technology, is the use of cost-efficient concentrating optics that drastically change the cell area with an overall efficiency of about 49%, [2]. In general, there are three major approaches for maximizing the power delivered to a load from a solar array. They are sun tracking, Concentrator Photovoltaic technology, and maximum power point (MPPT) tracking or a combination of both. This paper focuses on the design of a sun tracker system using four LDRs sensors and electronic control circuits. Two LDR sensors adjust the array inclination angle during the day (East-West) while the other two LDR sensors adjust the tilt angle of the solar array seasonally (North- South). The solar array assembly uses two actuators (dual-axis) to track the sun daily and seasonally. MPPT algorithm is employed to guarantee the maximum power transferred from the solar array to a load. The DC output voltage of the solar array is converted to an AC voltage through an inverter. To enhance the overall performance of the system, a PID controller was included in the feedback loop. MATLAB software is used to simulate the composite system. Finally, the designed circuits are implemented in laboratory and the overall performance of the composite system are evaluated.