Energy Gain between Automatic and Manual Solar Tracking Strategies in Large Scale Solar Photovoltaic System- 12 Cities Comparison

Abstract

The electrical power generation from a solar photovoltaic (PV) system can be maximized by using automatic solar tracker via single-axis or dual-axis solar tracker system. However, such system is more expensive and complex than the fixed solar system. Manual tracker that changes the tilt angle of PV panel on periodical basis is another alternative that can be considered. This paper compares the energy output performance of a grid connected large scale solar (LSS) PV system with the following solar tracking strategies i) automatic single-axis ii) automatic dual-axis iii) manual monthly adjusted tilt angle and iv) manual seasonally adjusted tilt angle. 12 cities worldwide were chosen systematically for this study. The PV mathematical model was developed by using MATLAB software to simulate the energy output of 1 MW LSS PV system in terms of its annual average daily energy output (MWh/day). The results show that the energy output of a single-axis solar tracker PV system is close to the dual-axis tracker system for most cities, especially the one located at 40 degrees latitude and above. Thus, single-axis tracker system is preferred due to less expensive, lower cost operation & maintenance, less complex than the dual-axis tracker. Moreover, the results show that the energy output from manual tracker with monthly optimal tilt angle is greater than seasonally. With energy gain that can reach up to 8% depending on the location's latitude angle as well as the local climatic conditions of each city. Generally, manual trackers are much cheaper, easier, most reliable, and longer lifespan than automatic trackers. Thus, manual tracking with monthly optimum tilt angle can be considered as an alternative solution between the high energy gain, expensive automatic solar tracker system and the low energy gain (relatively), yet cheap fixed panel solar PV system.