Evaluation of power output for fixed and two-axis tracking PVarrays

This study compares the performance of two PVmodules, one fixed and the other fitted with a two-axis tracking system which enables the PVcollector to move and be controlled to follow the Sun's radiation. A computer unit was employed to monitor the solar radiation exposure of both systems and to control the movement of the solar tracking PVmodule. Throughout the day, the results obtained from the fixed and tracked systems were collected on a DAQ card installed on an online computer. The two motors of the tracking system were connected to output from the computer that was used to follow the sun. The movement of the two-axis tracking PVmodule was compared to mathematical calculations of the sun's position from sunrise to sunset. The amount of solar radiation received on the surface of the module and hence its output power varied according to the time and the place where the experimental system was mounted. Overall, it was found that the daily output power of the tracking module was 13-15% higher than the fixed module. (C) 2011 Elsevier Ltd. All rights reserved.