Investigation on Power Generation Valley of Single-Axis Tracking Arrays at a Solar PV Plant in Australia

With the development of the photovoltaic (PV) technology, more large-scale solar PV plants are integrated to the power grid to relieve the traditional coal-based power plants and reduce the carbon emission. Compared with fixed-tilt (FT) arrays, single-axis tracking (SAT) arrays can produce more power yield. In terms of maintenance fee, SAT arrays are also cheaper than that of dual-axis tracking (DAT) arrays. Thus, SAT systems are becoming a cost-effective option for large-scale PV plant constructions. However, in an Australian PV plant, the power generation of SAT arrays exhibits an unusual phenomenon -- “a valley of power generation” during the midday time. This paper aims to provide an insight about this phenomenon through comprehensive theoretical analysis. Three impact factors, i.e., temperature, tilt angle and incidence angle of direct irradiance to the panel are investigated which determine the power generation characteristics of SAT arrays. The findings of this study can provide valuable insights for PV owners/utilities to better understand the SAT operational behaviors and manage the demand response.