Soiling losses of utility-scale PV systems in hot-dry desert climates: Results from four 4–16 years old power plants

The purpose of this study is to determine the soiling losses in a hot-dry desert climatic condition. The results obtained highlight the soiling losses in four power plants with two different surroundings (urban and rural) and three different installation types (ground mount - fixed tilt, 1-axis tracking and rooftop - fixed tilt). The data obtained from this study can be used in the energy estimation models and to determine if cleaning is an economically viable option for the power plant owners of these locations. In this study four PV power plants aged between 4 and 16 years have been investigated and the key results obtained in these four sites are: Site 3 (Glendale, Arizona) - rural, 1-axis tracking, 12 years, 6.9% soiling loss; Site 4b (Mesa, Arizona) - urban, horizontal tilt (ground), 16 years, 11.1% soiling loss; Site 4c (Mesa, Arizona) - urban, 1-axis tracking, 4 years, 5.5% soiling loss; Site 6 (Tempe, Arizona) - urban, 5o fixed tilt (rooftop), 8 years, 3.8% soiling loss.