In recent years, photovoltaic (PV)- power plant has increased markedly. The dust-caused loss of a 20 MW(p) PV power plant, located in the Baicheng area, was analyzed. The power generation data show that dust-caused power-loss has a linear dependency with dust deposition. A cleanliness management model is used to find the optimal cleaning-cycle to produce maximum output-power. The results show that, when the average light intensity is 260W/m², the 500kW array produces the maximum economic output per unit time, using mechanical cleaning and a cleaning cycle of 2.9 d, so as the 20 MW(p) PV power plant. For a 20MW solar PV power plant, the yearly income can increase RMB 1.32 million by selecting the optimized cleaning cycle.

PV modules, dust deposition, maximum output cleaning -cycle, economic analysis