Waterless cleaning technique for photovoltaic panels on dual-axis tracker.

Several soiling mitigation solutions and cleaning techniques have been developed to maintain high efficiency of photovoltaic (PV) panels. First of its kind, the investigation of the adaptability of the cleaning systems to solar trackers has been performed. The majority of these systems are dedicated to fixed installations whereas only few systems that can be adapted to solar trackers are presented in the updated cleaning systems background. For this reason, this paper presents an innovative approach which consists of combining trackers with an integrated cleaning system that has been designed. Based on the conducted experimental study, a maximum of 7% in soiling losses has been found for the PV generator of 4 kWp equipped with a dual-axis tracker installed in Rabat-Morocco over almost 1 year. Consequently, a reduced cleaning prototype has been realized and tested to evaluate the energy recovery based on the performed cleaning. The automatic cleaning has presented a similar efficiency with the manual cleaning with a slight difference of 0.95 pp and an increase of energy of 11.5% in the arid region. Through the economic analysis carried out taking into account the gain in energy production, the automatic cleaning cost was 0.14 USD/kWh. It has been found that the cleaning technique based on the telescopic arm would be more effective if the tracker is installed in an arid region where soiling is higher than Rabat. In this case, the payback time of the cleaning solution is faster (8 to 9 years), hence its profitability.