Study for the Irradiance Attenuation on the Cover of Solar Collectors Due To Humidity and Dustfall in Southern Taiwan

Abstract: Air quality becomes worse in southern Taiwan partly due to two factors; humidity and falling dust, which affect the solar collector performance. Under the indoor experiments in this study, the humidity in the chamber and dustfall on sample glasses are used as parameters, and the temperature and irradiance on the observation plane are recorded and analyzed. The humidity chamber is used to simulate relative humidity in the air and sample glasses representing the cover of solar collectors are used to collect falling dust outdoors for four months. Therefore, we can obtain irradiation attenuations due to effects of humidity or dustfall quantity. Besides, the numerical diffuse fractions, simulating the irradiance reduction due to humidity or dustfall quantity, are tuned in numerical simulations to fit the experimental data for further design purposes. Correlations for the relation of irradiation attenuations versus relative humidity and dustfall quantity respectively are proposed based on experimental data.