Effect of industrial dust deposition on photovoltaic module performance: Experimental measurements in tropical region

A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree on Master’s in Sustainable Energy Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyDust particles accumulation affects photovoltaic module transmittance of photovoltaic solar cell glazing, and thus leading to substantial reduction of conversion efficiency owing to lower irradiance reaching the surface. In this study, the sensitivity of polycrystalline photovoltaic module towards industrial dust deposition was experimentally investigated under the tropical climatic condition of Arusha Region in Tanzania. Dust involved in the study was collected from fertilizer, gypsum, aggregate crusher and coal mines industries. Particle size analysis was done by sieve analysis technique to get different particle size range 20 μm-45 μm, 45 μm – 90 μm and 90 μm- 180 μm. The dust was uniformly distributed over the module with a baby powder bottle which had 100 g capacity with six holes of 0.1 inch diameter size, the holes was covered with sieve mesh in front of it in order to enhance uniform distribution. The experiment was conducted in an outdoor environment whereby two identical polycrystalline modules of rated power 100 W; were mounted at 15o facing north. Each module was connected to digital voltmeter and ammeter, modules current and voltage were monitored by supplying power to a rheostat, the I-V curves measurements were conducted at three different solar irradiances 720 W/m2 , 800 W/m2 and 900 W/m2 ; characteristic electrical parameters were obtained. Results indicate that dust deposition has more effect on short circuit current and does not affect open circuit voltage. Maximum module efficiency loss on polycrystalline photovoltaic module was determined to be 64%, 42%, 30% and 29% for coal, aggregate, gypsum and organic fertilizer dust, respectively. Therefore the coal dust was observed to have higher photovoltaic efficiency loss (64%) compared to all four tested dust samples. It was also demonstrated that photovoltaic module performance deteriorated with temperature rise owing to heat dissipation caused by dust accumulation. In accordance with literature data this study confirmed that efficiency loss on photovoltaic module also depended on the size of the dust particles accumulated on it; small particles reduced more performance efficiency compared with the larger particles. Keywords: Photovoltaic module, Performance efficiency, Dust, Solar irradiance