STUDY THE EFFECT OF DUST DEPOSITION ON SOLAR PHOTOVOLTAIC AND SOLAR RADIATION

Abstract

The aim of this research was study the effect of dust deposition on solar radiation and solar photovoltaic panel. A theoretical calculation was done and experiments were carried out at Mariout Research Station, ElAmria –AlexandriaDesert Research Center. To study the effect of dust deposition two square plates of glass (20x20 cm) and three pyrnometers were used, the first plate (the control) was cleaned daily and the other was used to determine the solar radiation. The period of the experiment is 175 days from 14 march to 26 August 2017. From the experiments; the dust deposition reduces the amount of solar radiation which is falling on the solar panel and creates shadow effect. With the passage of time the density of dust on the panel increases. And this reduces the electric power of the solar panel,. From the data, there was power reduction up to 51.12 %. The efficiency of the solar photovoltaic panel system was reduced from 15.9 to 7.88 % for clean and unclean modules respectively. The total correction solar radiations for the experimental period are 37.4 and 18.28 (kW.h/m) for clean and unclean modules respectively. The unclean module with dust deposition, showed total output power (24.88%) less than the clean module for the period of 25 weeks. Keyword: Efficiency of solar photovoltaic panel, Efficiency reduction. INTRODUCTION gypt is in advantageous position with solar energy. In 1991, solar atlas for Egypt was issued indicating that it enjoys 2900-3200 hours of sunshine annually with annual direct normal energy density 1970-3200 kWh/m, Energy is a major drive of modern economic development .Comsan. (2010). Hassan, et al (2005) Cement dust is considered the main source of pollution; this dust is often present in the atmosphere in the Helwan area and is shown to reduce both the short circuit current and the open circuit voltage when deposited onto the surface of photovoltaic cells. * Agric. Eng. Res. Inst. (AEnRI), Giza. ** Mariout Research Station, D.R.C. E Misr J. Ag. Eng., 35 (4): 1397 1408 BIOLOGICAL ENGINEERING Misr J. Ag. Eng., October 2018 1398 The rate of decrease in these parameters depends mainly on the rate of dust deposition. The decrease in efficiency for polycrystalline silicon solar cells (Poly-Si) 66% after six months without panel cleaning. The decrease in efficiency for Poly-Si is 9% due to the suspended particles with panel cleaning. Chaichan, et al (2015) the obtained results indicate that the air pollution may deteriorate the PV cell performance, even with a short period of two months of the cells’ outdoor exposure without cleaning. The polluted PV cells produced power reduced to approximately 12% compared to the clean cell. While the naturally cleaned cell lost about 8% compared to the clean cell. The maximum power/week increased for the cleaned cell, compared to the polluted and naturally cleaned cells. The collected pollutants inspections clarified high rates of hydrocarbon particulate matters that resulted from cars exhausts. Zorrilla-Casanova J. et al (2011) the mean of the daily energy loss along a year caused by dust deposited on the surface of the PV module is around 4.4%. In long periods without rain, daily energy losses can be higher than 20%. In addition, the irradiance losses are not constant throughout the day and are strongly dependent on the sunlight incident angle and the ratio between diffuse and direct radiations. When studied as a function of solar time, the irradiance losses are symmetric with respect noon, where they reach the minimum value. We also propose a simple theoretical model that, taking into account the percentage of dirty surface and the diffuse/direct radiation ratio, accounts for the qualitative behavior of the irradiance losses during the day. Mohamed A. O., and A. Hasan (2012) this paper investigated a framework of weekly cleaning on PV modules array throughout the period from February to May. The results indicated a significant gradual decrease of power, so frequent weekly water washing maintaining performance losses between (2 2.5%). It is important feature of water washing on the modules surfaces deemed more reliable to recover power loss. Samadhiya A. and Ruchi P. (2016) Solar irradiance has the greatest impact on the power output of a PV system. Beyond irradiance, weather conditions such as ambient temperature along with several other factors (e.g. angle of incidence (AOI), dust, etc. may also affect a module’s or an array’s power output and energy production. To this end, module temperature is influenced by the ambient temperature, cloud patterns and wind speed, while the rate of temperature BIOLOGICAL ENGINEERING Misr J. Ag. Eng., October 2018 1399 change depends also on the PV material and position of the frame. Grubišić-Čabo F. et al., (2016) Shown that active water cooling is the best choice when increasing electrical efficiency is the main goal. Therefore, research aim in the future should be implementation of effective active water cooling of PV panel. Additional solar panel at the water outlet can be proposed to increase water outlet temperature, thus increasing overall efficiency. For reducing pumping costs, front surface cooling is proposed as more economical solution, especially in hot climate conditions. One obvious drawback of front side cooling could be water evaporation, which would require continuous replenishment of evaporated water. Sulaiman S. A. et al., (2011) the effect of presence of dust was studied using artificial dust (mud and talcum) under a constant irradiance conducted in an indoor lab. Dust has an effect on the performance of solar PV panel. The reduction in the peak power generated can be up to 18%. It was also shown that under greater irradiation, the effect of dust became slightly reduced but not negligible. In the study, it was also shown that the differences between the results obtained by using mud and talcum were generally small; i.e. about 6%. Hence, in practice, dust must be removed from the surface of solar PV panel in order to ensure highest performance, given the fact that it is still a costly form of energy source and the short lifespan it has. It was found from the study that the accumulated dust on the surface of photovoltaic solar panel can reduce the system’s efficiency by up to 50%. Mekhilef S. et al., (2012) mentioned that dust deposition and settlement on the surface of PV cells can drop the efficiency. Likewise almost always humidity causes degradation in solar cell efficiency. By increased wind velocity more heat can be removed from the PV cell surface. In the same vein, higher air velocity lowers the relative humidity of the atmospheric air in the surroundings which in turn leads to better efficiency. On the contrary, wind lifts dust and scatters it in the environment resulting in shading and poor performance of PV cells. MATERIAL AND METHODS