EFFECTS OF DUST ON THE PERFORMANCE OF PV PANELS

Accumulation of dust from the outdoor environment on the panels of solar photovoltaic (PV) system is natural. There were studies that showed that the accumulated dust can reduce the performance of solar panels, but the results were not clearly quantified. The objective of this research was to study the effects of dust accumulation on the performance of solar PV panels. Experiments were conducted using dust particles on solar panels with a constant-power light source, to determine the resulting electrical power generated and efficiency. 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%. Keywords—Dust, Photovoltaic, Solar Energy. I. INTRODUCTION Solar photovoltaic (PV) system uses solar cells to convert energy from sun radiation into electricity. The system is made up by one or more panels, a battery, a charge control and the load. Solar PV panels are normally mounted on roofs and wired into a building by an inverter, which converts the direct current energy received from solar panels into alternating current. There are many types of solar PV cells available, which are mainly monocrystalline silicon cells, multi crystalline silicon cells, thick film silicon, and amorphous silicon. The application of solar energy has become wider, with the solar photovoltaic industry's combined global revenue of US$37 billion in 2008 (1). In Malaysia, the government has recently been promoting the use of renewable energy due to several driving factors, such as the growing imports of oil and unutilized resources of renewable sources, increasing oil prices, and the environmental awareness. In the Tenth Malaysia Plan, it was reported that the nation attracted investments in solar PV manufacturing that was worth RM9.8 billion or about 20% of investments in the electrical and electronics industries (2). By 2015, the renewable energy capacity is expected to expand to 985 MW, which contributes 5.5 % to Malaysia's total electricity generation mix. Located in the equatorial region, Malaysia has an average solar irradiation of 4500 kWh per square meter (3), and thus making it an ideal place for large scale solar power installations. Considering that the country gets an average of 4.5 to 8 hours of sunshine every day, there is huge potential for high solar power generation. At present, the number of solar PV applications in Malaysia is still low. It is generally restricted to rural electrification, street and garden lighting, and telecommunications. The first centralized solar power station was first built in year 2003, in a remote village, Kampung Denai in Rompin on the eastern coast of Peninsular Malaysia (3). In a recent development, the Tenaga Nasional Bhd (TNB) who is Malaysia's primary electrical power provider launched the development Malaysia's first solar power plant in Putrajaya (4). At an approximate cost of RM60 million or US$4 million per megawatt, the project signifies a major step in harnessing the use of renewable energy in the country. The project would be expected to enable the operator to understand the system well before embarking into development of plants of bigger scale. A drop in the efficiency of a solar PV panel throughout its life cycle is not desired, since the capital cost for the system is quite high. PV cells can normally last for about 25 years, and it takes approximately up to six years (5) for the solar PV module to generate the equivalent amount of energy consumed in its manufacturing processes. One of the contributing factors in the drop of efficiency of solar PV panels in Malaysia as well as in other country is the accumulated dust on the panel. The nature of the problem may vary by geographical locations. Hottel and Woertz (6) were amongst the pioneers investigating the impact of dust on solar systems. They recorded a maximum degradation in collector performance of 4.7%, with an average loss in incident solar radiation being less than 1%. In a study by Salim et al. (7) into dust accumulation on a solar-village PV system near Riyadh indicated a 32% reduction in performance after eight months. Wakim (8) indicated a reduction in PV power by 17% due to sand accumulation on panels in Kuwait city after six days. Furthermore the study also indicated that the influence of dust on PV performance would be higher in spring and summer than in autumn and winter. An experiment to investigate the effect of aeolian dust deposition on photovoltaic solar cells by Dirk Goosen et. al (9) showed that the deposition of fine aeolian dust particles on the glazing of PV cells significantly affected the performance of such cells. This experiment was conducted to investigate the effect of wind velocity and airborne dust concentration on the drop of PV cell performance caused by dust accumulation. Shaharin A. Sulaiman, Haizatul H. Hussain, Nik Siti H. Nik Leh, and Mohd S. I. Razali