Effects of Dust Deposition on the Surface Temperature and Performance of Photovoltaic Modules

As energy demands grow, renewable energy sources are gaining popularity as a solution [1]. To promote the use of renewable energy, governments worldwide are calling for policy changes [2], [3], [4]. As a result, the global installed renewable energy capacity is more than double that of 2011 by 2022 [5]. The most practical renewable energy source is solar power. It is also easily available, straightforward to install, and reasonably priced [6], [7]. Solar radiation transmits around 1.8 × 10$^{11}$ MW of energy to the Earth's surface per second [8]. This number only makes up a small portion of the energy used worldwide [9]. Adinoyi and Said [10] found that photovoltaic modules tilted at 26° in eastern Saudi Arabia showed a 50% decrease in power output after six months of soiling. Furthermore, Benghanem et al. [11] found that modules tilted at 25° in the non-coastal region of western Saudi Arabia showed a 28% decline over two months. Photovoltaic module efficiency decreased by 37.6%, 14.1%, and 10.9% for 0°, 25°, and 45°, respectively, after 14 days of exposure to outdoor sunlight in Kuwait [12], [13], [14], [15], [16], [17].

Mustafa et al. [18] investigated the effectiveness of the light spectrum from 10, 15, and 20 W light-emitting diode bulbs as a power source for producing electricity in a small monocrystalline solar module. Before the light spectrum was transported to the photovoltaic cell's surface, it was compared with and without a Fresnel lens. According to test results, photovoltaic cells exhibited different conversion efficiencies under the two configurations: an efficiency of 3.77% was obtained with the Fresnel lens at a 15 W lamp power, while an efficiency of 4.86% was achieved without the Fresnel lens at a 20 W lamp power.

Mustofa et al. [19] conducted a study to determine the photovoltaic tilt angle for harvesting photon energy from light-emitting diode lamps commonly used in homes or residential buildings. The tested solar panel tilt angles were 0°, 15°, 30°, and 90°, while the lamp position was fixed. The results showed that a 0° tilt produced the highest electrical power from the solar panels. The power output decreased to 16.33, 12.92, and 12.91 W at 15°, 30°, and 90°, respectively. The aim of studying the effect of tilt angle on the performance of solar panels is to understand the relationship between tilt angle and the efficiency of solar panels in converting solar energy into electrical energy. The purpose of the study is to use light bulbs to generate electricity and thus take advantage of the light energy emitted by the bulbs to convert it into electrical energy.

The experimental setup consisted of a 100-W polycrystalline photovoltaic module, a light-emitting diode lamp array, and the associated measurement instruments. The photovoltaic module was positioned in front of the light-emitting diode lamp array, which provided five irradiance levels of 100, 200, 300, 400, and 500 W/m$^2$. Figure 1 shows the entire experimental setup with all its components. The type of lamp used was a light-emitting diode, and the distance between the lamp array and the panels was 50 cm. Table 1 provides an overview of the technical specifications of the solar photovoltaic module and the measurement equipment used in this study.

Solar panels need to be cleaned regularly to ensure they operate at maximum efficiency. Dirt, dust, and other debris that accumulate on the surface of solar panels can reduce their ability to absorb sunlight and generate electricity. Therefore, dust is one of the most important factors affecting the performance of photovoltaic panels. There are many types of dust, such as soil, fertilizer, sand, and others. However, in this study, soil was used as the dust material because it is the most common type of dust found in nature that falls or accumulates on the panels and affects their performance. Four dust deposition densities of soil were used in this study to demonstrate the effect of the thickness and weight of the accumulated soil on performance (25, 50, 75, and 100 g/m$^2$). Figure 2 shows the dust sample used in this study. For dust distribution, a very fine sieve was used to distribute the dust uniformly. Sieves (or “standard sieves”) are a device consisting of a mesh with specific-sized openings used to sort and separate particles according to their size. Sieves allow smaller particles to pass through while retaining larger particles (Figure 3). They are widely used, with opening sizes ranging from several microns to several millimeters. A sieve allows smaller particles to pass through while retaining larger particles and is determined according to specific standards such as ASTM or ISO.

This section discusses the measurement uncertainties of the instruments (Table 2).

Figure 4 illustrates the experimental effects of different dust deposition densities (25, 50, 75, and 100 g/m$^2$) and tilt angles (10°, 20°, 30°, and 45°) on the surface temperature of the photovoltaic panel, compared with a clean panel. As the dust deposition density increased, the panel's surface temperature rose. This is because photovoltaic panels absorb sunlight and convert it into electricity, but only a portion of this light is converted into heat. As dust accumulated, heat absorption increased, thereby increasing the panel surface temperature. The study showed that the temperature at 30° is 10 °C higher than at 20° under 100 g/m$^2$.

Figure 5 illustrates the experimental results of the effect of different dust deposition densities accumulating on the panel surface (25, 50, 75, 100 g/m$^2$) at different angles (10°, 20°, 30°, 45°) on the maximum power output. As the dust deposition density increased, the panel's power output decreased. This is due to the reduced amount of light reaching the photovoltaic cells, leading to lower electrical output. The results showed that power increased as the panel tilt angle increased by 10% to 40% due to the resulting perpendicularity between the incident light rays and the solar panel, thus reducing radiation wasted due to angular deviation. The results also indicated that increasing the dust deposition density led to a power decrease of 30% to 50%.

The dust deposition density on photovoltaic panels was inversely proportional to the energy output. As the accumulated dust (or dust deposition density) increased, the panel's electrical efficiency and power generation decreased linearly, leading to total energy losses that ranged from 20% to more than 50%. The increased dust deposition density on photovoltaic panels significantly affected the efficiency of the panels in converting solar energy into electricity. Figure 6 illustrates the effect of different dust deposition densities (25, 50, 75, 100 g/m$^2$) and different angles (10°, 20°, 30°, 45°) on the conversion efficiency of the photovoltaic module. The greater the dust deposition density, the lower the conversion efficiency. This reduction occurs because dust blocks part of the incident light. The thicker the dust on the panels, the more light is blocked, thus reducing the amount of energy generated, which in turn reduces the conversion efficiency due to the direct relationship between power and efficiency. At lower densities (25 g/m$^2$), an efficiency drop of around 33% was observed, and at heavier accumulations ranging from 50 g/m$^2$ to 100 g/m$^2$, power losses exceeded 40% and reached approximately 50%, depending on the type of dust and local climate.

Table 3 presents some studies published in the scientific literature and compares them with the present study. Previous studies have extensively investigated the effects of dust deposition on the performance of photovoltaic modules. However, the literature review indicated several factors affecting the performance of the photovoltaic system and power generation, such as location, dust characteristics, and pollution in the area.

This study investigated the effects of panel tilt angle, dust deposition density, and operating temperature on the electrical performance of photovoltaic modules using light bulbs. The influences of these factors on the current, voltage, power, and efficiency were experimentally evaluated. The main findings are summarized as follows:

\(\bullet\) It is possible to generate energy by utilizing the light of the lamps as solar radiation.

\(\bullet\) The optimal angle for the experiment concluded for this study is 39°.

\(\bullet\) High panel surface temperature (such as solar panels) can significantly affect the electrical performance of systems such as current, voltage, and power.

\(\bullet\) In general, high temperature leads to a decrease in current. As the temperature increases, the internal resistance of the plate may increase, resulting in a decrease in the generated current.

\(\bullet\) Voltage is more sensitive to temperature. As temperature increases, the voltage of the solar cell or panel decreases substantially.

\(\bullet\) Since voltage tends to decrease with increasing temperature and current may also be affected, the output power generally decreases with increasing temperature.

\(\bullet\) Sustainable development and environmental conservation can be supported through energy generation from alternative sources such as lamps.

\(\bullet\) At lower densities (25 g/m$^2$), an efficiency drop of around 33% is expected, and at heavier accumulations ranging from 50 g/m$^2$ to 100 g/m$^2$, power losses exceed 40% and reach approximately 50%, depending on the type of dust and local climate.

\(\bullet\) The results also indicate that increasing the dust deposition density can lead to a power decrease of 30% to 50%.

\(\bullet\) The study shows that at a dust deposition density of 100 g/m$^2$, the panel temperature at 30° was 10 °C higher than that at 20°.