The photovoltaic (PV) solar panels are negatively impacted by dust accumulation. The variance in dust density from point to point raises the risk of forming hot spots. Therefore, a prepared PDMS/SiO2 nanocoating was used to reduce the accumulated dust on the PV panels' surface. However, the effectiveness of these coatings is greatly influenced by geographical and climatic factors. Three identical PV modules were installed to run comparable experimental tests simultaneously. The first module is coated with the prepared PDMS/SiO₂ nanocoating, the second is coated with commercial nanocoating, and the third module is uncoated and serves as a reference. The prepared nanocoating was hydrophobic and had a self-cleaning effect. The fill factors for the reference panel (RP), commercial-nanocoated panel (CNP), and prepared-nanocoated panel (PNP), were 0.68, 0.69, and 0.7, respectively. After 40 days of exposure to outdoor conditions, the dust densities on the RP and PNP panels' surfaces were 10 and 4.39 g/m², respectively. Thus, the nanocoated panel's efficiency was found to be higher than that of the reference panel by 30.7%.

The operation and effectiveness of a solar-powered underground water pumping system are affected by many environmental and technical factors. The impact of these factors must be investigated to be considered when developing these systems and to ensure their dependability. This study evaluated the dependability and performance of photovoltaic water pumping system (PVWPS) under real operating conditions by examining the effects of solar irradiance, panels’ temperature, and components' efficiency. From December 2020 to June 2021, experiments were conducted on a 10 hp PVWPS located in Bani Salamah, Al-Qanater-Giza Governorate, Egypt, at latitude 30.3° N, longitude 30.8° E, and 19 m above sea level. The irradiance values reached 755.7, 792.7, and 805.7 W/m²at 12:00 p.m. in December, March, and June, respectively. Furthermore, the irradiance has a significant impact on the pump flow rate, as the amount of pumped water during the day reached 129, 164.1, and 181.8 m³/day, respectively. The panels' temperatures rose to 35.7 °C, 39.9 °C, and 44 °C, respectively. It was observed that when the temperature rises by 1 degree Celsius, efficiency falls by 0.48%. The average efficiency of photovoltaic solar panels reached its highest value in March (13.8%) and its lowest value in December (13%).

Numerous factors, such as dust accumulation and light reflection off photovoltaic (PV) panel surfaces, adversely affect the performance and efficiency of PV solar panels. On PV panels, dust accumulation increases with time. Irradiation losses caused by dust deposition have a negative impact on PV solar panels. Regular cleaning is necessary for PV panel maintenance, but when carried out manually, it is labor-intensive. The hand-cleaning techniques use a lot of water and energy. The automated cleaning methods initially cost a lot of money and need an electrical source to function. As a result, self-cleaning techniques like hydrophobic coatings are popular since they don't require power and don't leave scratches on panels during cleaning. Since the current-voltage curve, the power-voltage curve, and the fill factor are the most indicative factors of the efficiency and performance of photovoltaic panels, the impact of hydrophobic nanocoating and dust on these factors were investigated in the present study. Results showed that the nano coating was hydrophobic and had a self-cleaning effect. After 40 days of exposure to outdoor conditions, the dust densities on reference panel (RP) and prepared nanocoated panel (PNP) before water spraying (self-cleaning) were 10 and 4.30 g/m2, while the dust densities after water spraying(self-cleaning) were 4.80 and 1.12 g/m2, respectively. The I-V curve for a clean reference panel (RP) and a prepared-nanocoated panel (PNP) showed that the short circuit current Isc was 5.69 and 5.82 A, and the open circuit voltage Voc was 20.3 and 20.7 V, respectively. The fill factor for PNP (0.7) was higher than RP (0.68). For dusty panels, the short circuit current Isc was 4.80 and 5.65 A, and the open circuit voltage Voc was 20.0 and 20.2 V, respectively. The fill factor for PNP (0.69) was higher than RP's (0.63). Based on study results, the nano coating has a positive impact on the I-V curve, P-V curve, and fill factor. That’s because of its anti-reflective and self-cleaning effect.

Chickpeas hold significant nutritional and cultural importance, being a rich source of protein, fiber, and essential vitamins and minerals. They are a staple ingredient in various cuisines worldwide. Peeling chickpeas is considered a crucial pre-consumption operation due to the undesirability of peels for some uses. This study aimed to design, test, and evaluate a small chickpea seed peeling machine. The peeling prototype was designed in accordance with the chickpeas’ measured properties; the seeds’ moisture content was determined to be 6.96% (d.b.). The prototype was examined under four different levels of drum revolving speeds (100, 200, 300, and 400 rpm), and three different numbers of brush peeling rows. The prototype was tested with rotors of four, eight, and twelve rows of brushes. The evaluation of the chickpea peeling machine encompassed several parameters, including the machine’s throughput (kg/h), energy consumption (kW), broken seeds percentage (%), unpeeled seeds percentage (%), and peeling efficiency (%). The obtained results revealed that the peeling machine throughput (kg/h) exhibited an upward trend with increases in the rotation speed of the peeling drum. Meanwhile, the throughput decreased as the number of peeling brushes installed on the roller increased. The highest recorded productivity of 71.29 kg/h was achieved under the operational condition of 400 rpm and four peeling brush rows. At the same time, the peeling efficiency increased with the increase in both of peeling drum rotational speed and number of peeling brush rows. The highest peeling efficiency (97.2%) was recorded at the rotational speed of 400 rpm and twelve peeling brush rows. On the other hand, the lowest peeling efficiency (92.85%) was recorded at the lowest drum rotational speed (100 rpm) and number of peeling brush rows (4 rows). In the optimal operational condition, the machines achieved a throughput of 71.29 kg/h, resulting in a peeling cost of 0.001 USD per kilogram. This small-scale chickpea peeling machine is a suitable selection for small and medium producers.

The abundance of solar energy always coexists with the scarcity of other energy sources and clean water, such as in desert areas. Research articles published in peer-reviewed journals that address the design and simulation of water pumping systems using PV SYST software are in short supply. Therefore, this study was conducted to design and simulate a 101.4 kW PV underground water pumping system using PV SYST software, with the aim of supplying a farm facing water and energy resource shortages with the necessary water for agricultural facilities and the farming process. Additionally, by simulating the system for a full year using the PV SYST, gathered information about the system's losses, inappropriate components, and design errors. By addressing these issues before installation, time, effort, and resources can be saved. The effective solar radiation value on the collector plane was 2145 kWh/m2, whereas the nominal power was 461.46 kWh/m2. This shows the efficiency of the array, which was 21.5% under standard test conditions (STC). The nominal energy of the array was 217810 kWh, whereas the hydraulic energy was 120274 kWh. This difference is due to losses, the most important of which are array losses owing to high temperatures at a rate of 9.83% and converter losses during operation at a rate of 3.21%. The pump's operating electrical energy was 165414 kWh, and its hydraulic energy was 120274 kWh, resulting in a pump efficiency of 72.7 %. The pumped water volume reached 370570 m3/year, while the water requirement was 370475 m3/year, indicating that the system was able to meet the water requirements. The performance ratio was 74.1%, which is deemed satisfactory. This signifies the validity of the design and the dependability of the PV-powered water pumping system.