# Enhancing Monocrystalline Solar Module Efficiency through Front-Surface Cooling with 96% Alcohol
## 1 Introduction  
Global warming is considered to be one of the most hazardous anthropogenic phenomena for the entire planet. Solar modules represent a viable solution to the global energy shortage, offering a clean and readily available form of energy. Solar energy can be considered as a clean and renewable form of energy that is available all over the world. Electricity can be produced by smaller photovoltaic systems in urban areas as well as in large photovoltaic power plants [1; 2]. Research indicates that only 15-20% of the Sun's energy can be converted into electricity, with the remainder being converted into heat [3; 4; 5; 6; 7; 8; 9]. This leads to an increase in temperature and potential overheating of solar modules, which can reach temperatures as high as 70 \({}^{\circ}\)C. The temperature rise adversely affects solar cell efficiency. The mechanism behind this effect is primarily due to the increased rate of electron-hole recombination as the temperature rises. In a solar cell, when photons from the sun strike the semiconductor material, they excite electrons, creating electron-hole pairs. These free electrons and holes then move towards the p-n junction, where they are separated by the built-in electric field and generate a current. However, at high temperatures, the rate of electron-hole recombination increases, reducing the number of free electrons and holes available for generating a current. This results in a decrease in the solar cell's efficiency [10; 11]. The current-voltage curve (I-V characteristic) and the power-voltage curve (P-V characteristic) of a 100 W solar module were investigated depending on the solar irradiation intensity and temperature [12; 13]. As the temperature increases a gradual drop in voltage occurs, while the current does not change significantly. As for the P-V characteristic the increase in the solar module temperature leads to the voltage and power decrease, thereforethe electrical conversion efficiency decreases. The temperature rise of 10 \({}^{\circ}\)C decreases the nominal power by 5 \(W\), i.e., by 5%, and nominal power at 65 \({}^{\circ}\)C was 79.5 W, while the solar irradiation remained 1000 W/m\({}^{2}\). Also, the maximum power point (MPP) descended to the left [12]. Having this in mind, cooling techniques are necessary, and the selection of an appropriate cooling fluid is crucial [3]. The cooling fluid must meet specific requirements such as including high thermal conductivity and to effectively remove heat from the solar module [14, 15]. Common cooling fluids include air, water, nanofluids, and alcohol mixtures. [PERSON] et al. [16] experimentally investigated the performance of a polycrystalline solar module with water cooling. Cooling was performed using a tube (60 cm in length and 2.5 cm in diameter) consisting of 32 holes with a diameter of 5 mm, placed on the upper edge of the module. The cooling system included a submersible pump that pumped water from the tank at a flow rate of 5 L/min. During the experiment, the water temperature in the tank was close to the ambient temperature. By cooling the front side of the module with water, the temperature was reduced from 58 \({}^{\circ}\)C to 32 \({}^{\circ}\)C, and the output power was increased by 10%. [PERSON] et al. [17] studied the performance of actively water-cooled solar modules. They used two solar modules with a single power of 55 W and cooling was done by 24 nozzles. On the front side of the module, an average water flow of 4.4 L/min per m\({}^{2}\) was achieved. The average thickness of the water flow was about 1 mm, and a pump was used to circulate the water. By applying this water cooling technique, the temperature of the solar module was significantly reduced from 60 \({}^{\circ}\)C to 38 \({}^{\circ}\)C. The electrical conversion efficiency was increased by 10.5% compared to the efficiency of the uncooled module. [PERSON] et al. [18] performed an experiment to improve the performance of a solar module by spraying water over the front surface of the module.