# Enhancing Monocrystalline Solar Module Efficiency through Front-Surface Cooling with 96% Alcohol
## 3 Results and Discussion
### Power and Efficiency of Cooled and Uncooled Solar Module  
Changes in the power output of a solar module immediately before, during, and after five cycles of active cooling are presented in Figure 10. The upper curve represents the change in power of the cooled solar module, with the indicated moments at which each cycle starts and ends, where the labels I, II, III, IV, and V refer to the sequence number of the cycle, and the labels s and f refer to the beginning and end of the cycle, respectively. The Figure 10 shows that the power of both modules increases with an increase in solar irradiation intensity. After solar noon, a slight decrease in solar irradiation intensity leads to a small decrease in the power of the modules. Before the start of the first cooling cycle, the powers of the solar modules differ slightly. However, an increase in power of the cooled solar module with each cooling cycle is clearly observed, as well as the decrease in power corresponding to the heating process of the module. All cycles are characterized by approximately the same form of change in power. During the first 45 s of cooling with alcohol, a rapid increase in power is observed, after which the power increases slowly. This time interval corresponds to the rapid alcohol evaporation, due to greater temperature difference between solar module and alcohol. For cycle I, power increased by 3.2% during the first 45 s of cooling, while for cycle II, III, IV, and V, the power increased by 2.7%, 2.7%, 2.6%, and 2.7%, respectively. The moment  
Figure 10: Change in solar modules power immediately before, during and after cooling, for five cycles of active cooling. immediately after the pump was turned off and the supply of alcohol to the front surface of the module has stopped can be seen, whereby the further increase in power that lasts about 70 s was recorded. It is during this time interval that intense evaporation of the alcohol remaining on the front side occurs. At the end of the first cycle, an additional increase in power from 57.33 W to 57.98 W was recorded, which is an increase of 1.1%. This increase is consistent with the decrease in modules temperature noted for cycle I. At the end of cycles II, III, IV, and V, an additional increase in power by 0.9%, 0.3%, 0.4%, and 0.6% was recorded, respectively. The measured power values before and after the cooling cycles, as well as the percentage difference in power before the start and at the end of each cycle are shown in Table 4.  
Based on the values given in Table 4, it can be seen that the biggest change in power occurred at the end of cycle III, when the power of the cooled module was 4.9% higher than the power of the uncooled module. Before the beginning of the cooling cycle I, when both modules were heated, the power of the cooled module was 0.3% higher than the power of the uncooled module. Before the beginning of cycle V, the power of the cooled module was higher by 1.1% due to the greater difference in modules temperature. The pump used in the experiment operated in five minutes cycles and consumes power of 2.32 W/m\({}^{2}\) per hour, which applies for one sunny day in November. Figure 11 shows the change in solar modules efficiency before, during, and after cooling for five cycles of active cooling.