# Enhancing Monocrystalline Solar Module Efficiency through Front-Surface Cooling with 96% Alcohol
## 1 Introduction
They concluded that water, as a working fluid, has the best thermal performance compared to pure ethylene glycol and a mixture of water and ethylene glycol. [PERSON] et al. [27] cooled a silicon solar module with an area of 0.13 m\({}^{2}\) with water and a liquid filter made of an alcohol mixture. The upper glass cover of the module was removed, and in front of the module at a distance of 0.02 m, a coated glass was placed. The glass contained a mixture of ethylene glycol, propylene glycol, and glycerol in the ratio of 1:1:3 (liquid filter). The mixture used had high radiation transmittance in the spectral range specific to silicon (600-900 nm), as well as high absorption of the IR and UV spectral ranges, which increased the operating temperature of the solar module. With this cooling technique, the module's output power was increased by about 2.4 times. High operating temperatures of solar modules reduce their lifetime as well as the lifetime of the entire photovoltaic system. For this reason, it is necessary to efficiently cool the solar module with some suitable cooling technique in order to remove the excess heat [28]. Although it is well known that water is safe and eco-friendly solvent, it is valuable resource and with time not low-cost as it used to be. Alcohol, with the addition of nanoparticles, is utilized for cooling the back side of the module. Even though, this cooling method is more expensive and complicated, its advantage is that there are no losses caused by evaporation. In the case of the module cooling with alcohol from the front side, in closed cooling systems, polluting influence of alcohol is at low level but gain achieved by cooling is unneglectable. Given that alcohol evaporates much faster than water, the idea was to experimentally monitor the change in module temperature and electrical characteristics by cooling it from the front. Also, based on available literature, this type of examination of the effect of alcohol cooling from the front is not often investigated. The aim of this was to experimentally determine the changes in output power of the solar module during the cooling process using 96% ethyl alcohol and to keep the temperature of the cooled module below 47 \({}^{\circ}\)C through a series of short cooling and heating cycles. For this purpose, an active cooling system was constructed. A plastic pipe with numerous holes was placed on the upper edge of the module, in order to form a thin layer of fluid on the front side of the module. At the same time, a pipe was placed on the lower edge of the module to collect and return the fluid back into the tank. The plastic tank was insulated during the experiment to prevent heating of the working fluid. The cooling system was equipped with a submersible pump to facilitate alcohol circulation. Continuous measurement of output power of referent and cooled solar modules were done before, during and after five cooling cycles. The optimal duration of the cooling and heating cycle of solar module was determined. After five cooling cycles, increase in power and efficiency as well as cooling and evaporation rate were achieved.