Production and thermal properties of phase changing materials for cooling photovoltaic batteries

Due to the rapid depletion of non-renewable energy sources due to the increasing world population, the demand for the use of renewable energy sources has been increasing in order to meet the increasing energy needs in recent years. Photovoltaic systems are at the forefront of the efficient use of solar energy, which is in the first place of renewable energy sources. Photovoltaic systems are systems that produce electricity from solar energy. The most important disadvantage of photovoltaic systems is the overheating of the panels. Phase change materials (FDM) are materials that have high heat storage properties during melting-freezing in the appropriate temperature range. Due to their high heat storage capacity, they are used for heating and cooling purposes in different areas. In order to prevent the overheating problem in photovoltaic systems, the use of FDM has become widespread in recent years. It has been determined that the studies are mostly focused on macrocapsulation. In the thesis study, taking into account the literature studies, cetyl alcohol, palmitic acid, butyl stearate, which has a melting-freezing range at a temperature suitable for the working range of photovoltaic panels, was first microencapsulated in pure form by emulsion polymerization method. In the second step of the study; Eutectic mixtures of cetyl alcohol, palmitic acid, butyl stearate at different ratios were prepared. The obtained eutectic mixtures with suitable temperature and enthalpy values were also microencapsulated by emulsion polymerization method. The heat storage/dissipation capacities and chemical structures of the obtained microcapsules were determined by DSC and FT-IR spectroscopy, respectively, and Scanning Electron Microscopy (SEM) was used for the morphological examinations of the microcapsules. The thermal behavior and thermal shape stability of microencapsulated FDMs with suitable melting-freezing temperature and latent heat capacity were investigated with the help of a solar simulator. At the end of the study, it was determined that the pure microencapsulated palmitic acid and the palmitic-cetyl alcohol among the eutectic microencapsulated PCMs have suitable thermal behavior and thermal shape stability for their use in photovoltaic panels for cooling purposes.