Thermal stabilization and energy harvesting in a solar PV/T-PCM-TEG hybrid system: A case study on the design of system components

Abstract

In PV cells consisting of p-type and n-type semiconductor materials, electricity is produced with part of the solar radiation coming to the cell surfaces, while the rest causes the cells to rise in temperature, thus decreasing the conversion efficiency. Therefore, controlling the cell temperature is very important in terms of conversion efficiency. In this paper, passive cooling was performed by storing the heat acting on the PV panel with a 40 W harvesting capacity in the phase change material (PCM) in contact with the back surface. Simultaneously, active cooling was achieved by transferring the heat stored in the PCM to the hot-side surface of the integrated thermoelectric generator (TEG) with the help of the heat transfer fluid circulated in the copper pipes inside the PCM. Thus, the base hybrid system (PV/T-PCM-TEG) design (Case_1), which increases thermal stabilization of cells, was realized. While 20 thermoelectric modules are used in TEG, RT55 paraffin wax is used as PCM in the empty space on the back surface of the PV panel. In addition, to improve the PV/T-PCM-TEG system efficiency, three different cases were created by adding Al2O3 nanoparticles into the PCM (Case_2) and by placing copper fins around the copper pipes (Case_3). As a result, the power output of PV/T-PCM-TEG is 10.29%, 12.73%, and 14.22% higher for Case_1, Case_2, and Case_3, respectively, than the standard PV panel. In addition, the maximum PV panel efficiency is 30%, while the efficiency of PV/T-PCM-TEG increased to 32.8% with Case_1, 33.9% with Case_2, and 35.2% with Case_3.