Transient simulation of a hybrid photovoltaic-thermoelectric system using a phase change material

In the present study, phase change material (PCM) was introduced as a heat sink attached to a PV-TEG (photovoltaic-thermoelectric generator) to build a PV-TEG-PCM hybrid system. PCM is often used to save a great deal of latent heat during a phase change process with enhanced energy storage capacity. Such a combination controls the system temperature, reduces PV temperature, increases temperature difference across TEG, and improves efficiency. For analysis, a transient, two-dimensional modeling was conducted for two Klein days (the average day for each month) in summer and winter for the city of Shiraz, Iran. Solar radiation, average wind speed, ambient air temperature, as well as heat losses through convection and radiation are included in the model. The validity of the results was tested and approved against experimental studies. Computation was performed for a duration of 24 h. The results indicated that electrical performance of a PV-TEG-PCM is better than that of a PV-TEG and a sole PV systems. Also, the effect of the PCM thickness and melting point temperature was studied to find the optimum material and thickness, which depend on environmental conditions. The numerical two-dimensional unsteady state modeling was implemented by developing a computational code in FORTRAN 90.