Performance improvement of a building integrated photovoltaic system

Abstract

In this study, the effect of fins integration on the operating of a Building integrated photovoltaic (BIPV) system is investigated using CFD simulations. Various designs of the cooling system, directly attached to the rear side of the PV cells, are proposed and analyzed. The considered extended heat transfer surfaces are straight and wavy fins of different shift angles and the corresponding effect on this system operating is evaluated. Results revealed that the proposed cooling techniques have proven effective in reducing the solar cell average temperature, thereby increasing the electrical conversion efficiency for the corresponding system. Concerning the best improvement, it corresponds to wavy fins with a shift angle of 180° where a temperature reduction of about 15°C was noted (T* = 1.8), which allowed an increase of the electrical efficiency achieving 8.2%. In this wavy fins equipped system, curved inserts allowing the flow to be directed between each two successive fins, are introduced. The proposed system provides better heat exchange, as shown in the Nusselt number analysis; the corresponding average Nusselt number is increased up to 81% compared to the BIPV without fins and up to 16% compared to the system with only wavy fins. The resulting improvement of heat dissipation affected the PV temperature’s levels and consequently allowed an increase in the BIPV system electrical efficiency of about 11% compared to the system without fins. Similarly, a more uniform temperature distribution is noted, which directly affect the BIPV system life time.