Design of Roof Morphology for Increased Solar Potential of BIPV/T Systems

摘要

This paper presents a design methodology of housing units' roofs for increased solar potential. The basic principle is that complete near-south facing roof surfaces are used as extended surface solar collectors that generate both heat and electricity. The design of the roof surface morphology incorporates the application of building-integrated photovoltaic/thermal (BIPV/T) system that generates electricity simultaneously with useful heat. The methodology is based on an approximate model aiming at finding the correlation between thermal and electrical output of the BIPV/T system, and on analysis of the effect of combinations of tilt and orientation angles of the BIPV/T system. Optimal configurations are applied to the roof of a rectangular housing unit. Gable roof with 45° tilt angle is used as reference. Results indicate a near-constant correlation between thermal and electrical output of a BIPV/T system, under a fixed air fan speed. Some roof shape designs enable increasing the potential of BIPV/T systems by up to 30%, as compared to the reference roof. In addition to optimizing energy production, the integration of photovoltaic/thermal systems in surfaces with different orientations enables a spread of the timing of peak electricity generation over up to 6 hours, which can reduce the mismatch between demand from the grid and supply to the grid.