Optimum Design for Residential Photovoltaic-Thermal Binary Utilization System by Minimizing Auxiliary Exergy

Abstract

Side-by-side system, PVT hybrid system, and side-by-side PVT hybrid system can be designed for a self-sufficing system as a residential binary solar energy utilization. We designed and did annual simulation of the performance of three systems-PV with flat plate collector (PV/FPC), photovoltaic-thermal hybrid (PVT), and PV with photovoltaic-thermal hybrid (PV/PVT)-with auxiliary electrical heat pump. In this paper, Solar Energy Fraction (SEF) or Auxiliary Exergy Fraction (AUX) is adopted as a figure of merit of the system evaluation. We clarified the characteristics that these indexes are affected by AUX's COP and by the ratio of DHW (domestic hot water) load: annual synthetic load.
As a result, the best figure has achieved by the side-by-side PV/PVT hybrid system. Using PVT with PV leads to the improvement of the PVT alone system's SEF or AEF. It is found that glazing is indispensable for PV/PVT system with AUX's COP of 1, and is unnecessary for PV/PVT system with higher COP.