Shape Study on a Green Roof Integrated Photovoltaic System for Bi-objective Optimization of Investment Value and CO2 Emission

Abstract

A simulation methodology has been proposed for evaluating the performance of CO2 Emission (CE) and Investment Value (IV) of the shape of the Green Roof Integrated Photovoltaic System (GRIPVS) of a Wooden Detached House (WDH) using Genetic Algorithm (GA). CE and IV, acting as evaluation indices were studied in this paper. It is an analytical comparative study of searching for an efficient GRIPVS by maximizing IV and minimizing CE simultaneously. Considering the influence of the climate condition on the amount of electric power generation of PVS, three typical locations in Japan are taken into account: Sapporo, Tokyo and Naha. The GRIPVS was treated as a bi-objective problem of combinational optimization. Through numerical GRIPVS’ representation evaluated by GA, the optimal Pareto curve of each location is found. Feasible solutions illustrated that: GRIPVSs with a larger southern roof area and fully covered with PVS perform the best concerning IV than others, and the pitches of GRIPVSs in the given locations should be less than their local optimal solar absorption pitches. To minimize CE, GRIPVSs with larger roof pitches for enlarging the PVS installation area to generate more electric power and larger greening area to absorb more CO2 are needed. © 2007, Architectural Institute of Japan. All rights reserved.