Abstract
Material flow analysis (MFA) is a method for analyzing the relationship between economies and environmental issues. MFA
is usually on the basis of weight unit. However, materials have a strong relationship with energy. Therefore, we intend to
improve MFA by introducing the viewpoint of energy. In this study we define a concept of virtual energy of each material.
Using the concept of the virtual energy, we evaluate the virtual energy intensity of fuels, major materials (such as steel,
aluminum, copper, plastics, rubber, and glass), and automobiles that represent complicated goods. We calculate the virtual
energy intensity of not only new goods but also wastes and used goods such as steel scrap and used cars. We also evaluated
the virtual energy flow of the major goods including the wastes and the used goods between Japan and abroad. We consider
the concept of the virtual energy is a powerful tool for energy flow analysis including wastes and used goods.
