ESTIMATION OF ENERGY INTENSITY AND STRUCTURE OF ENERGY-CONSUMPTION BASED ON INPUT-OUTPUT TABLE

The environmental problems are becoming more critical issues these days. The global warming problem caused by carbon dioxide is serious, because energy supPlY for modem industry depends on the usage of fossil fuel. Renewable energy usage is expected to be one of the key technology to reduce the emission of carbon dioxide. Energy systems, however, to gather the renewable energies are tend to be large due to the low energy density, and require large amount of initial input energy. The assessment of the amount of energy to produce equipment and to construct renewable energy system is essential to evaluate the efficiency of systems as energy producer. In this paper, energy intensity is evaluated using Input-Output table and several topics on the use of the table are discussed. The estimation of energy intensity gave reasonable values for Japanese Input-Output table of 1985. In the analysis of energy intensity using Input-Output table, the evaluation of electricity has several alternatives. A method is proposed to modify the structural matrix to manipulate electricity in a unified way. The effect of fixed capital depreciation is considered, which is not counted in normal way of Input-Output analysis. The result shows that the change in considering fixed capital is not so large for energy consumption structure in Japan. Two graphic methods to analyze the structure of Input-Output table are also considered. The inverse matrix coefficient that is the total sum of production to supply unit final demand, is plotted in a special graph to analyze the structure of energy flow from petroleum to automobiles and other products. The effect of transportation sector on the energy flow is analyzed by calculating and plotting inverse matrix coefficient from modified structural matrix. This paper suggests that Input-Output table is useful for energy analysis.