Reduction Potential of CO₂ Emission by Integrated Energy Service System in Urban Area Considering the Generation Mix of Electric Utility

Abstract

Optimization of urban energy systems in a small urban area can reduce CO₂ emission from the specific area. However, large-scale introduction of these locally optimized energy systems in a wider region may not necessarily reduce CO₂ emission from the whole region. This is because optimization in a small area depends on CO₂ emission per unit of commercial electricity that is determined by an assumed generation mix of commercial power. If these locally optimized energy systems are introduced on large scale, the optimal generation mix would be modified. This paper investigates the relation between the scale of locally optimized energy systems in a region and the CO₂ emission from the region. The analysis is performed by developing an integrated model that consists of two separate optimization models, i.e., one is for energy systems in a small area and the other is for determining an optimal generation mix. The developed model is applied to Kansai region of Japan. The results show that large-scale introduction of locally optimized energy systems can generally reduce CO₂ emission from the whole region.