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Abstract: The importance of developing a method to bridge the gap between the current increasing trend of CO2 emission from the commercial sector and the reduced emission level for ensuring long-term sustainability has increased. Various concepts exist for managing the energy use and CO2 emission. These concepts can be categorized into advancement in technologies, dissemination of energy saving measures in buildings, optimization of local energy generation and distribution systems, spatial building stock pattern management, and improvement in CO2 emission factor of the grid electricity. In this paper, we propose a modeling approach for energy use in the commercial sector in order to evaluate the options involved in the abovementioned energy management concepts in an integrated manner. In this modeling approach, a district is dealt with as a basic unit. Districts are first classified into several categories according to the spatial building stock pattern, or urban form. The end-use energy consumption per unit floor area is then calculated for each district category using a simulation of energy use in buildings in a representative district; this is used for quantifying the total end-use energy consumption at the municipal level. We carried out a case study in order to demonstrate the simulation capabilities and features of the suggested modeling approach in contrast with the conventional modeling approaches. In this case study, certain scenarios of CO2 abatement integrating the energy management concepts are applied in the commercial sector of Osaka city, Japan, in order to investigate alternative avenues toward which policy efforts must be directed. [Copyright &y& Elsevier]

Abstract: This paper investigates alternative prospects for an urban energy system from a long-term perspective in order to achieve a reduction in CO2 emission by more than 50% of the current emission in the Japanese commercial sector. This will assist in making strategic choices with regard to the implementation of available technologies in order to create a substantial change. A simulation model based on the bottom-up approach – a fundamental part of the evaluation framework of technology implementation scenarios – provides insights into the changes required in all the components of urban energy systems from the equipment level to the entire building and systems level and finally to the neighborhood and city levels. This model is applied to the Yodoyabashi district, a central business district in Osaka, Japan, in order to predict the end-use energy consumption and CO2 emission under various scenarios. This is based on different concepts of community energy management. The results of this case study suggest that we can achieve a reduction of 60–90% of the current CO2 emission by the middle of the 21st century. [Copyright &y& Elsevier]