Environmental evaluation of a combined system composed of micro grid and district heating and cooling

Abstract

Co-generation system and district heating and cooling system have been applied to urban areas to realize a low-carbon society. However, CO₂ emissions from operation division including commercial buildings are still on the increase. Hence researches of micro grid have been conducted as one of the countermeasures to realize a low-carbon society. Here, it seems that the district heating and cooling system is operated effectively under the urban site micro grid network. Thus in this report, a combined system composed of micro grid network and district heating and cooling was investigated to minimize CO₂ emissions with a variation of a combination of energy saving systems. The combined system in this study interconnected 3 commercial-scale utility customers with different electric demands and thermal demands. In addition, a conventional energy supply system and district heating and cooling were selected as subjects of comparison with the combined system. Furthermore, 4 kinds of heat-to-power ratio were set by changing the total floor space of each building. In these conditions, annual CO₂ emission from each energy supply system was simulated by using a numerical software GAMS/BARON. The calculated CO₂ emission was compared with one another in each heat-to-power ratio.