Urban energy structure optimization at the sector scale: considering environmental impact based on life cycle assessment

Abstract

Rising pressure of population growth and economic development, limited energy supplies, and improved concerns over environmental effects have forced decision makers to contemplate comprehensive optimization of urban energy systems planning. A multi-objective optimization model at urban sector scale is proposed in this study to achieve sustainable development of energy, economic, and environmental systems, by integrating objectives of minimal energy consumption, energy cost, and environmental impact. To comprehensively measure the environmental objective, the life cycle assessment method is used to calculate the environmental impact caused by various pollutants in the chain of energy production, transportation, and consumption. Based on the 1995–2010 data, the optimization model is applied to Beijing, China to obtain a reasonable solution of energy mix in 2015 and 2020, where the four energy resources (i.e., coal, oil, natural gas, and electricity which account for over 96% of the total energy consumption) are distributed to the six key sectors (agriculture, industry, construction, transportation, commerce, and household). The results estimate a decline in the proportion of coal to the total energy consumption and an increase for others. The decrease in energy consumption is only observed in the industry sector. It also found that the effect of energy savings and emissions reduction when considering the environmental impact is better than that neglecting the environmental impact. It concludes that the multi-objective optimization model integrating environmental impact is useful for reasonable allocation of energy resources across the urban sectors, which could help balance economic, energy and environmental goals and provide more detailed and practical support for urban energy system management.