Multi-Criteria Optimization of a Heat Pump Based District Heating System in the City of Beijing

A more widespread usage of heat pumps would contribute to significantly reduce both local and global environmental impacts. This is particularly relevant within cities, where advanced integrated energy systems incorporating heat pumps and associated with district heating networks offer interesting opportunities for CO2 emissions abatement. Planning for medium or long term investments in an unsettled economic and regulatory environment in particular with regards to global environmental issues and accounting for the technical evolution requires the ability to deal with a large number of parameters. This paper illustrates through the case study of a district heating in the city of Beijing the ongoing efforts towards multi- criteria optimization of advanced energy systems in order to provide decision makers with a coherent technology assessment methodology. A superstructure including both centralized and decentralized heat pumps and cogeneration units associated with a district heating network is considered for the heat supply of two urban areas, respectively residential and commercial buildings. A simultaneous consideration of thermodynamic, economic and environmental criteria is used to identify the most interesting alternatives in the chinese context. The results of the optimization process, obtained in the form of Pareto frontiers, reveal their economic and environmental performances, as well as deliver valuable information on their absolute and marginal cost of CO2 emissions reduction. This information allows to define the tax level or the emissions permit price required to induce enough economic incentive for their implementation.