Techno‐economic feasibility study of an electric‐thermal coupling integrated energy system for commercial buildings in different latitudes

Integrated energy systems (IESs) can make full use of renewable energy and have become a development trend of future energy due to their high energy efficiency. This study aims to investigate the economic, efficiency and environmental performance of electric‐thermal coupling IESs operating at different latitudes. First, multi‐energy integrated systems for commercial buildings are modelled, which presumably operate in Xi'an, Guangzhou and Harbin. The optimal component sizes of these systems are calculated separately using the region contraction algorithm with the objective of the lowest energy cost. In this work, simulation is implemented through the commercial software tool MATLAB. On this basis, a comprehensive evaluation method is presented to evaluate the performance of IESs in the aspects of economic, environmental and efficiency performance. In addition to a comparison with common systems, IESs in different regions are also analyzed, providing a reference for the planning and evaluation of IESs. The results show that the solar radiation and required loads at various geographical latitudes are different, which leads to the diversity of optimal capacity in different cities. In low latitudes such as Guangzhou, the system component sizes are relatively small, in contrast to the results at high latitudes. The system can obtain a low cost of electricity and high cost of heat in low latitudes, but a high cost of electricity and low cost of heat are usually calculated in high latitudes. Moreover, the system has excellent environmental and efficiency performance but poor economic performance in high latitudes, while the system exhibits the opposite results in low latitudes. The above analysis results reflect that the contrast among environmental, efficiency and economic performance needs to be further considered in component sizing optimization and construction of IESs.