Optimal centralized integrated energy station site approach based on energy transmission loss analysis

Summary Centralized integrated energy station, which combines electrical power, gas, and heat supplying source together, is emerging with the development of an integrated energy system. In the previous works, the site optimization approaches of energy stations were developed for electrical power and gas sources. In these approaches, the candidate sites only include user nodes. However, with the development of the integrated energy system, the previous approach cannot be applied effectively for the system containing heating networks with high energy transmission loss. The energy transmission loss must be calculated accurately in the optimization approach rather than valued by the simple linear model. This paper aims to propose an optimal site approach of a centralized integrated energy station, in which all possible candidates of energy station sites are considered. The candidates can be any point in the whole energy supplying area. The analysis of energy transmission losses, based on nodal energy flow models, in pipelines and feeders, are incorporated. The simultaneous optimization of the station site and energy distribution networks is conducted. It is found that the energy transmission loss is significant in heating networks; therefore, network optimization should be carried out considering exact energy transmission loss. The optimal station site obtained in the present work has reduced 2.3% of the life cycle cost much more than that obtained from the previous method selecting a site from the user node. A noticeable reduction in life cycle cost, 2.6%, can also be achieved when using the proposed approach for a single energy source station. Moreover, for integrated energy systems, it is found that the adoption of the centralized integrated energy stations is more competitive comparing with the adoption of the single energy source station. A centralized integrated energy station plays a vital role in the integrated energy system, which has been promoted globally. The site selection of centralized integrated energy stations is essential but complex and should be carried out combined with network optimization. However, the traditional site selection method for electrical substation cannot be applied for the considerable energy transmission loss in district heating networks. This paper aims to propose an optimal site approach of a centralized integrated energy station, in which all possible candidates of energy station sites are considered. The exact energy t