Two-phase collaborative optimization and operation strategy for a new distributed energy system that combines multi-energy storage for a nearly zero energy community

Abstract

The combination of a distributed energy system and multi-energy storage system has the potential to use renewable energy on a large scale and to further improve the system’s energy efficiency. Therefore, a new type of distributed energy system that combines multi-energy storage is proposed in this paper. Its novelty is that the three types of energy storage, i.e., cold, heat and electricity, are considered simultaneously, and the electric vehicle load is also included in the distributed energy system in combination with the multi-energy storage system, which allows full consideration of the effect of multi-energy storage on the distributed energy system. Three operation modes are proposed to give full play to the advantages of the new system according to the charging mode for electric vehicles. Subsequently, a two-phase collaborative optimization method for system configuration and operation optimization is proposed, and it is applied to a nearly zero energy community. The results show that the primary energy savings rate of the distributed energy system that combines multi-energy storage is 53.5% when the electric vehicle charging load is provided by the new system, which is 17.5% higher than that of the traditional distributed energy system, while the annual cost savings rate increased by only 8.3%. In addition, the hourly operating cost of the distributed energy system that combines multi-energy storage is also significantly reduced compared with the separated production system. Therefore, the method of two-phase collaborative optimization in the new system proposed in this paper can be used to realize the optimal system configuration and operation design for energy savings and consumption reduction. Finally, the new system can provide a feasible scheme for the energy supply of a nearly zero energy community in the future.