With the deepening of the reform of the power system, electricity sales companies are required to explore new business models and provide multi-faceted marketing programs for users. At the same time, with the reduction of energy storage (ES) costs and the gradual maturity of technology, user side ES, especially Battery ES, has become an effective means for enhancing users` power supply reliability and reducing electricity bills. Battery ES, as the standby power supply, has a vast user side application. The configuration of ES can help users to ameliorate power quality and reduce electricity cost. It is a critical strategy for electricity sales companies to improve their competitiveness as well. Firstly, this paper analyzes the user side ES and introduces the user side ES development status and relevant policies. Then, we establish an ES configuration optimization model based on the cost–benefit system. To determine the optimal ES capacity of the system’s storage capacity, non-dominated sorting genetic algorithm with elite strategy (NSGA-II) is used as the method solving model. Finally, according to the cost-effectiveness of ES and the period of a contract signed by users, a price package with ES configuration is designed for users to choose.