Abstract: The sharing of energy storage within a distribution station area presents an important approach to promoting the local consumption of distributed photovoltaic, enhancing the reliability of power supply in the distribution station area, and improving the operational benefits of energy storage. To maximize the economic benefits of distributed photovoltaic users within the distribution station area, the optimal capacity configuration and operation strategy of shared energy storage are formulated as a cooperative game based on two-stage stochastic optimization, and the egalitarian Shapley value is used to equitably allocate the cooperation cost of the grand coalition. First, the coalition value of the shared energy storage cooperative game is characterized as the total coalition cost that includes the energy storage investment cost and the user electricity cost. Subsequently, it is proved that the proposed cooperative game model satisfies superadditivity, indicating that all photovoltaic users in the distribution station area are motivated to form a grand coalition to cooperate in investing in and operating energy storage devices. Finally, a cost allocation scheme based on the egalitarian Shapley value is proposed, which achieves a rational allocation of the total cost of the grand coalition by considering the principles of egalitarianism and utilitarianism. Numerical analysis indicates that the cooperative game-based energy storage sharing in the distribution station area can save photovoltaic users’ costs, improve the self-balancing capacity of the area, and increase the local consumption rate of distributed photovoltaic power.