This paper proposes a bi-level optimization model to maximize the net revenue of a power distribution company owning energy storage systems. Furthermore, the proposed model also takes into account the uncertainty of load forecast based on a set of multiple scenarios in order to assess its impact on the maximum net revenue of the power distribution company. This bi-level optimization model is transformed into the single-level mixed-integer linear programming model by using the Karush-Kuhn-Tucker optimality conditions and strong duality theorem. This single-level optimization formulation can be effectively solved by using standard commercial solvers such as CPLEX. The proposed model and the effects of the load forecast uncertainty on the net ...