*2.3. Optimization Procedure*

As the hybrid system operating variables have a nonlinear relation, it is required to find a nonlinear solving algorithm to catch the optimal design. Therefore, the Generalized Reduced Gradient (GRG) algorithm was used. This algorithm can figure out the capacities of the hybrid systems. The adoption of the optimization procedure is depicted in Figure 2. Moreover, the optimization objective, constraints, and decision variables are given in Table 1.

**Figure 2.** The optimization procedure of the hybrid system components.

**Table 1.** The components of the optimization problem.

