Operation of interconnected power and freshwater networks

As freshwater demand continues to rise and conventional freshwater resources decline, the interaction between the freshwater and power sectors is becoming increasingly relevant. Coordinating both systems entail minimizing the operation costs of the power and freshwater system while supplying the demands of electricity and freshwater and complying with operational constraints. This is particularly relevant in Middle Eastern regions, which have limited availability of freshwater resources. Careful coordination of electricity generation and freshwater production is beneficial for both the power and the freshwater systems. For example, producing excess freshwater at hours of low electricity production cost and storing it for usage at hours of high electricity production cost is economically advantageous. We use detailed models for the operation of the power and freshwater systems. That is, the power system operation is represented through a network-constrained unit commitment model, while the freshwater system model includes nonlinear representations of the freshwater production and transportation. The resulting problem is computationally intractable for large-scale systems. To achieve tractability, nonlinearities in the freshwater model are linearized. The final model is a tractable mixed integer linear optimization problem that is solved using a state-of-the-art branch-and-cut solver. Simulation results demonstrate that a coordinated scheduling results in lower cost and lower peak as compared with uncoordinated scheduling.