Joint Generation and Water Desalination Expansion Planning

Infrastructure expansion planning is the process of deciding what, where, and when to build to meet the future needs. In some arid regions, with severe freshwater scarcity, water is produced via desalination. Since desalination is an energy intensive process, this leads to a high level of interdependence between the water and energy systems. Traditionally, the two systems are planned for separately and sometimes even operated with little to no coordination. The lack of coordination leads to inefficiencies that can be eliminated with better models. This paper contributes in developing a joint generation-water expansion planning model that incorporates the interdependence between the two systems, and thus finds a superior plan. To develop the model, power and water operational constraints are implemented linking both system in planning and operations levels. The paper quantifies energy consumption needs of both thermal and membrane desalination processes. Furthermore, the paper establishes a water consumption duration curve to model the correlation between water and power demand. Simulation studies are presented on a modified IEEE RTS system. This proposed joint planning and operations model was compared to a separate generation-water planning and operations modeling method to show the out performance the joint model offers.