Scenario Optimization of Complex Water Supply Systems for Energy Saving and Drought-Risk Management

The management of complex water supply systems needs a close attention to economic aspects concerning high costs related to energy requirements in water transfers. Specifically, the optimization of activation schedules of water pumping plants is an important issue, especially managing emergency and costly water transfers under drought-risk. In such optimization context under uncertainty conditions, it is crucial to assure simultaneously energy savings and water shortage risk alleviating measures. The model formulation needs to highlight these requirements duality to guarantee an adequate water demand fulfillment respecting an energy saving policy. The proposed modeling approach has been developed using a two stages scenario optimization in order to consider a cost-risk balance, and to achieve simultaneously energy and operative costs minimization assuring an adequate water demand fulfillment for users. The optimization algorithm has been implemented using GAMS interfaced with CPLEX solvers. An application of the proposed optimization approach has been tested considering a water supply system located in a drought-prone area in North-West Sardinia (Italy). By applying this optimization procedure, a robust strategy in pumping activation was obtained for this real case water supply system.