Multiple-steps scenario optimisation for pumping plants activation in water supply systems

Economic aspects concerning the high costs related to energy requirements for managing complex water supply systems need a robust strategy, particularly considering the activation of pumping plants. Considering hydrological uncertainties, the definition of strategic rules can ensure energy savings and the well-timed activation of costly water transfers for shortage risk alleviation. The modelling approach has been developed aiming at defining strategic rules of pumps activation thresholds. It considers the need for seasonal variations of activation and the different costs of energy in diverse time slots, according to the usual cost rules adopted by the authorities. Starting with the traditional scenario analysis approach, a new algorithm has been developed considering a multiple-steps scenario optimisation implemented using GAMS interfaced with CPLEX solvers. The results should allow the water authority to establish a robust strategy for pumping activation to guarantee the fulfilment of water demands and to ensure an energy-saving policy.