Optimization of the energy management in water supply systems

Water supply systems frequently present high-energy consumption, which correspond to the major expenses of these systems. Energy costs are a function of real consumption and the daily energy tariff.

This paper presents a model of optimization to guarantee the delivery of enough water to populations, for each day. Although, in order to achieve that, energy for pumping is needed, representing the main cost for the companies that operate the systems. The model, developed in MATLAB^®, provides the best solution to take in each time step. Simultaneously the population water consumption must be guaranteed, and the hydraulic system restrictions fulfilled. The definition of optimal pumping schedules allows the reduction of operation and maintenance costs associated with pumping energy, as well as the increase of global hydraulic system efficiency. The rules are subsequently introduced into a hydraulic simulator (EPANET), to verify the system behaviour along the simulation period. In addiction, a water turbine is introduced in one of the system's branches. The economical benefits from the generated energy from the water turbine can not be neglected and the wind complementary turbine for pumping supply provides also significant economical savings.