A Process Systems Approach on the Optimisation of Water and Power Networks using a Discrete-Time Framework

Abstract

Rising water and energy demands due to the increasing global population and economies have necessitated solutions for sustainable management of water and power distribution networks. Drawing from the concept of the water-energy nexus, studies have integrated the operation of water and power distribution networks to increase efficiencies of the other. The inherent flexibility of power intensive operations in the water distribution network can improve power grid stability through demand-side management. Concomitantly, the water distribution network can take advantage of time-varying electricity prices offered by the power distribution network to reduce operating costs, as well as improve their energy efficiency through optimal scheduling. In this work, a discrete time MINLP model is proposed to solve a short-term scheduling problem resulting from the integration of water and power distribution networks. The developed model ensures that detailed modelling of storage facilities in the integrated networks, as well as complete capture of the water-energy nexus between water and power distribution networks are achieved. An illustrative example is used to show the applicability of the model. Results showed a 2.88% increase in cost savings for the detailed modelling of the storage facilities in comparison to a black-box model, whereas the complete capture of the water-energy nexus led to an increase of 0.57% in the overall operational costs.