An Engineering Systems Sensitivity Analysis Model for Holistic Energy-Water Nexus Planning

The energy-water nexus is an area of increasing global concern and research. In several existing publications on the subject, the challenges of water use for power plant cooling and energy use for water supply are handled seperately. There is however also a need to consider the totality of interactions between the different elements of the engineered water and electricity systems, thus creating a system-of-systems model. A model of this form integrates water use for electricity supply and electricity use for water supply into a single framework, thus elucidating a wide range of interactions which can be influenced by policy and management decisions to achieve desired objectives. An engineering model capturing these interactions and based on first-pass models of the underlying physics of the various coupling and boundary points has been developed in previous work. In this work, the Jacobian of the resulting system of equations has been determined for a particular illustrative case. This Jacobian enables a sensitivity analysis of the inputs and outputs of this system-of-systems to changes in water and electricity demand to be carried out. As a concrete example, the Jacobian is used to examine the effect of a 10 % growth in both electricity and water demand on the set of system inputs and outputs.