Importance of Temporal Resolution, Granularity, and Two-way Feedbacks in the Water-Energy Nexus Modeling

During the last decade, numerical models have been developed to simulate water-energy interactions to support the synergistic management of these resources in face of population growth and climate change. While coupled water-energy models have great potential, the effects of temporal and granular resolutions in the representation of water and energy systems, as well as the differences in coupling approaches have not been thoroughly investigated. Here, we address this research need by applying the WEAP-LEAP coupled modeling system to the Phoenix metropolitan region, which is home for ~4.5 million people and heavily relies on energy-intensive water sources. We conduct experiments where WEAP-LEAP is run (i) at annual and monthly resolutions; (ii) with a different number of demand and supply nodes simulating power plants; and (iii) coupled and uncoupled. Results show that: (i) monthly simulations are able to capture the observed seasonal peaks of energy generation, unlike the annual simulations; (ii) a refined granularity improves estimates of water allocations from specific sources to distinct power plants and, in turn, electricity needed to move and treat water; and (iii) two-way coupled simulations are able to fit better observed estimates of water allocations to different demand sectors and energy generation by all power plants.