Effects of Short-Term Water Constraints on Electricity Dispatch: A Case Study of ERCOT and SPP Regions

Water is a crucial resource for thermoelectric power plants, and severe drought conditions have the potential to affect power generation and the dispatch of electricity. The Linear Optimization and Assessment of Dispatch (LOAD) model was used to evaluate the effects of short-term water constraints on power generation in two electricity market regions-the Electricity Reliability Council of Texas (ERCOT) and the Southwest Power Pool (SPP)-during the 2018 summer season. Imposition of water constraints in the drought-prone ERCOT region in southern Texas and western regions of SPP led to fuel switching, electricity price increments, increased coal plant cycling, and localized shifting of generation in the regions. Under low-to-moderately high water constraints, the total water consumption decreased in SPP (9.7%) and ERCOT (4.4%) as generation shifted from the water-constrained region to other regions. However, under high water constraints (65% in ERCOT and 85% in SPP), total water consumption rebounded as generation shifted to less water-efficient plants outside of the water-constrained regions. Similarly, emission savings (5.3% in SPP and 1.1% in ERCOT) were a cobenefit of enforced water savings as total emissions also decreased under small-to-moderate constraint scenarios.