Assessing the demand response capacity of U.S. drinking water treatment plants

Abstract

This study assesses the spatio-temporal electricity consumption and demand response (DR) capacity of U.S. drinking water treatment plants (DWTPs). We account for the installed unit processes at each plant, the electricity intensity of each unit process, the compatibility of a unit process with DR participation, and the approximate volume of water treated at each DWTP during different months of the year. We then perform a parametric analysis to calculate the shiftable load from DWTPs as a function of the length of the load curtailment period (TC), the ratio of the maximum treatment capacity to the peak-day demands of DWTPs (rmax), and the time of the year. The results of the parametric analysis suggest that the total DR capacity of U.S. DWTPs in 2018 varied between 140 MW and 610 MW as a function of TC, rmax and time of the year. We also find that the total electricity use by DWTPs has increased 25% from 2013 to 2018, largely due to the rapidly increasing adoption rate of reverse osmosis processes. These results indicate that DWTPs provide only minimal DR capacity in most locations in the U.S, but that further electrification of the drinking water treatment sector may significantly increase this DR capacity in critical geographic locations during peak summer months.