Advancing Demand Response in the Water Sector

A novel energy demand management software (DMS) called WaterWatch, designed and built by the University of California, Davis Center for Water-Energy Efficiency, offers safe recommendations for water distribution systems to adjust their energy loads in response to various signals. The software leverages hydraulic modeling, machine learning, and optimization research to produce near real-time operational recommendations. WaterWatch was piloted at the Moulton Niguel Water District in Southern California for 12 months, and it tracked water and energy consumption, along with greenhouse gas emissions. Additionally, a simulation model was created to assess the potential for energy load shifting across California’s public water systems and its impact on the statewide energy grid. The statewide model identified that water distribution pumping accounts for at least 1.2 percent of California’s total energy consumption. The model clearly demonstrated a high degree of capacity to shift, ramp, and modulate energy demand statewide throughout the day to meet nearly any energy sector objective, given a properly designed energy tariff or price signal. Under the idealized energy tariff without demand charges, the study found that the water distribution sector could annually shift energy demands by up to 1.07 terawatt-hour or reduce renewable electricity curtailment by 68 percent. The WaterWatch demand management software consistently reduced energy demand by 4.03 percent over five days with each use during the pilot. With continued weekly use, the pilot site would be expected to save up to 311.58 megawatt-hours of energy consumption annually, or 48.36 metric tons of carbon dioxide equivalent (MTCO2e) of indirect greenhouse gas emissions. Scaled to all public water systems in California, it is anticipated that use of WaterWatch would result in the savings of up to 131.8 gigawatt-hours annually or 20,457 MTCO2e of indirect emissions.