Integrated Energy Flexibility Management at Wastewater Treatment Facilities

On-site batteries, low-pressure biogasstorage, and wastewaterstorage could position wastewater resource recovery facilities asa widespread source of industrial energy demand flexibility. Thiswork introduces a digital twin method that simulates the coordinatedoperation of current and future energy flexibility resources. We combineprocess models and statistical learning on 15 min resolution sensordata to construct a facility's energy and water flows. We thenvalue energy flexibility interventions and use an iterative searchalgorithm to optimize energy flexibility upgrades. Results from aCalifornia facility with anaerobic sludge digestion and biogas cogenerationpredict a 17% reduction in electricity bills and an annualized 3%return on investment. A national analysis suggests substantial benefitfrom using existing flexibility resources, such as wet-weather storage,to reduce electricity bills but finds that new energy flexibilityinvestments are much less profitable in electricity markets withouttime-of-use incentives and plants without existing cogeneration facilities.Profitability of a range of energy flexibility interventions may increaseas a larger number of utilities place a premium on energy flexibility,and cogeneration is more widely adopted. Our findings suggest thatpolicies are needed to incentivize the sector's energy flexibilityand provide subsidized lending to finance it. Design optimization tool for assessing the financial benefitsof enhanced electric power demand flexibility at wastewater resourcerecovery facilities