Electric Water Heaters for Transactive Systems: Model Evaluations and Performance Quantification

Electric water heaters (EWHs) are opportune appliances for implementing demand-side control. EWH models serve as a fundamental step toward accurately estimating EWH flexibility potential and designing proper control strategies. Existing studies have adapted numerous modeling approaches in evaluating the potential of EWHs for a variety of grid applications. This article presents an analytical study that evaluates the performance of state-of-art EWH models in terms of accuracy and computational complexity for adaptation in evaluation studies for transactive systems. The work also proposes a novel transactive control strategy that optimally utilizes the thermal inertia of EWHs for providing grid services. The performance of the control strategy and the impact of modeling accuracy are evaluated for device-level and feeder-level use cases using the IEEE 123 node distribution system. The simulation results illustrate the effectiveness of the control strategy in reducing the feeder demand during the peak period by 15% and also quantifying the impact of using simplified modeling approaches for determining the potential of EWHs for providing grid services.