Maximum Demand Comparison of Aggregated Load Profiles for Vertical and Horizontal EWHs Due to a Fixed Draw Event

This paper shows a comparison of the vertical and horizontal tank orientation and the associated maximum demands from synthesized aggregated load models for various grid scenarios. Aggregated load profiles are produced by replicating a 50 litre (50% capacity) draw event for a 100-litre dual-mountable electric water heater (EWH) for each orientation. A total of 416 load profiles are produced containing 208 sets of horizontal and vertical aggregated profiles for comparison. Two factors are varied, (1) total EWH population from 1 to 1 million in various increments and (2) peak time window for initiating EWH draws ranging from 1 to 12 hours, where a Gaussian distribution is applied to the times each EWH starts participating on the grid. The resulting aggregated load profiles show that EWHs in the vertical orientation produce a higher aggregated maximum demand whereas the horizontal orientation can have a much lower aggregated maximum demand to a ratio of 0.58. A maximum demand ratio P h /P v of 0.80 is determined for a scenario similar to normal grid operation for a peak time window of 4 hours. The significance of this work is to quantify the difference in maximum power demand of a population of EWHs due to tank orientations in a controlled simulated environment.