Enhancing user comfort models for demand response solutions for domestic water heating systems

Demand Side Management (DSM) solutions for domestic Water Heaters (WHs) can assist consumers benefit financially by optimizing their energy usage. However, users' dissatisfaction caused by negative impact of DSM on their comfort may force them to reject the provided solutions. To facilitate DSM adoption in practice, there is a need to account for user comfort and to provide users with control strategies to balance energy consumption and their comfort. Comfort models used for WHs typically account for only variability of the temperature of running water. This paper extends such typical user comfort modeling approaches by considering the tap water flow as a possible variable during water activities. The model to relate tap flow and users' comfort is the first contribution of this paper. The second contribution of this paper is the flow rate control mechanism aligned with the user comfort model by means of the multi-objective optimization. Simulations for different water activities demonstrate that the control mechanism coupled with the suggested user interface can inform the user about multiple trade-offs between electric consumption and user flow discomfort, and thus can inform about possibilities to rationally save energy for water heating. A set of suggestions on how to organize the user interface is the third contribution of the paper.