HeatDial: Beyond user scheduling in eco-interaction

There has been an interesting development within sustainable HCI, from passive feedback-displays towards more interactive systems that allow users to schedule their energy usage for optimal times based on eco-feedback and eco-forecasting. In this paper, we extend previous work on user scheduling of energy usage in eco-interaction with a study of heat pump control in domestic households. Aiming at using electricity when it is either cheap or green, our approach is to provide users with an interface where they can set temperature boundaries for the home, and interactively evaluate the impact of different settings on predicted energy cost. Based on this input, the scheduling of energy use is done by an automated system monitoring temperatures and electricity prices. We conducted a qualitative study of the HeatDial prototype with 5 families over 6 months. Key findings were that HeatDial supported users identifying and acting on opportunities for reducing costs, but that automation also had an impact on user engagement and highlighted a need for more feedback on how the system intended to act.