Contrasting the effects of real-time feedback on resource consumption between single- and multi-person households

Residential energy consumption accounts for 25% of Europe's greenhouse gas emissions. Consumption feedback delivered via technology has been reported to produce from none to 20 percent energy savings. Yet it is still unclear how to best leverage the full potential of smart sensors and feedback information to achieve a high and persistent impact on user behavior and awareness. Showering is an ideal domain to investigate the effectiveness of different household constellations and different types of feedback information on resource: the effects of user actions are immediately visible, can easily be controlled by the user and are quantified easily. For that purpose, we developed a shower meter and display that measures and stores event-based time series data and provides users with in-situ real-time information about the current shower event. In a 2x3 randomized controlled trial with 697 Swiss households over two months, the impact of different feedback versions and household size on the dependent variables energy and water usage is analyzed. Measurement data are supplemented and evaluated with self-reported survey data before and after the field study. First results after the collection of the devices indicate a very promising savings potential for such feedback technology and important contributions to the broader literature on behavior change and social norms in general.