One of the great societal challenges that we face today concerns the move to more sustainable patterns of energy consumption, reflecting the need to balance both individual consumer choice and societal demands. In order for this ‘energy turnaround’ to take place, however, reducing residential energy consumption must go beyond using energy-efficient devices: More sustainable behaviour and lifestyles are essential parts of future ‘energy aware’ living. Addressing this issue from an HCI perspective, this paper presents the results of a 3-year research project dealing with the co-design and appropriation of a Home Energy Management System (HEMS) that has been rolled out in a living lab setting with seven households for a period of 18 months. Our HEMS is inspired by feedback systems in Sustainable Interaction Design and allows the monitoring of energy consumption in real-time. In contrast to existing research mainly focusing on how technology can persuade people to consume less energy (‘what technology does to people’), our study focuses on the appropriation of energy feedback systems (‘what people do with technology’) and how newly developed practices can become a resource for future technology design. Therefore, we deliberately followed an open research design. In keeping with this approach, our study uncovers various responses, practices and obstacles of HEMS use. We show that HEMS use is characterized by a number of different features. Recognizing the distinctive patterns of technology use in the different households and the evolutionary character of that use within the households, we conclude with a discussion of these patterns in relation to existing research and their meaning for the design of future HEMSs.

This paper presents results of a three-year research project focused on the emplacement of Home Energy Management Systems (HEMS) in a living lab setting with seven households. The HEMS used in this study allowed householders to monitor energy consumption both in real-time and in retrospective on the TV and on mobile devices. Contrasting with existing research focused on how technology persuades people to consume less energy, our study uses a grounded approach to analyze HEMS emplacement. As an important result, we present here the issue of 'energy literacy'. Our study reveals that, by using HEMS, participants became increasingly literate in understanding domestic electricity consumption. We discuss the role HEMS played in that process and how the acquired literacy changed energy consumption patterns. We conclude that literacy in energy consumption has value on its own and explain how eco feedback system designs can benefit from this understanding.

Reacting to the discussion on global warming, the HCI community has started to explore the design of tools to support responsible energy consumption. An important part of this research focuses on motivating energy savings by providing feedback tools which present consumption metrics interactively. In this line of work, the configuration of feedback has been mainly discussed using cognitive or behavioral factors. This narrow focus, however, misses a highly relevant perspective for the design of technology that supports sustainable lifestyles: to investigate the multiplicity of forms in which individuals or collectives actually consume energy. In this article, we broaden this focus, by taking a phenomenological lens to study how people use off-the-shelf eco-feedback systems in private households to make energy consumption accountable and explainable. By reconstructing accounting practices, we delineate several constitutive elements of the phenomenon of energy usage in daily life. We complement these elements with a description of the sophisticated methods used by people to organize their energy practices and to give a meaning to their energy consumption. We describe these elements and methods, providing examples coming from the fieldwork and uncovering observed strategies to account for consumption. Based on our results, we provide a critical perspective on existing eco-feedback mechanisms and describe several elements for a design rationale for designing support for responsible energy consumption. We argue that interactive feedback systems should not simply be an end, but rather a resource for the construction of the artful practice of making energy consumption accountable.