The changing relationships between producers and consumers

XV.4 July + August 2008
Page: 6
Digital Citation

COVER STORYChanging energy use through design

James Pierce, David Roedl

back to top 

When it comes to sustaining ourselves and the planet, nonrenewable energy and the looming consequences of global climate change are among the most critical issues of our time. In our view, interaction designers have the power and a responsibility to address them. While the creation of a renewable-energy economy and infrastructure is ultimately necessary, it is just as important that we rapidly reduce current consumption and shift cultural notions about the ways in which energy use affects our future. In the developed world, a view has long pervaded that treats energy as relatively cheap, abundant, and without significant consequence. Even as the public consciousness around climate change increases, this unsustainable conception persists. A new mental model is needed, and interaction designers can and should play a role in creating it. Computers and other digital products and systems consume enormous amounts of electricity. Moreover, it is daily interactions with the ecology of energy-consuming products that help construct our underlying conception of and relationship to energy in general [1].

Design efforts to conserve energy often focus on behind-the-scenes solutions such as efficient engineering (e.g., Energy Star) or automated energy management. Nonetheless, no matter how efficient an interactive product may be, a large portion of energy consumed by a digital product is often governed by user behavior. Interaction designers can actively promote conservation in use by taking human behaviors into account. Some products provide explicit feedback about energy consumption, such as the often-cited Toyota Prius dashboard. More often, interactive products conceal energy use or encourage wasteful behaviors in unintended, unanticipated ways. All energy-consuming products mediate relationships between humans and energy. Behaviors and expectations learned in present interactions affect attitudes and expectations in future ones. Designers need to ensure these relationships are designed with sustainable effects in mind.

Sometimes using less energy requires only small changes in behavior. At other times, it requires more radical shifts in lifestyles and values. When designing for sustainability in everyday life, we need to find ways to design products that both create needed behavioral and intellectual change and are easily adapted into daily routines. Finding ways to meet both of these criteria is among the most fundamental challenges for sustainable interaction design.

back to top  Critiquing Sustainable Interactions

In what follows, we reflect on six interactive designs that actively promote more sustainable interactions with respect to energy usage in the home. While similarly intentioned designs exist in many other domains, we feel that the domestic setting is an especially interesting space for interaction design in general, and for sustainable design in particular. Daily habitual interactions with technology in the home have the potential to influence one's behavior and attitudes in other contexts. Domestic space is also profoundly personal; objects must resonate with users on multiple levels to be acceptable. When they do, they often come to symbolize deeply held values of self. We have chosen six interesting exemplars, carefully selected from an original set of more than 30 products from 20 different companies and design teams. These six choices complement one another in their diverse qualities and approaches. Through these critiques we hope to illustrate some of the different ways in which designers have begun to promote energy conservation in use, with the goal of teasing out implications that may eventually contribute to the formation of a critical design framework.

As a starting point, we have loosely structured the critiques around five interaction qualities/ criteria, which are well-known concepts used in designing or evaluating designs within the HCI and interaction-design literature. We believe each interaction quality has potential value for designing to promote sustainability in use, and so we have framed the following open-ended questions to serve as impetus for criticism:

  • Persuasion. Does the product encourage formation of conservation goals and help users attain these goals by providing motivational cues and incentives?
  • Usefulness and Usability. Does the product encourage sustainable behaviors by making them easier, more convenient, and integrated with useful functionality?
  • Aesthetics. Does the product offer aesthetic value, such as pleasure, engagement, etc., that encourages sustainable interaction?
  • Symbolic Value. Does the product come to serve as a symbol of personal values and meaning, which encourages sustainable interactions?
  • Potential for Critical Reflection. Does the product stimulate critical reflection and discussion about issues related to energy and sustainability?

The following six critiques fall into two categories, namely (I) special products designed to monitor total energy use in the home, and (II) everyday products that have been reinterpreted to conserve energy during use.

back to top  Home Energy Monitors

While many people make some effort to conserve energy in the home, most have a limited sense of how much is being used at any given time. Electric meters are hidden outside or at least out of sight. For most the primary source of feedback about usage is the monthly utility bill, which is such an infrequent resolution that it is difficult to correlate to any specific factors. In recent years several digital products have emerged that seek to make feedback about patterns of usage part of everyday domestic experience. Many of the off-the-shelf products of this nature come from the U.K.; two examples are the Eco-eye and the Wattson.

The Eco-eye works by means of a sensor attached to a home's electric meter that transmits wirelessly to a portable display unit. The display unit, which can be wall-mounted or freestanding, shows the current energy being used either in kilowatts or in terms of projected monetary costs. There are two primary ways to interact with the Eco-eye. For someone with a strong curiosity about his or her consumption, the device can be actively used to perform an energy audit of the home. To do so, the user can carry the display around and turn appliances on and off, thus determining the particular usage of each appliance. In this way the Eco-eye facilitates analysis. It provides useful and otherwise unavailable information that can help users achieve conservation goals by, for example, deciding which appliances to use or not use and for how long.

An alternative, more passive use of the Eco-eye is to mount the display on a wall and glance at it periodically to check the consumption level. Used in this way, it serves as a persistent visual reminder not to waste energy. Noticing the monetary cost rise can be an additional persuasive incentive to change one's behavior. Experientially, the design is more functional than aesthetic. While there is likely reassuring pleasure in knowing when monthly costs are low, the boxy white form factor and gray digital display are very utilitarian; its appearance is not likely to complement the average living room decor. This may discourage users from keeping it on display and taking full advantage of its visual cues. In any case, the Eco-eye provides useful functionality to those with a strong motivation to reduce their energy consumption.

Functionally, the Wattson is very similar to the Eco-eye, yet unique elements of its user experience may significantly change the way people use the product. Like the Eco-eye it can be carried around the home to perform an active energy analysis. However, its unique design also makes it especially suitable for stationary positioning and prominent display. The sleek form attractively blends in with the other domestic objects and allows the device to sit upright or horizontally. In addition to the colored numerical display, Wattson has a color-changing "mood light" that casts a glow on surrounding objects. With different light emitted from each side and two positioning options, the Wattson invites users to let playful placement around the house help them determine their most aesthetic and functional configuration.

The mood light pulses and changes color along a spectrum from blue to red, communicating energy usage in an ambient fashion that demands no direct attention from the user. One need be only peripherally aware of the device to notice its color change as a visual cue that usage levels are high. The color also adds a subtle evaluative measure in that the shade implicitly makes a claim about the relative goodness of the consumption level (i.e., blue is good, red is bad). With its combination of form and light, the Wattson can seamlessly integrate with its setting and yet evoke interest. The novelty of this ambient energy awareness may stimulate reflection, behavioral change, and conversation. Because of its aesthetic value, the Wattson also has potential to become an enduring part of peoples' home ecology and achieve sustainable longevity of use.

back to top  Reinterpreted Everyday Products

The following products are familiar objects that have been redesigned, promoting energy conservation during use. Whereas home energy monitors are novel products with core functionality related to energy conservation, these designs have other primary uses. The strategies they employ to promote sustainable interaction are diverse. The Belkin Conserve stays close to its traditional functionality, while the other designs more radically redefine the user experience with respect to energy.

The Belkin Conserve power strip can be turned on and off via a large wireless-remote switch. It is primarily through its usefulness and usability that it encourages energy-saving behavior. For functional and aesthetic reasons, people typically place power strips out of view and out of reach. Consequently, many devices stay on because the on/ off switch is hard to reach. The Conserve offers convenience: The simplicity of the switch's operation and form combine to encourage its use. It also provides useful and usable functionality for the user who is not conservation-minded. For example, anyone may find it useful to be able to remotely turn off his or her lamp at night. In doing so, other devices plugged into the Conserve may be turned off at the same time, regardless of whether the individual is aware of it. Hence, the person may not realize she or he is saving energy by turning off lamps and other devices that may be consuming phantom power [2]. Because the Conserve is a functional, logical combination of light switch and power strip, it seems unlikely to gain symbolic value or stimulate critical reflection about energy or sustainability. Rather, it will more likely be integrated into daily routines without actually raising awareness of the potentials for increased sustainability of use. The Conserve is useful and accessible to everyone, including those with physical disabilities. Through its functionality the Conserve gives more control back to its owner, who will likely use it in sustainable ways (whether or not she or he cares about sustainability).

According to the Potenco website, "a minute of pulling the PCG generates enough energy for 20 minutes of talk time on a mobile phone, one hour of ultrabright LED flashlight use, [and] three hours' play time on an iPod Shuffle [3]." The Potenco Pull-Cord Generator (PGC) was specifically designed for use with the XO laptop [4]. It does not provide explicitly persuasive information, but because it is useful and convenient to remotely power digital devices by hand, it encourages hand powering rather than plugging in. The cost of energy is made immediate and tangible. As a result, one is more likely to conserve energy by shutting down devices when not in use. Moreover, it may be preferable to downgrade to extremely low-power devices such as the XO because the PCG does not generate enough energy to power a standard laptop [5]. In the case of the XO, nice-to-have functionality is sacrificed for the most essential functionality, along with the comfort and satisfaction of knowing that one's bodily power alone can sustain it. Regularly engaging with the PCG may create an intimate relationship between the individuals, their devices, and their energy. A certain delight results from the playful interaction and the immediate feedback of watching a device come to life from your own power. The PCG seems likely to evolve symbolic value through use, representing self-sufficiency and sustainability. The PCG raises critical questions about what we truly need and desire from our digital devices. The PCG and XO were designed for the developing world, which lacks reliable access to electrical power, yet people in the first world also desire these products. Many products we use in our daily lives assume an abundance of cheap energy, which invites unrestricted use without thought of harm. The Potenco PCG can make people aware of the human energy required to power electric devices, prompting thoughtful use.

The Element is an adjustable electric radiator constructed from 35 60-watt incandescent lightbulbs, which provide the heat source; the light emitted is directly related to the amount of heat produced and energy consumed. The designers note that "direct feedback...[may]... help consumers build conceptual models of how energy-consuming devices behave in different situations making the perception of electricity less abstract [6]." The visual feedback from the light-bulbs provides information that may help users better understand how the radiator works at an engineering level. For example, over time one may notice that cranking the thermostat setting all the way up does not cause the lights to glow brighter more quickly (since a thermostat is actually a switch, not a valve). The user may possibly make this connection and change her or his behavior by setting the dial to the desired temperature, rather than overcompensating, thus saving energy. This feedback can also act as a persuasive prompt. During user studies conducted by the designers, "some participants said [the Element] would be useful as an indicator of changes in the domestic climate such as open windows and function as a reminder of it being on or off." The Element's aesthetic form and engaging interactions do not directly reward sustainable behavior, but rather they entice the user to explore and interact with it, stimulating critical reflection. As inspiration for their design, the designers acknowledge Verbeek and Kockelkoren's concept of engaging objects, which "move underlying operations of objects to a visible level and make users part of the functional processes." The Element encourages active engagement from users and makes its inner workings transparent [7]. In doing so it may encourage sustainable usage and prompt the individual to think more deeply about the relationship between energy and use. In spite of its useful feedback and aesthetic appeal, it is unlikely to be used as a functional product. Still, the Element is a valuable source of knowledge for designers and the public—offering a critique of dominant approaches to design and suggesting new directions for the design of more pleasurable, meaningful, and sustainable everyday products.

As described by its designers, "the Energy Curtain is a window shade woven from a combination of textile, solar-collection and light-emitting materials [8]." Traditionally, the primary function of curtains is to regulate light. The Energy Curtain does not provide any additional usefulness or usability, nor does it provide any persuasive information. It does provide aesthetic value: "During the day, the shade can be drawn ... and, during the evening, the collected energy is expressed as a glowing pattern on the inside of the shade." However, this aesthetic reward can actually subvert the functionality of the curtain and discourage sustainable behavior. Closing the curtain during the day will cause the room to darken, possibly requiring the use of artificial lighting. The energy curtain thus forces the user to decide between either using natural light and not being rewarded with the glowing pattern, or using artificial light and being rewarded. Designed to provoke critical reflection, the Energy Curtain "introduces a conceptual twist and requires that a user act tangibly on the choice between consuming or saving energy [1]." This conflict between aesthetics and functionality creates the opportunity for para-functionality, "a form of design where function is used to encourage reflection on how electronic products condition our behavior [9]." In particular the Energy Curtain can provoke the realization of how design estranges us from the natural energy of the sun, renders energy abstract and intangible, and hides the energy costs of our actions. Materially and experientially woven into domestic life, the Energy Curtain can stimulate conversation within the home and serve as an ever-present symbol of newly appreciated relationships between actions, products, and consumption. The Energy Curtain exemplifies how aesthetics, functionality, para-functionality, and symbolic value can coexist in a single design, leading to beautiful, functional, and meaningful products that may in the long term lead to more environmen tally sustainable values and behaviors.

back to top  Design Questions to Keep in Mind

These examples illustrate valuable approaches to designing interactive products that promote more sustainable use of energy or reflections on sustainable design and use of interactive products. They also raise questions regarding the challenges to overcome:

  • Adoption. Who will adopt these products and why? Some products, like the Eco-Eye and Wattson, explicitly address issues of conservation and sustainability, while others, like the Belkin Conserve and Potenco Pull-Cord Generator, focus more on improving existing functionality.
  • Durability. Will these products continue to be useful over time? Will people grow attached to them because of their aesthetic, reflective, and symbolic value? Long term, will the Eco-Eye and Wattson continue to offer useful and persuasive information? Will people dispose of the Belkin Conserve or the Pull-Cord Generator when more useful and stylish models come out?
  • Effectiveness. Will these products lead to local behavior changes or more holistic changes in lifestyles and values? Will they lead to immediate savings in energy, as the Belkin Conserve does? Or can they encourage more thoughtful interactions beyond immediate use, such as the Energy Curtain, which locally may actually discourage sustainable interactions in order to create reflection? From a cost-benefit perspective, is it worth introducing a particular product into the world in hopes of getting us to use less?
  • Innovation. Do these products support existing paradigms of energy usage, such as the Belkin Conserve or Eco-Eye, or do they suggest more radical interaction paradigms, such as the Pull-Cord Generator, the Element heater, or the Energy Curtain, which seek to more dramatically redefine relationships between people and energy?

As designers and citizens of this planet, we need to carefully consider what we do and do not want to sustain. Design, of course, creates both problems and solutions. There is something both ironic and troubling in our compulsion to design more new devices rather making do with old ones in hopes of doing less harm to the planet. As we design for sustainable interactions and experiences, we should always be looking for ways to "do less with design" [10], a consideration perfectly embodied by Scott Amron's Die Electric experiment [11].

back to top  References

1. This perspective is inspired by work of the STATIC! group at Interactive Institute, Ivrea. Backlund, S., M. Gyllenswärd, A. Gustafsson, S.I. Hjelm, R. Mazé, and J. Redström. "STATIC! The Aesthetics of Energy in Everyday Things." Paper presented at the DRS Wonderground Conference, Lisbon, Portugal, November 2006.

2. Phantom power (standby power, idle current, vampire power, and wall warts) refers to power consumed by electronic devices when they are switched off, in standby mode, or are otherwise consuming electricity without performing any useful function requiring power. Three to 10 percent of residential electricity is attributed to standby power, according to recent estimates. Bertoldi, P. et al. "Standby Power Use: How Big is the Problem? What Policies and Technical Solutions Can Address It?" Proceedings of the 2002 ACEEE Summer Study on Energy Efficiency in Buildings. (2002).


4. The XO, which has been referred to as the "$100 Laptop," is an inexpensive laptop computer designed and distributed by the One Laptop Per Child (OLPC) organization for children in developing countries around the world.

5. According to the OLPC website, the XO "consumes less than two watts—less than one-tenth of what a standard laptop consumes."

6. Gyllensward, M., Gustafsson, A., and M. Bang. "Visualizing Energy Consumption of Radiators" In Persuasive Technology. Berlin: Springer Berlin / Heidelberg, 2006.

7. Verbeek, Peter-Paul. What Things Do: Philosophical Reflections On Technology, Agency, And Design. University Park, PA: Penn State University Press, 2005. Verbeek proposes transparency and engagement as design strategies for improving the material aesthetics of products in order to facilitate product attachment.


9. Dunne, Anthony. Hertzian Tales: Electronic Products, Aesthetic Experience and Critical Design. Cambridge, MA: MIT Press, 2005.

10. The phrase "do less with design" owes to the title of a public presentation by Eli Blevis.


back to top  Authors

James J. Pierce is a master's student in the human-computer interaction/ design program at Indiana University and a member of the Sustainable Interaction Design Research Group. Currently, his research interests are focused on the areas of sustainable interaction design and interaction criticism. For more information, visit

David Roedl is a master's student in the human-computer interaction/design program at Indiana University and a member of the Sustainable Interaction Design Research Group. His current work focuses on the design of interactive data visualizations as a means to motivate environmental responsibility. For more information, visit

back to top  Footnotes


back to top  Figures

UF1Figure. The Wattson home energy monitor

UF2Figure. The EcoEye home energy monitor

UF3Figure. The Belkin Conserve power strip

UF4Figure. The Potenco Pull-Cord Generator

UF5Figure. The Energy Curtain

back to top 

©2008 ACM  1072-5220/08/0700  $5.00

Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee.

The Digital Library is published by the Association for Computing Machinery. Copyright © 2008 ACM, Inc.

Post Comment

No Comments Found