How customers interpret and use comparative graphics of their energy use.

Comparative energy information is one method energy policymakers have employed to motivate consumers to reduce their energy use. The US appliance labeling program, for example, has used graphical displays to illustrate the differences in energy consumption among home appliances. Little is known, however, about how consumers interpret various graphical displays and/or how they use the information. Additionally, subtleties in the accuracy with which these graphical displays convey the underlying data have yet to be addressed in the research literature. This paper presents research on interpretation of graphical displays developed and tested by University of Delaware's Center for Energy and Environmental Policy under a cooperative agreement with the United States Environmental Protection Agency. The objective oftl1e research is to provide utilities with tools that improve customers' ability to: (1) evaluate their energy use relative to otl1ers and (2) to measure the effects of tl1eir own efficiency efforts. Drawing upon the results of semi-structured interviews and a mail survey, we discuss tl1e relative strengths and weaknesses associated with alternative display options. We have identified a number of problems with existing methods of presenting energy information in the areas of: (1) customer interpretations of the graphical displays and (2) their accuracy and reliability. We conclude with some suggestions as to how further research could address and overcome these problems.