Feedback as a means of decreasing residential energy consumption. Report PU/CES 34

When residential units are analyzed in human factor terms, it is apparent that the consumption level feedback (typically a bill, calculated once a month, over all appliances) is inadequate to give the resident useful information about his energy consuming actions. The present study tested the hypothesis that providing immediate feedback to homeowners concerning their daily rate of electric usage would be effective in reducing electric consumption. In the studied homes, central air-conditioning is the largest single source of electric power consumption during the summer. Accordingly, it was possible to predict the household's expected electric consumption in terms of the average daily outdoor temperature. Predicted electric consumption was derived from a previous month's modeling period during which a regression line was fitted to predict consumption from average daily temperature, for each home. Feedback was expressed as a percentage of actual consumption over predicted consumption. Feedback was displayed to homeowners four times a week for approximately one month. The results confirmed the prediction. Before feedback began, the feedback and control groups were consuming electricity at approximately equal rates. During the feedback period, the feedback group used 10.5 percent less electricity. The effectiveness of the feedback procedure was explained in terms of its cueing, motivational, and commitment functions