This is the finding of a new study called "Public perceptions of energy consumption and savings" published in the Proceedings of the National Academy of Sciences. The study's authors say that people underestimate the energy saving potential of big changes – like driving a more efficient car – and overestimate the impact of little things like turning off lights. One slightly surprising finding: respondents with "stronger proenvironmental attitudes" understood energy savings better than others.
From the study's opening summary:
Oh, can anyone help us understand the chart above? Our math skill aren't up to it (j/k)In a national online survey, 505 participants reported their perceptions of energy consumption and savings for a variety of household, transportation, and recycling activities. When asked for the most effective strategy they could implement to conserve energy, most participants mentioned curtailment (e.g., turning off lights, driving less) rather than efficiency improvements (e.g., installing more efficient light bulbs and appliances), in contrast to experts' recommendations. For a sample of 15 activities, participants underestimated energy use and savings by a factor of 2.8 on average, with small overestimates for low-energy activities and large underestimates for high-energy activities. Additional estimation and ranking tasks also yielded relatively flat functions for perceived energy use and savings. Across several tasks, participants with higher numeracy scores and stronger proenvironmental attitudes had more accurate perceptions. The serious deficiencies highlighted by these results suggest that well-designed efforts to improve the public's understanding of energy use and savings could pay large dividends.
[Source: Proceedings of the National Academy of Sciences via Earth Institute and Green Car Congress]
The graph plots the perceived vs. actual energy saved (in watt hours) of three common automobile-related items. When reducing speed from 70 miles per hour to 60 for 60 miles, people surveyed thought you saved around 70,000 Wh when you actually save around 10,000 Wh. The perceived value of driving a car that gets 30 mpg instead of 20 for an hour was also around 70,000 Wh, but the actual energy savings are 50,000 Wh. Lastly, tuning up your car twice a year was thought by respondents to save you 100,000 Wh but it really can save you ten times that (1,000,000 Wh).