How Good Are You At Understanding and Saving Energy?

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BY JACK DINI – What’s the most effective thing you could do to save energy? When asked this question during a recent survey, 20% of the respondents said that they could turn off the lights. Wrong! Lighting accounts for a relatively small proportion of the average person’s energy use and almost all of us could save far more energy in other ways—for instance by turning the heating down as little as a single degree. (1)

What about glass versus aluminum containers? Which requires the most energy? If you said glass you were correct but most folks in the survey didn’t. Glass requires so much energy to make—or recycle—that it is always more eco-friendly to use aluminum cans, even if one is talking about virgin cans compared to recycled bottles. Making a glass container from virgin material uses 40 percent more energy than making an aluminum one, and 2,000 percent more when recycled material is used. (2)


Another behavior which people commonly consider to be energy-virtuous is the unplugging (or switching off at the wall) of appliances on standby or unused cell-phone chargers. This is an even bigger waste of time than switching off lights. A modern TV on standby uses less than a watt of power. As Lewis Page reports, “You would need to unplug it or switch it off for a year to save as much energy as it takes to have one-and-a-half baths.” (3)

These revelations are in a report from the Earth Institute at Columbia University analyzing responses made by Americans in 34 states. Researchers Shahzeen Attari and colleagues conducted an on-line survey of 505 participants on 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. (1)

“Perhaps the killer revelation from the survey is that it is, in fact, the very people who are keenest and most active about reducing their energy consumption who are the most ignorant. Participants who engaged more in energy-conserving behaviors had less accurate perceptions of energy use and savings, possibly reflecting unrealistic optimism about the effectiveness of their personal energy-saving strategies compared with alternative ones,” notes Lewis Page. (3)

Lighting represents about 8.8 percent of the electricity we use in the US. We use 35.5 percent of our electricity just for cooling things off—air conditioning, refrigerators and freezers. We use another 10.1 percent for heating (most homes are heated by natural gas), and another 9.1 percent to heat water. (4)

So What Can One Do?

Gerald Gardner and Paul Stern identified a short list of the most effective actions US households could take to decrease their contributions to climate change. They concluded that by changing the selection and use of household and motor vehicle technologies, households could reduce their energy consumption by nearly 30%–without waiting for new technologies, making minor sacrifices, or losing a sense of well-being.

They provide a list of effective actions that can be taken. In the transportation category, items including carpooling, getting frequent tune-ups, avoiding sudden acceleration and stops, combining errand trips to one-half current mileage, cutting highway speeds from 70 to 60 mph and maintaining correct tire pressure, adds up to 17.6 percent potential energy savings. (5)

Inside the home, replacing 85 percent of all incandescent bulbs with compact fluorescent bulbs, turning down the thermostat from 72F to 68F during the day and to 65F at night, turning up the air conditioning thermostat from 73F to 75F and using only warm (or cold) wash for clothes saves a potential 8.6 percent energy.

The two biggest-ticket items include buying more fuel-efficient cars (30 versus 20 mpg EPA average-adjusted composite) and installing or upgrading attic insulation. These can save more energy than all the other items mentioned above. (5)


  1. Shahzeen Z. Attari, et al., “Public perception of energy consumption and savings,”, July 12, 2010
  2. “Survey says: many are still clueless on how to save energy,”, August 17, 2010
  3. Lewis Page, “People have NO BLOODY IDEA about saving energy,”, August 18, 2010
  4. Laurence Gonzales, Everyday Survival, (New York, W. W. Norton, 2008), 2002

Gerald T. Gardner and Paul C. Stern, “The short List: The most effective actions US households can take to curb climate change,” Environment Magazine, 50, 12,

Jack Dini is a resident of Livermore, CA