Daylight Saving Time: A True Energy Saver?
We here at the Alliance hope that everyone has recovered from “springing forward” this weekend—Daylight Saving Time can be a drag first thing on Sunday morning after clocks change, but we always promptly forget that once the sun stays up past 6:00pm.
Many people believe that we change the clocks to help farmers, but in actuality Daylight Saving Time was first adopted in the U.S. during World War I as a means to save electricity. Longer evenings allow for more summer barbecues and wiffle ball games, but does Daylight Saving Time really save any energy?
Department of Energy: Yes
The Energy Policy Act of 2005 increased the portion of the year that was subject to Daylight Saving Time, adding approximately four weeks of additional daylight in the evening. A 2008 DOE report found that U.S. electricity use was reduced by 0.5% for each day of extended Daylight Saving Time, adding up to a total of 1.3 billion kilowatt-hours in electricity savings—the amount of electricity used in 100,000 households in one year.
The report found that electricity savings in the evenings more than made up for small increases in electricity usage in the mornings. DOE also determined that changes in national traffic volume and gasoline consumption were statistically insignificant, and could not be attributed to the extended Daylight Saving Time.
Indiana and Australia Studies: No
A study in Indiana, on the other hand, had completely different results. Daylight Saving Time was instituted statewide in 2006—before that, the decision to practice DST was made on a county-by-county basis. Researchers looked at monthly electricity billing information for the majority of households in one part of the state between 2004 and 2006, and found that Daylight Saving Time resulted in a one percent overall increase in residential electricity demand. They also found that DST causes the greatest increase in electricity consumption in the fall, some two to four percent before households “fall back.” The report estimated that Daylight Saving Time costs households across the state an annual $9 million in increased electricity bills.
A similar situation arose in Australia in 2000, when Sydney hosted the Olympics; typically three of Australia’s states observe Daylight Saving Time beginning in October, but two of the states began DST two months earlier that year to facilitate the Olympics. Researchers compared electricity usage data in the two states and found that while extending Daylight Saving Time reduces electricity consumption in the evening, these benefits are cancelled out by increased consumption in the morning.
It seems that the verdict is still out on the contentious issue of energy savings from Daylight Saving Time. Whether or not you save energy likely also has much to do with where you live; those who live in warmer climates and use more air conditioning are much less likely to see any electricity savings from Daylight Saving Time.
Either way, changing your clocks can also serve as a good reminder to change the batteries in your smoke and carbon monoxide detectors. And as long as you have a ladder out, why not also change a few of your light bulbs to much more energy-efficient halogens, CFLs, or LEDs? That’s one way to be sure that you’ll save some energy (and money) this Daylight Saving Time.