Does Daylight Saving Time Reduce Energy Use?
Coloradans will be able to enjoy an extra hour of sleep Saturday night. Daylight saving time officially ends at 2 a.m. Sunday morning, with the exception of Arizona, Hawaii and some U.S. territories.
The concept of saving daylight hours was first penned by Benjamin Franklin, although it wasn't seriously proposed until 1907 in an essay written by London builder William Willet. Since World War I, the majority of Americans have observed the time changes in some form or another. President Lyndon Johnson was the first to sign a bill with national daylight saving time standards.
The Energy Policy Act of 2005 [.pdf] extended daylight saving time beginning in 2007 in an effort to save energy, the theory being that people would spend more time outside. Now the standard is to drop an hour the second Sunday of March and add an hour the first Sunday of November, adding roughly a month to the daylight saving time schedule.
One year after the new policy was enacted, the U.S. Department of Energy [.pdf] released results from a study, revealing a 0.5 percent reduction in energy use during the extended daylight saving time period. That's enough power to provide energy for 122,000 average homes in a year.
But the data isn’t conclusive.
Another study focused on Indiana, a state which didn’t observe daylight saving time until 2006. The scientists found that while lighting costs were reduced, there was an upsurge in people’s consumption of power through other appliances like air-conditioning units.