Washington, March 10 : Studies by environmental economists have suggested that saving daylight time actually has consumers using more power and paying bigger energy bills.
Daylight saving time (DST) is the convention of advancing clocks so that afternoons have more daylight and mornings have less. Typically, clocks are adjusted forward one hour near the start of spring and are adjusted backward in autumn.
This method has been widely touted as a way to save energy.
But, according to a report in the National Geographic News, Hendrik Wolff, an environmental economist at the University of Washington in Seattle, is skeptical of the purported savings.
Wolff and colleague Ryan Kellogg studied Australian power-use data surrounding the 2000 Sydney Olympics, when parts of the country extended daylight saving time to accommodate the games.
The pair compared energy use in the state of Victoria, which adopted daylight saving time earlier than normal, to South Australia, which did not.
"Basically if people wake up early in the morning and go to bed earlier, they do save artificial illumination at night and reduce electricity consumption in the evening," said Wolff.
"Our study confirmed that effect. But we also found that more electricity is consumed in the morning. In the end, these two effects wash each other out," he added.
A researcher - Matthew Kotchen, who is an economist at the University of California, Santa Barbara, found a similar case in the state of Indiana in the US.
Using the quirky chronology of Indiana's daylight saving time history, he measured the time change's energy impact in that state.
When the entire state adopted daylight saving time in spring 2006, Kotchen and colleague Laura Grant were able to observe changes in energy use in homes throughout southern Indiana over a three-year period. "Just in the state of Indiana, it turns out to be almost seven million dollars a year in increased residential electricity bills," said Kotchen. "And that's at a far lower price for electricity than the national average," he added.
The study found that daylight saving time did save on lighting use but that heating and air-conditioning use more than offset any gains.
"At least in southern Indiana, and probably in other places that have a similar climate, it's resulting in an increase in residential electricity consumption. Our estimates range between one and four percent," said Kotchen.
On March 9, people in the United States rolled their clocks forward an hour at 2 a.m. and begin the country's second consecutive year of extended daylight saving time.