For every late arrival, brunch missed, or precious bit of weekend downtime lost when we turn the clocks ahead an hour for Daylight Saving Time (DST) in the spring, we’ve been able to take comfort in knowing it’s been for the sake of saving electricity.

The US implemented DST on and off throughout the 20th century, beginning with WWI, as a means to save energy.

But at least one study questioned the worthwhileness of all that effort, suggesting that Daylight Savings doesn’t reduce energy consumption but actually increases it.

Setting clocks ahead means more daylight during working hours and therefore less need to switch on the lights and use electricity.

However, researchers at the University of California Santa Barbara found that in Indiana, where they compared electricity use between counties that adhered to and forewent DST, the former group actually increased their energy consumption by 1 to 4 percent.

“We estimate a cost of increased electricity bills to Indiana households of $8.6 million per year. We also estimate social costs of increased pollution emissions that range from $1.6 to $5.3 million per year.”

What’s the catch? While people may keep their lights on less, they turn their air conditioners and heaters on more. An extra hour of light can lead to an uncomfortably warm house after working hours on an Indiana summer day. And likewise, a dark and cold house in the morning before work in the winter can cause people to turn up the heat.

Herein lies the study’s caveat: the weather in Indiana can’t necessarily be extrapolated to the rest of the country. Which leads to the next conundrum. Despite that DST is billed as an energy-saving measure, very few conclusive studies on its effectiveness have been conducted, according to the researchers.

Given all the media and talk this study has stirred up, combined with the pressures of climate change, we may just see a few more studies springing up. In the meantime, remember to set your watch...cell phone, computer, PDA, iPod, car clock, microwave, and bedside alarm.

This article originally appeared in "Plenty" in March 2008.

Copyright Environ Press 2008

Does daylight saving save energy?
Indiana is actually upping energy use during DST, as opposed to reducing.