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Falling Back

By on November 6th, 2012

If you were an hour ahead of everyone yesterday, blame it on not “falling back” Sunday morning, as Daylight Savings Time officially ended last weekend. Every spring and fall, debates pop up over the efficacy of DST and whether it makes sense from an energy conservation standpoint, or if it’s just an anachronism, a throwback to a time when we were all farmers. (Actually, DST was never an agricultural policy, and farmers were never all that gung ho about it.)

Although I usually spend the day after the time change experiencing a kind of “jet lag” (but then I get jet lag when I fly from New York to Florida, so maybe it’s not the time change that’s the problem), it is psychologically easier to get up when it is light out, which was one of the reasons the idea was first proposed. (The idea, as with so many others, originated with Benjamin Franklin, in an essay titled “An Economical Project for Diminishing the Cost of Light,” published in the Journal de Paris in April 1784. However, it was actually intended to be more humorous than practical, not quite up there with Swift’s “A Modest Proposal,” but still…)

Brit William Willett re-suggested the idea of some sort of daylight savings in 1907, inspired (or aggrieved, I guess) by his noticing that houses had their shades down even though the sun was shining. (Consider him the Gladys Kravitz of the early 20th century.) Anyway, he wrote a pamphlet—what would no doubt be a blog post today—called “The Waste of Daylight” in which he (get this) proposed “to move the clock ahead by 80 minutes in four moves of 20 minutes each during the spring and summer months.” Yeah, that would have gone over like gangbusters. The idea continued to have life and “British Summer Time” (not a song by The Kinks) was created by an Act of Parliament in 1916, and clocks were set forward one hour during the summer months. England discovered that this clock change saved energy, and came in especially helpful during the First World War—and the U.S, followed suit during WWI. However, it was not very popular, and was repealed after the war was over. Daylight Savings Time was reinstated in the U.S. in 1942 during the Second World War, and was repealed again in 1945.

During the next 20 years, there was no national policy in the U.S. regarding Daylight Savings Time; states and municipalities were free to do whatever they liked. Needless to say, this caused a great deal of confusion, particularly in the transportation and broadcasting industries. (It still can cause confusion, especially when parts of Indiana and Arizona did not observe DST.) So The Uniform Time Act of 1966 established what we now know of as Daylight Saving Time. Still, though, any area that wanted to exempt itself from Daylight Saving Time could do so. Over the years, the start and stop dates of DST have been tweaked, ostensibly in the name of saving energy.

But that’s just it. Does DST actually save energy? That’s not entirely clear.

Dr. David Prerau, author of Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time, explained… “It’s been found to reduce energy usage by doing something called load smoothing”—separating out electrical loads throughout the day to better deal with the valleys and peaks of energy usage—“and so you’re going to generate energy more efficiently and therefore have less effects on pollution.” A study by the U.S. Department of Transportation showed that the country’s electricity usage is cut by 1 percent each day because of daylight saving time.

However,

Michael Downing, a teacher at Tufts University and the author of Spring Forward: The Annual Madness of Daylight Saving Time, says messing with the clock doesn’t really save energy. “Daylight saving is still a boon to purveyors of barbecue grills, sports and recreation equipment and the petroleum industry, as gasoline consumption increases every time we increase the length of the daylight saving period,” Downing tells MNN. “Give Americans an extra hour of after-dinner daylight, and they will go to the ballpark or the mall—but they won’t walk there.”

A 2007 report by the California Energy Commission found that, “The extension of daylight saving time (DST) to March 2007 had little or no effect on energy consumption in California.”

Another interesting study came from Indiana, which in 2006 required that all counties observe Daylight Savings Time. So researchers were able to look at electricity consumption over a number of years before and after the policy change. Their conclusions:

Nevertheless, there is surprisingly little evidence that DST actually saves energy. This paper takes advantage of a natural experiment in the state of Indiana to provide the first empirical estimates of DST effects on electricity consumption in the United States since the mid-1970s. Focusing on residential electricity demand, we conduct the first-ever study that uses micro-data on households to estimate an overall DST effect. The dataset consists of more than 7 million observations on monthly billing data for the vast majority of households in southern Indiana for three years. Our main finding is that—contrary to the policy’s intent—DST increases residential electricity demand. Estimates of the overall increase are approximately 1 percent, but we find that the effect is not constant throughout the DST period. DST causes the greatest increase in electricity consumption in the fall, when estimates range between 2 and 4 percent. These findings are consistent with simulation results that point to a tradeoff between reducing demand for lighting and increasing demand for heating and cooling. We estimate a cost of increased electricity bills to Indiana households of $9 million per year. We also estimate social costs of increased pollution emissions that range from $1.7 to $5.5 million per year. Finally, we argue that the effect is likely to be even stronger in other regions of the United States.

Still, it’s nice to get up when it’s light out.

  1. 2 Responses to “Falling Back”

  2. By Emily on Nov 6, 2012 | Reply

    But it is so NOT nice to be slammed all at once into darkness for the commute after work. I would gladly do away with DST.

  3. By michael jahn on Dec 4, 2012 | Reply

    When my kids were little, i liked that they could walk to the bus stop when it was light out, as opposed to walking in the dark.

    Other than that, not a fan, but that was reason enough to be okay with it.