By Richard Romano
Published: November 6, 2012
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.