The List’s quest to understand this strange phenomenon we call daylight saving time has culminated in one seemingly simple question: Does daylight saving time accomplish what it was established to do, which is save energy? This question has led The List to a sticky intersection between science and politics, two topics she generally finds baffling. An attempt to clear the air on the energy efficiency of daylight savings.
Daylight saving time first proposed as an energy-saving measure by Ben Franklin
Who believed that far too many candles were being wasted in the summer evenings. Debate continues about whether or not Franklin was kidding.
The belief that DST would save energy bolstered by 1970s study
Conducted by the Dept. of Transportation, this is the report that Yale professor Matthew Kotchen says that “everyone refers back to, even though the results are questionable.” A review of the research by the National Bureau of Standards later found that the results were not significant, but the sense that DST would save energy was already cemented in the public imagination.
Congress passes energy bill that extends DST in 2005
Stuck in the Energy Policy Act of 2005 was a provision extending daylight saving time by a month. Because it was an amendment, it was not debated in Congress. It called for a study to be done on whether the extension would save energy.
As Indiana moves to uniformly adopt DST, professor Matthew Kotchen decides to study energy use in the state
Because some counties observed DST and others didn’t, Indiana provided the perfect opportunity for Kotchen and PhD student Laura Grant to examine the effects of DST on energy use in southern Indiana.
Energy use does not go down when DST is introduced—it goes up
After looking at the years before and after it went into effect and comparing energy consumption between counties that had previously had DST and counties where it was new, the researchers found that Indianans increased their energy use during daylight saving time by 2 percent. That equals $9 million in increased utility bills.
People turn on lamps less but AC more
Increased air conditioning use in the summer negated the decrease in energy used for lighting, says Grant.
The Dept. of Energy comes out with its own study saying that the DST extension saves energy
Kotchen, who was not a part of the study, says that the savings found by the report were “very modest” and that he doesn’t understand some aspects of the study, including the methodology. “Not that I have such keen insights,” he adds, “but someone like myself should be able to understand their methodology.” Kotchen was clear that he does not think there was anything “malicious” about the study. Says Laura Grant: “We found some things we would question. Looking into it deeper, I think there are some things that could be improved.”
Dept. of Energy researcher stands by study
David Belzer of Pacific Northwest National Laboratory and one of the authors of the DOE study disputes the idea that because his results differ from Kotchen and Grant's, one of them must be wrong. He cites the differences in time frame and scope between the two studies--the Dept. of Energy study examined utilities consumption across residential, commercial, and industrial users, whereas the Indiana study looked at residential only. Belzer stands by his results and says, "I don't think one can say to what extent DST would have impacted total energy use in Indiana."
Kotchen and Grant do not hate DST
Grant says she doesn’t blame Indiana officials for pushing the state into uniformly observing DST. “I’d say you did it for the right reasons,” she says. “You did it for coordination efforts.” Says Kotchen: “I think there’s a lot of reasons to have daylight saving time. Lots of people like it. But I think it’s time to stop saying it saves energy.”
But the happiness brought by daylight saving time is immeasurable!
The office of Congressman Ed Markey, the Massachusetts Democrat who co-authored the extension, did not return a request for comment, but Markey’s website makes his position clear: “We can’t count the accumulated smiles from an extra hour of sunshine, but we can count the dollars.” He’s definitely right about the smiles.