Spring Forward

Well, we might use less energy for lighting once daylight savings time kicks in (and it does tonight -- well, Sunday morning), but the idea that DST "saves energy" is a myth. Earlier this year, Congress changed the timing of daylight savings time, and almost immediately, reports started that there wasn't a decrease in energy usage (I blogged about here back in April).

But the kicker was a well-organized study in Indiana. Prior to 2006, each county in Indiana determined individually whether to "join" the Daylight Savings Time change. So, about half the state did, and half didn't. I have to imagine that this caused some issues with towns a few miles apart having different times; I wonder how they handled that...

Anyway, the study compared before-and-after costs for all the counties in Indiana -- those that ahd previously not had extended DST and those that did. The change in energy usage was UP, not down -- primarily because of heating and cooling costs, not lighting. If you're up earlier in the dark and in the cold, the heat kicks on earlier, and in summer when you want to be indoors in the "evening", it's still warm outside. Makes sense, in a a common-sense sort of way.

Their finding was clear: The switch to daylight saving time cost Indiana homeowners dearly on their electric bills.

"Just in the state of Indiana, it turns out to be almost seven million dollars a year in increased residential electricity bills," Kotchen said. "And that's at a far lower price for electricity than the national average."

The study found that daylight saving time did save on lighting use but that heating and air-conditioning use more than offset any gains.

Now, DST may have other benefits -- I know that I, for one, like to come home when it's light outside and have those long evenings for leisure. Longer daylight hours in the afternoon may be better for people's moods, I don't know. But it's no longer a money-saving opportunity.

Similar results were shown in Australia in 2000, when some of the states in Australia extended daylight savings time to accommodate the Olympic games -- again, savings were nil. University of WA researcher Hendrik Wolf found that:

"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," Wolff said.

"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."

Well, Australia is probably not representative of the changes here, as the researchers are the first to admit, but the Indiana findings should at least suggest to the powers-that-be that we need to rethink the reason that we are shifting the clocks. The original reason for "summer time" was to take advantage of the long, well-lit evenings. The basis for the claims of energy savings come from a 1975 study that concluded that the US used about 1% less energy per day during the change. That study was contradicted by another done only a year later.

I think I see the problem. How many houses in 1975 had air-conditioning? That seems to be the primary cost effect now: cooling and heating costs, not lights. So the energy savings may well be evened out nationwide (I'm sure Arizona and Georgia use more air conditioning than Idaho and Maine in the summer, just as I'm sure that heating costs in northern Minnesota will be higher than those in the balmy south). But it is really necessary anymore? I still like the long summer evenings, and not being woken up at 4am is pretty nice: most people cite the summer nights as reason enough to continue the change. I'd have to agree with them.