Late? Feel good; you might be saving energy

Bob Tippee

If you're late for an appointment Mar. 12, blame Congress, but feel good about yourself. You might be—cue the violins—saving energy.

The Energy Policy Act of 2005 added about 4 weeks to Daylight Savings Time (DST). This is supposed to—cue the violins again—lower energy consumption.

DST now starts on the second Sunday of March instead of the first Sunday of April and ends on the last Sunday of October instead of the first Sunday of November. Clock time advances by 1 hr on Mar. 11.

While computers, servers, and various gadgets with internal electronic clocks need adjustment, experts say the change warrants no revival of Y2K anxiety.

The idea is to shrink the period during which people need lighting. But will that really—violins, please—lower energy use?

California has studied DST and energy use much recently. Last month, a staff paper by Adrienne Kandel, in the Electricity and Demand Analysis Division of the California Energy Commission, raised doubts.

"There is no clear evidence that electricity will be saved from the earlier start to [DST] on Mar. 11, but the 7 p.m. peak load will probably drop on the order of 3% for the remainder of March, lowering capacity requirements," Kandel concluded from simulations of Californian energy-use patterns. Extending DST by a week into November would have similar but smaller effects. Capacity constraints, she added, "usually do not occur in March and early November."

With earlier DST California might, Kandel said, save "a fraction of a percent of total electricity use" unless a morning electricity spike offsets the effect.

Apparently unsure about the nationwide effectiveness of its DST tinkering in the energy bill, Congress ordered the Department of Energy to do a quick follow-up study.

Whether or not the initiative proves to have worked, date and time processing functions need changing in all electronics in or related to the US. And among those sure to be overlooked may well be the one you need for a reminder to be somewhere important on time.

If catastrophe happens, however, remember: In partnership with Congress, you—one more time on the violins, crescendo—saved energy. Or not.

(Online Mar. 2, 2007; author's e-mail:

To access this Article, go to: