Monday, March 12, 2007

Daylight savings

Mud season has begun (and if you're not from the northeastern USA, here's the wikipedia article).

This past weekend was also the start of the new daylight savings time, which itself was a product of the Energy Bill of 2005. Back in the mid-1970s, Daylight Savings supposedly saved the nation 1% of its energy costs every day it was in effect. Allegedly, people used the extra daylight to enjoy the outdoors instead of sitting inside and running appliances.

Even though I think that DST is a little bit silly, I'll admit that it does have that effect on my own behavior: suddenly, it's warm enough and light enough that I can take walks and bike rides until seven in the evening. But I wonder if it has the same effect on our national energy consumption as it did thirty years ago. By all accounts, our work schedules are less uniform and more flexible, we spend a lot more time in front of television and computer screens, and we're a lot less likely to spend our leisure time outdoors.

A more recent paper from the California Energy Commission (which has a comprehensive web page about the history and theory of daylight savings) concluded that "there is no clear evidence that electricity will be saved from the earlier start to daylight saving time on March 11, 2007, but the 7 p.m. peak load will probably drop on the order of 3 percent for the remainder of March, lowering capacity requirements." The evening "peak load" is when home dishwashers, laundry machines, and other energy-suckers require the additional use of highly-polluting, short-term power generators. If the early DST reduces the need for those, even if there's no overall energy savings, there would at least be some benefits to air quality. For those enjoying the daylit evening outside instead of on the sofa, that counts as one more thing to like about daylight savings.

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