Daylight Saving Time: What's it Saving?

Does “traveling” through time save energy? Is that lost hour of spring sleep really worth it? Where are the savings in Daylight Saving Time and would the Western world be better off dropping the whole thing and moving on with its life?

A (Very) Brief History of DST

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In 1784, after noticing how many residents slept through sunny summer mornings, Benjamin Franklin published an anonymous, satirical letter to Parisians suggesting they get up two hours earlier to conserve candles. Franklin did not suggest they adopt Daylight Saving Time (DST), although often mistakenly credited as doing so, but he did foreshadow a primary controversy that has followed DST around since its 1895 conception by New Zealand entomologist George Vernon Hudson (who enjoyed the extra daylight to scour for insects) - does DST actually save energy?

Even after Hudson and then Brit William Willet fought for DST, it took until World War I for Europe and the United States to temporarily adopt the shift. Then it went in and out of favor - slowly gaining widespread usage in Europe and North America (most of Asia and Africa still do not observe it) - throughout the 20th Century, usually finding its way onto legislative arenas during wartime or energy crises.

george vernon hudsonExcept for a handful of adjustments, DST as we know it in America has been around since the 1960s, when Congress passed the Uniform Time Act, which did not force all states to adopt DST, but merely said that if adopted it must be done uniformly. At that time, it was thought DST would save energy on incandescent lighting, then the primary use of electricity, although now things are more complicated due to widespread heating and cooling.

How DST Works

Daylight Saving Time makes summer days longer, as well as a portion of spring and fall days. As it stands right now, Standard Time “springs forward” at 2:00am on the second Sunday of March, creating darker mornings and brighter evenings until, on the first Sunday in November, it “falls back” into Standard Time. The idea is that people will be happier and more active thanks to more after-work daylight hours to spend outdoors. It’s also believed to conserve energy because the sun is out later and homes are naturally warmer and well-lit until closer to the average person’s bedtime. Obviously, darker, potentially colder mornings would increase the need for light and heat before work, but the belief is that lower energy usage at night outweighs increased usage in the morning. Thus, energy and money is saved.

Well, the thing about that is…who the hell knows? No one can seem to agree whether DST saves or costs both energy and money, or whether it is simply obsolete.

Most of the world’s population does not adhere to DST. According to the California Energy Commission, some 70 countries worldwide embrace it and, while that may seem like a lot, note that most of Africa and Asia do not. So DST is definitely in the minority in terms of global population. In the United States, most of Arizona and all of Hawaii do not oblige the time change. Much of Indiana did not until the latest DST adjustment by the Bush administration, but more on that in a moment.

The recreation, retail, sports and tourism industries have historically supported DST because more time for consumers to be out and about means more money for these sectors. Farmers and the entertainment industry tend to oppose it because a farmer’s schedule is dependent on sunlight, and longer days cut into prime-time revenues for entertainment outlets. But none of that is here or there in terms of energy.

The Energy Crisis

Since the 60s, many studies have been conducted to determine if DST actually saves energy. These studies are in a perpetual state of conflict. For example, during the energy crisis of the 1970s, a study by the U.S. Department of Transportation, which holds jurisdiction over DST, found in 1975 that longer evening daylight hours might reduce electricity consumption in the country by one percent in March and April. energy light offYet a review of that study in 1976 by the National Bureau of Standards found no significant savings.

That trend repeats throughout recent history, all the way up to our most recent decade. In yet another effort to conserve energy, the Energy Policy Act of 2005 signed into law by George W. Bush included another extension of DST. It moved the time change to three weeks earlier in the spring and one week later in the fall. The change went into effect in March of 2007.

It was then that the entire state of Indiana decided to adopt DST. Because several counties had already been observing DST, it gave Matthew Kotchen and Laura Grant of the University of Santa Barbara a unique opportunity to study firsthand the effects of DST on energy consumption. Their study, released in 2008, found that electricity usage actually increased in Indiana following the switch, a fact primarily contributed to an increased need for air conditioning on hot summer days and an increase in heating on darker mornings in the spring and fall.

At that point, it seemed like the jury might be in on DST—that contrary to popular belief, it actually hurt energy efficiency and cost homeowners and the state more money than sticking to standard time year-round. But of course, the Indiana case study is not without criticism, which boils down to the assertion that Indiana cannot represent the entirety of the USA. A handful of studies in California have found either that DST saves a small amount of energy or has little or no effect on energy at all, but certainly doesn’t cost the state energy.

And that tends to be how the debate over DST goes. The US has so many different climates that the effect of changing time to suit schedules in summer time (what DST is called in Europe) varies. Up to this point, no comprehensive nationwide study is complete, although apparently the federal government is in the process of doing just that.

So is DST Worth it or Not?

My extremely strong opinion on the matter? It depends. The fact is that percentage-wise, there seems to be little effect, although a difference of one percent in any state, especially energy-hungry California, can equal a heck of a lot of saved GHG emissions and cost savings. Of course, nobody can say for sure if any energy is actually saved.

Here’s the conundrum. Yes, in a state like Indiana, DST might actually cost energy, but in another state or region it might have a significant impact. The problem is that we live in an interconnected world, so it does nobody any good to have everybody running on a different clock. Time zones alone present enough problems in that respect.

So energy-wise, I opine that DST is essentially pointless, an opinion I’ll stick to until I see the results of a broader study (which will no doubt have to be inordinately complex and probably befuddling to most of us). Most of the world’s population does not observe it in any way and we live in an ever more globalized society.

Now there are other effects of DST beyond energy—traffic accidents, crime, health, economy, et al.—each as contentious as the rest. Wikipedia has a good survey of information on those factors, their own respective controversies and plenty of links to other resources if you’re interested.

But for now, the only reason I can see to hold on to the DST model is convenience and luxury. Even in standard time, few of us actually rise with the sun in summertime. Most peoples’ routines have been structured around the nine-to-five workday, so even if the sun rose at 5 a.m., the majority would probably sleep until it’s time to get ready for work. So, just as Benjamin Franklin, George Vernon Hudson and William Willet suggested at least a century ago, having that extra hour of daylight to frolic, relax, take a walk or just get outside under the bright summer sun…well…who, if it’s not costing us valuable energy, is going to complain about that? Not me.

And hey, maybe someday over the rainbow, solar power and renewable energy will provide the majority of our electricity and all this will be a moot point. Unless you’re a farmer or a major media outlet.


Wikipedia: Daylight Saving Time

Wikipedia: Time in the United States

California Energy Commission

Wall Street Journal

Posted on March 17 in Solar Politics by .

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