Daylight Saving Time (DST)

As many of you know, this early Sunday morning at 2AM, we are going to observe the Daylight Saving Time. This will be probably one of the earliest times in history to observe DST. So my mind began to think – what are the motivations for changing the DST? It just left me clueless until one of our members who works for an energy company forwarded an e-mail to me.

Here is the real reason for the DST change (drum roll please)….

One of the biggest reasons we change our clocks to Daylight Saving Time (DST) is that it saves energy. Energy use and the demand for electricity for lighting our homes is directly connected to when we go to bed and when we get up. Bedtime for most of us is late evening through the year. When we go to bed, we turn off the lights and TV.

In the average home, 25 percent of all the electricity we use is for lighting and small appliances, such as TVs, VCRs and stereos. A good percentage of energy consumed by lighting and appliances occurs in the evening when families are home. By moving the clock ahead one hour, we can cut the amount of electricity we consume each day.

Studies done in the 1970s by the U.S. Department of Transportation show that we trim the entire
country’s electricity usage by about one percent EACH DAY with Daylight Saving Time.

Daylight Saving Time ‘makes’ the sun ‘set’ one hour later and therefore reduces the period between sunset and bedtime by one hour. This means that less electricity would be used for lighting and appliances late in the day.

We also use less electricity because we are home fewer hours during the ‘longer’ days of spring and summer. Most people plan outdoor activities in the extra daylight hours. When we are not at home, we don’t turn on the appliances and lights. A poll done by the U.S. Department of Transportation indicated that Americans liked Daylight Saving Time because ‘there is more light in the evenings – you can do more in the evenings.’ While the amounts of energy saved per household are small… added up they can be very large.

In the winter, the afternoon Daylight Saving Time advantage is offset by the morning’s need for
more lighting. In spring and fall, the advantage is less than one hour. So, Daylight Saving Time saves energy for lighting in all seasons of the year except for the four darkest months of the year (November, December, January and February) when the afternoon advantage is offset by the need for lighting because of late sunrise.

A report was released in May 2001 by the California Energy Commission to see if creating an early DST or going to a year-round DST will help with the electricity problems the state faced in 2000-2002. The study concluded that both Winter Daylight Saving Time and Summer-season Double Daylight SavingTime (DDST) would probably save marginal amounts of electricity – around 3,400 megawatt-hours (MWh) a day in winter (one-half of one percent of winter electricity use – 0.5%) and around 1,500 MWh a day during the summer season (one-fifth of one percent of summer-season use – 0.20%). Winter DST would cut winter peak electricity use by around 1,100 megawatts on average, or 3.4 percent. Summer Double DST would cause a smaller (220 MW) and more uncertain drop in the peak, but it could still save hundreds of millions of dollars because it would shift electricity use to low demand (cheaper) morning hours and decrease electricity use during higher demand hours.

The model used in the Energy Commission’s study is now being used by the U.S. Department of Energy in a larger national study of daylight saving time. It’s unknown when that study will be completed. In May 2001, the California state legislature sent a Senate Joint Resolution (SJRX2 1) to the White House and Congress asking that states be allowed to extend Daylight Saving Time year round. Congress and the White House did not act on the request because of the world-changing events of September 11, 2001. No new legislation has been passed in California since then.

Blah, blah, blah… so the bottom line is we save energy and we have more daylight… yahoo!