Monday, March 26, 2007

Moving the Hands of Time

A key point about energy efficiency is how it can be manifested in many ways. A recent example is the early three week change of Daylight Savings time. When the hour is jumped ahead in the spring, our consumption of energy changes. It might sound strange, but the truth lies in your lifestyle.

During the winter months in Canada the sun will set at approximately 5 pm. This is typically when you would leave work, arrive at home after your commute and meet up with the rest of your family. Since the sun has set, the streets are lit up by the yellow glow of the city streetlights. At home, you turn on your front door light, and perhaps the hallway lights too. Someone in the kitchen has those lights on and whoever is in other rooms in the house have lit those spaces. The electricity is flowing strong into your house and as well as all the other houses around you.

This is peak power. Everyone activating the electricity service at the same time puts lots of pressure on the producers of electricity. It is expensive to produce electricity at this time too, because it is usually expensive fuel or an expensive system that needs to run, when all other cheaper sources are busy. In some places the cost during peak power can be as high as 20 cents for every kWh of electricity, while normal hour electricity is around 5-7 cents per kWh.

Now if we change the clock time, like all of you did a few weeks ago and I did it last night, by one hour, a shift in activities occurs. Now in a typical March day the sun will set at 6 pm, instead of the usual 5 pm. What happens at 6 pm in your household? You are probably finishing your meals or cleaning up, settling for an evening with a good book or a fun reality tv show. The usual hustle and bustle that happens at the 5 pm hour is all performed in daylight, which eliminates all those lights.

Peak power is reduced! The cost drops slightly, but still, a smaller peak consumption rate exists. When we add 4 weeks more to our summer hours (3 weeks earlier in spring, one week later in the fall), there is significant change in the size of peak electricity during the whole year.

Another simple example of energy efficiency at work. Imagine if we change all our lights to be low energy consumption bulbs....


Anonymous Anonymous said...


2:48 AM  
Anonymous Anonymous said...

Never though of the day saving light that way.
but before the change I had light in the morning now I go to work in the morning dark again, although is changing little by little.

3:50 AM  

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