Tuesday, August 14, 2007

Reduce--personal energy usage

The student housing that I have been issued as a master's student at the Blaustein Institute for Desert Research is environmentally friendly. It is lit during the day by daylight. It is heated in the winter by passive solar heating and during the summer we keep it cool by keeping everything closed. We have a solar hot water heater. I believe that the materials they used weren't the most sustainable, although I would have to check. This is a shame because according to the New York Times, the most important energy usage in buildings comes from the construction phase, so the building of the materials and then the durability of the house (if it isn't durable, you have to construct it again quickly).

However, living in a house that is designed to reduce my energy consumption has been interesting. I never gave a lot of thought to these issues, or the thought I gave was based on how much I was paying, before.

Nevertheless, my husband and I found that even here, we are among the highest electricity users. How could this be? I care about conservation. But it appears that like many conservationists, I care, but don't let that translate into action. I think it probably boils down to the big conservation indicator--wealth. My husband is older than I, saved money before returning for his Ph.D., and earns a higher scholarship than I. And we pool our resources and don't have children. So we don't have the same economic incentive to conserve electricity and have more devices that use electricity.

Even so, our electricity consumption is made up of the following:
12 lights (one of which I now replaced with a fluorescent)
1 ceiling fan
1 electronic fan
electronic component of our hot water heater
hair dryer (SELDOM used)
hot plate
electric teakettle
cable box
sony playstation
chargers for camera, cell phones, toothbrushes
electronic fan in the bathroom
2 space heaters
alarm clock
That is 32 items. Since hearing that we are high electricity consumers, I have tried to make some changes.

1. when a light went out, I replaced it with fluorescent lightbulb. DH hated the light, and it was in the area he uses as a workspace when he works from home. Instead, I put the fluorescent in the outside light, which we seldom use, but which it is possible to accidentally turn on and leave on, causing a big electricity drain.

2. I learned that vampires, things that suck energy when they are plugged in, even if not on, can use 10% of your electricity. For example a tv or cable box. So I try diligently to unplug them when not on, and educated DH about that. Also chargers stay unplugged now when not in use.

3. I learned that despite my previous hazy notion, items like computers do use more energy when left on. So now I try to always turn off the computer when not in use, and also pay attention to other things like the ceiling fan or radio, and turn them off.

Even with these changes, we have not done anything drastic. Our biggest usage is probably due to the fact that I am one of those people who is always cold, so we were leaving a space heater on overnight in the winter. What we should have done, is bought an extra blanket. Surely we could have even bought a used one, or borrowed one from DH's family. It is embarrassing to write that we didn't do that, but one must be honest.


Working Girl said...


So how much energy do computers use up? Compared to, say, a refrigerator?

I don't leave my computer when I'm not using it, mainly because it seems "safer" to me.

CC said...

Hi Working Girl,
Thanks for your comment. That is a good question, and the US Department of Energy will try to answer it for you here.
This page contains estimates of the energy use of common appliances. So a refrigerator would have a wattage of 725, and a computer would have a wattage of 120, a monitor 150. When the computer and monitor are "asleep" they each have a wattage of 30 or less. When doing calculations of the energy used, the DOE recommends dividing the refrigerators hours by four, since they cycle on and off.

You multiply wattage by hours used per day and divide by 1000 to attain the daily kilowatt hour usage. You can multiply this out by year to figure out the yearly use.

So specifically your settings will determine how much energy is used by your computer and monitor. If you leave it on but sleeping for 16 hours per day while you are not using it, the multiplication would look like this:
(60 x 16 x 365) / 1000 = 350.4
If you factor in 8 hours a day of work use, the multiplication would look like this:
(270 x 8 x 365) / 1000 = 788.4
A refrigerator's multiplication would look like this:
(725 x 6 x 365) / 1000 = 1587.75
Of course if you have an energy star refrigerator the math would be different. If you have a laptop, the math would also be different. The DOE figure for wattage for a laptop is 50--I imagine it is lower if you put it on energy saver mode. And I hope you don't work 365 days per year : )
The DOE's guidelines for when to turn off your computer are here.
And energy saving tips for your refrigerator are here.