Recently, Barbara picked up a new clock for my nightstand. It wasn't new-from-the-store, but it was new to me, and looks the same as any new-from-the-store clock would look one month after you took it out of its package. The clock it replaced was purchased used and then donated to a charity.
So, the new clock has a much higher utility, but even better still, its power draw is two watts less than the clock before. What is two watts to me, you ask? It is only 0.048 Kwh/day, which is still only half a cent a day at baseline usage rates. However, that 0.048 Kwh/day runs up to 17 Kwh per year, and if you're using a lot of electricity, the "300% over baseline"[1] rate is currently $0.47/Kwh, which means that the marginal cost of those 2 watts is up to $8.23 per year.
Now you're not likely to break the piggy-bank on a few dollars of electricity per year, but it is an interesting thought process to realize that even a small energy draw will add up to something significant over the course of the year when the item is on all the time. When you multiply that by the number of small appliances in households around the world, it becomes apparant that for continuous-use devices, any small savings in consumption is worth pursuing. Most people are aware of the fact that many electronic devices draw standby power as long as they remain plugged in. Did you know that standby power for a typical device can run between ten and fifteen watts[2]? That's $10 - $40 per year per device that you leave plugged in when you're not using it!
It really makes sense to think about the energy consumption of the devices that stay on all the time, but it's also important to remember that it also costs energy and resources to make stuff[3], so you're not necessarily saving anything if you throw something that still works into a landfill in order to buy something new that uses less electricity. We don't pay all of the costs associated with the things we buy, so it is important to make good decisions when the time comes to make a needed purchase.
One area where our familiy is above-average in energy use is computers. Our total electrical consumption runs from ten to fourteen Kwh per day, and while we haven't measured individual devices yet, a lot of this comes from our computer use. Recently, the motherboard died on my computer, after happily chugging along for over four years. It was tempting to just run out and buy replacement parts to put in the same case, but I knew we could do better.
We came up with the following improvements.
Downsize the full-time computer. We run services from our house, so we keep a computer on all the time. The system that died was a full-sized tower with a 450 watt power supply. Rather than rebuild it, I moved all of our services to our son's computer, which is a small Shuttle that runs on a 250 watt supply. Overall, the power savings will probably be over 2 Kwh per day.
Switch to a laptop for my primary computer. Laptops use much less energy than desktops. I happened to have an old laptop with a semi-busted screen. If you touch it wrong, the bottom one-third of the screen garbles, so it is no longer very useful as a laptop. It is working just fine as a mini-desktop, though.
Sleep computers that are not in use. My computer was on all the time because it had to be, and Barbara's was on all the time too because she used it periodically throughout the day. Our son also got into the habit of leaving his computer on all the time too. Barbara was already in the habit of turning off the monitor, and now she is also putting her computer to sleep when she's not using it, which saves quite a bit of power. Since I'm on a laptop now, I also put my computer to sleep when it's not in use. I estimate we'll save another 1~2 Kwh per day from this behavior change.
Use "green" components. When I moved to the Shuttle system I needed a new hard drive. Byron "only" had 120Gb on his system, and between all of the backups and assorted junk I had on my main system, I didn't think that was going to cut it for the gateway. I was running dual drives totalling 600Gb, but I only wanted to put a single drive in the Shuttle to keep heat and power draw to a minimum. I have to admit that this is the one part of the whole reconfiguration that I was most uncertain about. Probably the greenest thing to do would have been to get my "virtual junk" cleaned up and learn to live in 300Gb, but I tend to use my systems for a long period of time, and I'm getting used to having 1TB drives. Fortunately, the Western Digital 1TB "Caviar Green" [4] drive made the purchace decision easier to live with. It draws just 5 watts of power, compared to around 20 watts for a typical drive, and Amazon had it for just $85 with free shipping.
Re-use what you can! It's always a little sad when a computer dies, but there's really no need to chuck the whole thing in the wastebin when it does. My dead computer became an "organ donar" for the other systems that were still alive and kicking. The 4GB of RAM went into my son's computer. The 1GB he already had became a RAM upgrade for Barbara's computer. The network card and SD card reader also migrated from the dead system to Byron's computer, and I still have a nice case and three hard drives that I can sell on Craigslist.
After all of these changes, we're looking forward to seeing our January and February electric bills. We're hoping that over the course of the next year that we might see our 10 - 14 Kw/day drop to 6 - 10 Kw/day or so. Of course, all of our calculations are based on estimates; time will tell how well we really did.
Footnotes:
1: PG&E Electric rates: http://www.pge.com/tariffs/ERS.SHTML#ERS
2: Standby Power: http://en.wikipedia.org/wiki/Standby_power
3: The Story of Stuff: http://www.storyofstuff.com/
4: Caviar Green hard drive: http://www.amazon.com/Western-Digital-Intellipower-WD10EADS-Frustration-Free/dp/B001IEZX3G
- Log in to post comments