Article, December 2008
by Jerry Grommes,
Past President, Sandwich Computer Users Group, Illinois
Obtained from APCUG with the author's permission for publication by APCUG member groups.
During our June program, there was quite a discussion about whether to leave your computer on verses shutting it off when not in use.
I, personally, like to leave my computers run so they are kept up-to-date with auto updates and backed up with scheduled backups. These tasks are done in the early AM so my computers are fully functional when I sit down to use them.
However, others asked why not just leave them on the nights that the backup runs instead of 24/7. I didn’t think it was using much energy by running 24/7 but decided to check it out and run some tests using my “Kill-AWatt” meter. (Measures watts, amps, hours, kill a watt hours, ect.) I started with my newest computer (which is approx 2 years old and probably the most efficient). This machine is running Vista and I had the Power Options set to turn off the monitor after “20 minutes” and put computer to sleep to “never”. With these settings the computer was drawing between 110 and 140 Watts of power with a total average of 2.63 KWH (kill-a-watt hours) per day. Cost per day was $.026 ($7.87 a month) based on my most recent bill.
I then changed the Power Options to turn off the monitor after “20 minutes” and put computer to sleep “after 2 hours”.
The watts dropped from between 110 and 140 while I was using the computer to 6 while in the sleep mode and the total average of KWH dropped to 0.65 per day. Cost is now down to 6 cents a day ($1.94 a month).
With the current power options (turn off the monitor after “20 minutes” and sleep “after 2 hours”) the computer will wake up and get updates as well as run the scheduled backups. So with a simple change to a power option, I was able to reduce power consumption by approx 76% and save $5.93 per month with out affecting my user experience.
I plan on testing my XP machine next to see what it is costing and to see if it can be reduced. Thanks go to Louise and the rest of the group for a great discussion on energy use.
To get more info and tips on energy savings try one of Louise Dieden’s favorite links: http://www.energy.gov/forconsumers.htm Louise is a SCUG Board Member at Large.
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