We Get Greener Kit Cassingham & her Bigger Half

Greener Computing

And is there a way to make a greener decision? Yes.

I used to have a desktop computer. I loved it for its power and speed. And the purchase price was good too. It became inadequate for my needs when I started traveling more.

How can I travel with my desktop computer? For a few years I opted to keep a notebook computer available for traveling. Before each trip I transferred the files I'd need from the desktop to the laptop. Oh, did that get old!

When we moved from Boulder, Colorado, to Ridgway, Colorado, where we lived in a yurt for nine months while our house was being built, I realized one way I could economize on space was to just use my notebook computer and not bother with the desktop. When you live and work in 300 "round feet", every cubic inch matters.

When it was time to get a new laptop, I got one that was capable enough to handle everything I needed to do, and used it all the time -- I could get rid of my desktop machine altogether, and have one computer, instead of two. That's very obviously more environmental. Traveling was less frustrating because I didn't have to do the file transfer anymore. Working was just as convenient with the laptop as the desktop.

The unanticipated bonus was the energy savings. Running a desktop computer and the monitor consumes more energy than a laptop computer does. In the summer we enjoyed the reduced heat load too. Of course, there were some winter nights where every little bit of extra heat would have been appreciated. But in general, what a wonderful green action to have taken!

How much electricity does your computer use? If you want to know exactly how much your computer uses you can get a watt meter and measure a typical 24 hour period. Multiplying that by the number of days a year the computer is on, even asleep, and dividing that product by 1,000, will tell you how many kilowatt hours (kWh) your computer setup uses.

Or multiply the watt rating your computer has (the number can be found on the back of your computer) by the number of hours a day it's on, and divide that product by 1,000 to get your daily kWh consumption. Multiply that by the number of days per year your computer is on to get your annual kWh consumption.

If you just want to generally know about computer consumption here's a list.
- typical desktop computer: 60-250w
- typical CRT: 85w
- typical LCD: 35w
- laptop: 15-45w
And newer computers, especially those that are Energy Star rated, consume less electricity than older computers.

According to one source, computers are the second highest energy consumer in the office, after lighting, consuming 40-60 percent of the office electricity used. You can save an enormous amount of electricity if you turn your computer off at night and on the weekends; those parts of the week account for 75 percent of the week. Further savings can be enjoyed by putting your computer into idle or "sleep" mode, a low power mode, when you aren't using it during the day.

Having a laptop computer is one energy saving step I take, but hibernating it at night and turning the extra monitor off too, is another step I take. It feels good to take easy, little steps like that.

If you want to be really energy conserving you could have your computer plugged into a power strip that you turn off at the end of the day and week; that cuts the phantom load that draws electricity even when an appliance isn't "running". I take that step when I'm traveling (my computer always goes with me) to cut the phantom load of my monitor and other peripherals.

When it's time to buy my next computer I'll be more attentive to its energy efficiency, and then manage the daily load closely.


I've often wondered just how many watts am I burning with a particular item. A couple years ago, someone suggested a product called Kill-A-Watt by P3, supposedly for about $20. Hardware stores & such have them for near $40, but I got mine from Amazon for $26, a model P4400. It has a nice digital readout that gives me watts, amps, volts, power factor for ac watts, etc. Now I know exactly what I'm burning for any 120v device, rather than having to hunt for a tag that states "typical" power consumption. Cyclic devices, such as refrigerators that turn on and off require a little more work to calculate, and it's no good for 220v appliances, but it's cheap and adequately reliable for nearly all devices in my home.

I'm certain that you are familar with it, but I mention it for other readers who might want to see just how much electricity is going to waste. Depending on the electric utility, a person could be spending between 7¢ - 10¢ for each one of those watts if left on 24/7 over a month's time. For a 150 watt computer, that could mean an extra $15 ($180/yr)spent on that machine alone.

Mike from Dallas at July 2, 2010 2:10 PM


Thanks for posting about that. Yes, I do know about Kill-A-Watt. In fact, we have one! :~)

It's fascinating to see how much energy our various appliances consume. We've tested our electric toothbrush, bread machine, computers, and battery chargers, for starters.

That's helped me unplug things I'm not using as one way of saving energy. It's a small thing to do, but little things add up to big things.


Kit Cassingham at July 2, 2010 2:46 PM


I agree with you entirely about the energy saving properties of a laptop over a desktop computer. I recently sold my desktop and bought a lappie as my primary computer. Given the large screens and excellent computing power of current laptops, there's no reason not to for most applications.

I have a 12 VDC power system in my house for running the ham radio gear in case of a power failure and I also run my laptops on that system as well. That ensures that I still have the radar feed if the power goes out.

For those who'd like to run their laptops on 12 VDC power, Lind Electronics provides 12 VDC power adapters for most any laptop made. Their latest product is a 12 VDC/120 VAC power supply with a USB charge output to keep your cell phone or other USB chargeable device up to par. And it does its job on either 120 VAC or 12 VDC. The one I ordered for my new Toshiba A665D just came in today.


Larry D Barr at August 11, 2010 9:42 PM

I'm glad to see you have your priorities straight -- keep the radio on the air! I keep mine on the "solar outlets" too. ;~) I have a friend who has a 12 volt back up system too -- though I think he keeps some lights and his radio on it.

-Kit (K0KIT)

Kit Cassingham at August 12, 2010 2:57 PM
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