« Seattle's Growing Up | Main | Does Pollution Vanish in Sunshine? »

March 23, 2006

Giant Power Sucking Sound

Here's one problem that should be relatively easy to fix:  appliances that use power even when they're not in use.  The Economist has a nice summary of the problem:

Strange though it seems, a typical microwave oven consumes more electricity powering its digital clock than it does heating food. For while heating food requires more than 100 times as much power as running the clock, most microwave ovens stand idle—in “standby” mode—more than 99% of the time.

Apparently, somewhere between 5 and 13 percent of residential power is consumed by appliances that nobody is actually using.  Hmph.

Now, the most interesting thing here is that different brands and models of the same kinds of appliance use wildly different amounts of power in standby mode.  One compact disc player may draw 1 watt while idling; another might draw 30.  Manufacturers have little incentive to improve the situation on their own, since they don't pay the power bills; and while energy wonks are well aware of the problem, few consumers pay much attention.

The solution here -- dare I even say it -- seems to be government intervention.  In 2004, California passed a law that imposed limits on standby power consumption. It took effect in January, so that (according to the Economist) "it is now illegal in California to sell a television or DVD player that consumes more than three watts in standby mode." Seems like a pretty reasonable solution to me -- I'll be very interested to see if it works.

(Hat tip to Maarten.)

Posted by ClarkWD | Permalink


TrackBack URL for this entry:

Listed below are links to weblogs that reference Giant Power Sucking Sound:


I recently purchased a Toshiba DLP projection TV. Being the energy nut that I am the first thing I did when I got it home was to check how much energy it used in standby mode. I measured a constant draw of 36 watts, which translates into approximately 315 kWh. That is almost as much energy as an efficient refrigerator uses over a year.

I returned the TV, for other reasons I won’t go into, and ended up purchasing a Sony LCD TV. The Sony is Energy Star certified and draws less than 3 watts in standby mode which translates to approximately 21 kWh annually – a huge difference.

One other item that uses a ton of power is our Comcast DVR: 44.4 watts in standby mode or 388 kWh on an annual basis. I doubt Comcast would ever advertise that their cable box costs you an extra $2.33 per month for electricity when they are selling you all of the cable packages – maybe they should. (Yes, I know I could save this energy by killing my TV. Nobody’s perfect)

Posted by: Matt Leber | Mar 24, 2006 12:21:11 PM

Here's a correction: It was a Samsung DLP rear projection TV and it used 39.6 watts or 346.9 kWh per year in standby mode. Anyway, you get the idea.

Posted by: Matt Leber | Mar 24, 2006 12:27:59 PM

As part of some courses I run, we cover standby loads and it surprising how many there are in a typical house. As rule of thumb we use an arbitrary (and low) figure of 5W per device and then list on a a whiteboard what devices people have in their houses. Multiplying the number by 5 gives people an idea of how much power and money they are wasting. It's easy to get in excess of 15 devices which tranlates to 75W. That's the same as leaving a 75W light globe on 24 hours per day, 365 days per year.

But how do you tell which devices are consuming stanby power. The best way is to measure it. Some manuals state their standby consumption. However, the good way is to identify all those appliances that have:

1. A Remote control (eg TV, stereo, DVD, etc)
2. A Clock (eg microwave, CD player, oven)
3. Soft-touch buttons (eg washing machine, PC)
4. A light on (eg printer)
5. An external supply/plugpack/Wallwart (eg phone charger, electric toothbrush, shaver, games console)
6. A humming noise (eg many computer speakers have an internal plugpack)
7. wasted heat and are warm when not in use(eg breadmaker)

It's quite a list.

The simplest way to reduce power is to switch off at the outlet or unplug the device. Obviously this isn't always practical or convenient (unless there is a 14 year old boy in the house you'll never be able to reprogram the VCR or DVD recorder) but you can make a big difference just by turning off a few things like the computer and all the peripherals, the various plugpacks, perhaps the washing machine and the microwave. It is worthwhile to invest in a powerboard for the computer equipment and the stereo/home entertainment system so that everything can be switched off at the flick of a switch.

Count up all the things in your house and see how you compare.


Posted by: Mike | Mar 27, 2006 4:01:17 AM

There is an interesting gadget called the Kill-A-Watt (made by P3, available from Amazon or fine green-geek outfitters nationwide) which you can plug into your wall, plug a device through, and it gives a readout of the power consumption of whatever you have plugged in. I have one and haven't profiled my whole house yet but I can confidently say it's massively cool.

Posted by: Patrick Niemeyer | Mar 27, 2006 2:56:06 PM

Off-gridders have long been aware of this phenomenon, and part of the checklist for cost of going off-grid is the replacement cost for some of these appliances or the repair cost to disconnect standby mode (in the excellent list that Mike lays out). Alternatively, you can unplug TV, microwave, PC, coffee maker, stereo.

Posted by: Dano | Mar 27, 2006 6:29:17 PM