Measuring Your Appliances' Energy Use

The NY Times had an article today about the huge amount of energy used by cable boxes and digital video recorders (DVRs).  American set-top boxes use more energy than the entire state of Maryland!  Yikes!  As the article points out, it doesn't have to be this way, set-top boxes in Europe use far less power.  The problem is, of course, that energy in the States is far cheaper than in Europe and the $3-5 dollars addition to the monthly electricity bill is probably not even noticed.  And companies aren't going to go out of their way to fix something that isn't noticed by their customers.  I imagine that many customers would demand more efficient electronics if they were aware of the costs.

In order to understand the costs, you have to know how much power each appliance uses.  Fortunately, there are lots of cheap devices that measure just that.  You just plug the appliance into the meter, and then plug the meter into the outlet.  I've been using the Kill A Watt in my apartment and found a few surprises.  For example, my desk speakers (and sub-woofer) which I use maybe once a month, use 10 Watts even when the speakers are completely powered off!  Because of this, I now only plug in the speakers when I want to use them.

The Kill A Watt can measure the instantaneous power used, so you can immediately see how different settings affect an appliance's efficiency (does that "Energy Saver" mode on my AC wall unit actually save energy?)  Also, you can monitor how much total energy is used since you plugged in the appliance.  Your refrigerator may not be running when you first plug it in, but you can use this mode to see how much total energy it uses over an entire day.

So go pick up a power meter!  It's less than $20 and could pay for itself very quickly.