The Kill A Watt device caught my attention, simply because it provides information about the power consumption of your devices, and can be found for under $50, making it somewhat affordable. I was interested in seeing how much power our household electronics and appliances were using – in particular the computers, as well as the TV that usually gets left on all night.

After coming across one of these on eBay, I decided to give it a try. It claims to be accurate within 0.2%, and says that “the knowledge you gain from Kill A Watt will save you thousands of dollars.” While I somehow doubt a device in that price range has a margin of error of less than 0.2% in all it’s measurements, I’d imagine it’s close. I doubt even more that it will save me thousands of dollars, but of course, that’s marketing for ya…

The Kill A Watt is pretty simple to use. You simply plug it in between your power outlet and the device you’re powering. It has 6 buttons which will let you display either of the following on the LCD:

• Volts
• Amps
• Watts
• VA (Vrms Arms)
• Frequency (Hz)
• Power Factor (W/Vrms Arms)
• KWH since plugged in
• Hours since plugged in

Now before you decide that you’re going to hook a massive power bar on the end of this device and hook up all your household items to it to test your entire household power consumption… this thing does have limits… A max of 125V and 15A. So while this will probably run quite a few things at a time, don’t be trying to hook it up to a 220-240V furnace or anything that’s going to draw massive current. Fortunately, many household circuit breakers are rated for about 15 amps, so you’ll probably throw a breaker before you fry this unit anyway.

After receiving the Kill A Watt, I plugged it in and started testing things. As it turns out, falling asleep to a DVD playing is using about 120W of power at night, between the DVD player, the TV, and the receiver. Not much worse than leaving a 100W lightbulb on I suppose, and a little less than I thought it would be. When turned off, the DVD Player uses 0W, the receiver 1W, the TV 5W, and surprisingly, the VCR uses 4W when off. Throughout the next few days, I’ll undoubtedly be testing it on other devices to see what numbers I come up with.

In short, the device does have merit in that it can help you to lower your power bill. It can help you to determine what the most power-hungry devices are in your home, and even help determine what the power consumption effects are of different actions (for example, turning down the fridge). Aside from that, even if you don’t need to make changes in your home, it remains an interesting device nonetheless.

The Kill A Watt can usually be found on eBay.