One Outlet at a Time

The cheapest, easiest way to calculate your power consumption is with a plug-in electricity monitor, such as the basic $24 Kill A Watt. Electricity monitors are like outlets with digital displays. Plug the monitor into the wall, and plug a device into the monitor. The monitor shows electric consumption in kilowatt-hours, just like your utility bill. You can use the figures to calculate the monthly or annual energy costs for each device or appliance.


The wattage of a lamp with a 100-watt bulb is not a mystery. The Kill A Watt is more useful for computer stations and home entertainment systems. If a TV, DVD player, stereo receiver, digital video recorder and video gaming system are all plugged into a power strip, you can measure the total power load. Moreover, you can unplug each device and determine which devices draw significant amounts if power when they are switched off or on standby.


Newer $60 Kill A Watt models include a surge protector and can be pre-programmed to turn devices on and off as needed.