Keeping Tabs on Your Energy Hogs
Greentips: February 2010
Using monthly electric bills to keep track of your energy use can prove frustrating since appliances consume different amounts of energy at different times and the bill comes weeks after the electricity is consumed. However, a growing number of devices allow homeowners to track their electricity use in real time. According to an Oxford University study (see the Related Resources), this type of direct feedback on energy use typically helps homeowners reduce their energy consumption—and costs—by 5 to 15 percent.
Whole-house meters. This type of device connects either to your home’s circuit breaker box or electric utility meter, and wirelessly transmits data to a portable digital console. The console displays both your current electricity usage and the related cost based on your utility rate (which you program into the console). This information allows you to measure how your consumption changes throughout the day, such as when your refrigerator’s compressor turns on or when you turn your television off.
Whole-house meters vary in price from approximately $100 to $200 depending on their features. Some can measure consumption at two different rates (if your utility’s rate changes based on time of day or total usage), while others can factor in the effect of home energy systems such as rooftop solar panels that offset conventional electricity use.
Plug-in meters. These devices are a less expensive but somewhat more limited option for tracking the energy consumption of individual appliances. You simply plug the meter into an outlet and plug an appliance into the meter, which displays the appliance’s electricity usage as it operates.
For as little as $30, these gadgets allow you to measure how much electricity an appliance uses in various power settings, including standby mode (when the appliance continues to draw power even though it is turned off). You can also measure consumption over time, which can be helpful for appliances such as refrigerators that draw varying amounts of electricity during the day. One drawback of plug-in meters is that they cannot measure the contribution of “hard-wired” appliances such as central air conditioners, water heaters, or wall/ceiling light fixtures, which can represent up to 40 percent of home electricity usage. (See the Related Resources for a list of appliance consumption figures.)
