How to Save Energy at Home Using a Power Meter

By using a power meter to understand how the appliances in your home are using energy, you can cut your electric bills by as much as 10 to 20 percent and become more energy efficient.  Certain plugged-in appliances, along with charger cords and power strips, continue to consume “vampire power” when they’re not in use and are some of the biggest energy wasters.  This article explains how you can use a power meter to identify the vampire power culprits and high-energy use appliances in your home so you can reduce overall energy costs. Save energy at home using a power meter


What is Vampire Power? 

Vampire power (aka “standby power” or “phantom load”) is a term used to describe the electricity used by appliances like TV sets, cable boxes, cell-phone chargers, computers and other gadgets when they are plugged in but not in use.  It is estimated that the average U.S. household has 20 to 40 devices that suck vampire power.  Although each device consumes only a small amount of electricity when “off,” the U.S. Department of Energy reports that the average U.S. household spends about $100 per year to power devices while they are off or in standby mode.

Thanks to the proliferation of rechargeable gadgets, computer networks and devices with standby power functions, vampire power has been on the rise during the past decade.   Examples include: Charger cords consumer vampire power

  • Charger cords and AC adaptors – A cell phone or computer charging cord plugged into an outlet draws a constant supply of energy, even when the batteries are fully charged or the device is not connected.
  • Appliances with display screens – Coffee makers or microwave ovens with a digital clock use energy continuously to power the clock.
  • Gadgets in standby mode – A printer or computer in “sleep” or standby mode is still consuming energy so it can turn on instantly when you want to use it.  So are TV sets that go on immediately when you press the remote control.


Identify Your Energy Wasting Appliances 

A wall outlet power meter (or energy monitor or watt meter) is an energy usage monitoring device you can use to accurately measure the amount of electricity used by an appliance and identify which ones are using the most power.   A power meter will help you find those devices that are consuming vampire power as well as any older appliances that you may want to replace with more energy-efficient models.Kill A Watt Electricity Usage Monitor

It’s easy to use a wall outlet power meter.  Just plug any 120-volt appliance into it and plug the power meter into a wall socket.  The power meter begins counting wattage usage instantly.  Leave the power meter and appliance connected for as long as you typically use the appliance.  If it’s a window air conditioner, for instance, leave the unit running until the room cools down to your preferred temperature.  If you want to check your old basement freezer, keep it plugged into the power meter for 24 hours.  The power meter will tell you exactly how much electricity the appliance used in that amount of time.


Know the True Cost of Running an Appliance 

Some power meters, like the Kill A Watt EZ Electric Usage and the Kill A Watt Power Monitoring for Dummies, can also figure out the cost of energy used by each appliance you test.  Enter your cost per kilowatt-hour (which you can find on your utility bill) into the meter and the power meter will do the math for you and display that information in dollars and cents.


Use this Data to Save Money 

Once you know how much an appliance contributes to your energy costs, you can use that knowledge to save money.

Some easy energy-reducing steps include:

      • Using the appliance less;
      • Using the appliance at lower-cost times of day (ask your utility provider when those are);
      • Unplugging charger cords when not in use;
      • Using a power strip as a central “turn off” point to completely disconnect the power supply to several pieces of equipment at one time;
      • Using a “Smart” power strip that works on either timers, occupancy sensing or current sensing to automatically reduce  the vampire power consumed by devices and appliances when they are not is use;
      • Replacing old appliances with newer Energy Star rated models.


And here’s one last important tip:  Bring your power meter with you when you go shopping for new appliances so you can compare the energy usage and costs of different brands and models right there in the store.

2 thoughts on “How to Save Energy at Home Using a Power Meter

  1. Wow, great article! Vampire power suckers are something that you dont think of all the time. Would something like a power cord help to alleviate some of the energy usage? Because if it has a switch to bring power to the TV, cell phone charger, and other vampire appliances would that work?

    1. Eric, there is something called a “smart” power strip that works on either a timer, occupancy sensing or current sensing to automatically reduce the vampire power consumed by devices and appliances when they are not is use. There are even “smart” power strip charging stations designed to prevent idle power loss while you are recharging multiple devices! You can read more about “smart” power strips at the Energy Savers, Surge Protectors page on the store site.

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