Who wants to pay more on their electric bill if they don’t have to? Here’s how to identify and measure phantom loads to save money.
What is a phantom load?
“Phantom load” is a phrase commonly used to refer to the standby power consumed by appliances and devices when they are not in active use.
If you’re listening to music through your home stereo setup and the draw is 80 watts, that’s the active load. When the stereo is off and still drawing 5 watts of power, that’s phantom load.
However, not all phantom loads are inherently bad, even if your initial reaction is to assume that any power used when you’re not actively using a device or appliance is wasted power. There are pros and cons to phantom charging a device, with almost all of the pros focused on our convenience, like ensuring devices power up quickly or retain their settings.
But eliminating phantom loads around your home when those phantom loads don’t benefit you or make your life more comfortable is a noble endeavor that’s good for the environment and will save you money.
How much money do you want to save? While that largely depends on the makeup of your home and how many devices you have, the average home could easily save hundreds of dollars a year in electricity costs by aggressively eliminating phantom loads.
But do not worry; we won’t leave you hanging with a vague estimate. In a moment, we’ll show you how to measure loads yourself and calculate how much they cost you.
How to identify phantom loads
So how do you identify which devices have a phantom charge and which don’t? While the only way to be sure is to actually measure the power consumption of the device, there are some telltale signs.
Here are some basic questions you can ask about a given device. If the answer to any question is yes, the device has a phantom power load.
- Is the device or device “wall wart” charging block hot to the touch when the device is turned off?
- Does it have remote control or can it be turned on remotely via local network or other means?
- Do you have any lights, displays, or other indicators that stay on when the device is off?
- Is the device programmable and/or does it retain settings, without the aid of a battery, between uses?
- Does the appliance have a timer function to automate any process (make coffee, turn on lamps, etc.)?
In short, if a device turns on instantly (especially by remote control) or appears to be ready to go as if it was partially turned on and waiting, that’s a good indicator that it was, in fact, partially turned on.
How to measure phantom loads
Let’s look at how to measure a phantom load on an individual device level and then, for the curious, how to check the phantom power of your entire home.
How to measure the phantom load of individual devices
While putting your hand on a power brick and feeling the heat will tell you that the device is using some power, it won’t tell you how much. To find out how much, you need a measuring device.
Our device of choice, and one we’ve recommended for years, is the P3 International P4460 Kill a Watt Electricity Monitor. Not only can you plug in a device and see exactly how many watts of power the device consumes, but you can also schedule Kill a Watt with your local electricity price per kWh and get an on-device estimate of how much a given device costs you to run per day. , week, month and year.
Kill a Watt is accurate to 0.2% of power and can measure down to 0.1W. Although it is worth noting that below 1W, especially below 0.5W, basic commercial wattmeters, including the Kill a Watt Watt, are less accurate.
At extremely low standby power levels, you need more sophisticated laboratory equipment to measure power with extreme precision. For our purposes, however, Kill a Watt is useful and of great value. It is more important to find out if a device has a 20W phantom load than it is to find out if the phantom load is actually 0.6W or 0.4W.
We have a detailed guide to using the Kill A Watt meter to measure your home’s energy use if you’d like to read more about it, but using it to measure the standby power of a single device is pretty straightforward. Just plug it in and read the output to the screen.
You may be surprised by the results, by the way. While many devices, like a cell phone charger, will have a phantom charge so small that Kill a Watt won’t be able to measure it, other things use more power than you might expect.
I tested several Samsung smart TVs in my home, for example, and idle phantom charging ranged from 14 to 18W, depending on the size of the TV. With an energy cost of 12 cents per kWh, leaving TVs plugged in and sitting idle for a year costs about $17 per TV.
How to measure the net phantom load of your home
Measuring individual device loads to determine if, on a case-by-case basis, keeping devices plugged in all the time is one thing. But what if you’re curious about the overall phantom load in your home?
That’s something new to be curious about. Your home has a “standby” mode when you’re not enjoying all the comforts, so what is it? This is how you can get a rough idea of how much energy your home consumes in different states.
To do this, you will need access to your home energy meter in order to read the data presented on it. You will also need a stopwatch and a calculator. We describe the required method and equation in the “Using Your Electric Meter to Measure Electric Usage” section of this article, so please review that section before proceeding, as we won’t be repeating the entire process here. Instead, we’ll focus on tips to help you get a real sense of what the net phantom load of your home is.
First, let’s establish a baseline to have a point of reference and a base to judge any changes. Don’t change anything in your home, like unplugging devices. Go out to the meter and measure the energy use with the technique described in the previous article. Let’s say, as an example, that you estimate your hourly power consumption to be 1400 W, which is pretty close to the national average.
After establishing the baseline, go into your home and turn off or unplug any appliance or device that is necessary for the operation of your home and/or cannot be unplugged.
For example, you would never turn off your oven to save backup power, or unplug your refrigerator. Efficient or not, those things need to stay on for your safety and well-being. However, by briefly turning them off, we can remove any backup power they may consume from our home evaluation and focus on everything else that remains plugged in, like TVs, computers, smart speakers, etc.
With those items unplugged and the remaining devices in the home plugged in but turned off, go back outside and check your meter again. As an example, let’s say the reading and your calculations indicate that your home is using 900W of power. That’s the collective idle power consumption of everything (except the fridge and whatever you just unplugged) in your home. Every television, every power strip, every phone charger, even the smallest phantom charge, if present, from every circuit board in every LED light bulb.
If you’re even more curious, you can go back and unplug more stuff. Unplug the TV in the guest room. Unplug your old game console that you hardly ever play. Unplug anything you don’t want to have instant, seamless access to. If you’re willing to be disturbed a little every now and then to plug it in and save money, unplug it now.
Take a final reading of the power meter. Let’s say the reading is now 600W. The difference between the idle but plugged in reading, 900 W, and the idle but unplugged reading, 600 W, is 300 W.
At 12 cents per kWh, a standby charge of 300W, over the course of a full year, costs you $315.36. That’s not exactly an insignificant amount of money, and it might make you seriously consider unplugging everything when you’re not using it.