Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall.
Today, we have a question from a listener.
Michael: Hi, I’m Michael, I’m from Charlestown, Rhode Island. My question is: Does a charger still use some power when it’s plugged into an outlet but not connected to a phone or other device?
Megan Hall: Thanks for the question, Michael! We had Kolya Shields and Ashley Junger from our Possibly Team look into this. Welcome, Kolya and Ashley!
Kolya Shields: Hi, Megan!
Ashley Junger: Hello!
Megan Hall: So, are the chargers all around my house using electricity right now?
Kolya Shields: The short answer is yes. To find out more, I spoke with Arthur Shi, who is an electrical engineer and technical writer at iFixit, a technology repair company.
Arthur Shi: “Most appliances use a bit of power when they’re plugged in. This is known as idle load or standby power or vampire power”
Ashley Junger: So this includes things like washers, dryers, and TVs, but also things like phone chargers, with or without a phone plugged in!
Megan Hall: So Michael asked about when a charger is plugged in with no device attached. How big a deal is that alone?
Ashley Junger: Small chargers without devices really don’t have much of an impact. According to research out of Berkeley Labs, a wall charger without a phone plugged uses about .26 Watts.
Megan Hall: Is that .26 Watts a minute?
Ashley Junger: No. An hour. It’s not very much. Let’s put it this way- if the charger is plugged in for the entire year, it would only use about 30 cents worth of electricity.
Kolya Shields: But other devices use much more energy, and those amounts can add up quickly. Arthur actually did some tests for us with a power meter to find the biggest energy sucks around his house.
Arthur Shi: Microwave was using three watts at idle. My internet router, and modem, we’re definitely using a lot more, there are about six to eight watts, each. The one that I found out used the most was the TV. When it was on active standby. It was pulling 37 watts of power, because it was ready to be turned on at a moment’s notice.
Megan Hall: 37 watts just sitting there! That sounds like a lot.
Ashley Junger: It is. To put that in context, the average hourly standby power use of an entire house is around 164 watts, meaning that his TV alone was probably responsible for about a quarter of that power use.
Megan Hall: Why do some devices use more energy than others? I mean, all of them are just sitting there.
Kolya Shields: Arthur said it depends on age and connectivity. For example, new smart devices like Alexa are constantly connected to the internet and pulling power.
Megan Hall: So how big a deal is this so-called “Vampire Energy”? It can’t end up being that much electricity, right?
Ashley Junger: Actually, vampire energy is a big deal! It accounts for about a quarter of all residential energy use.
Kolya Shields: That equals about 19 billion dollars worth of energy each year—or about 165 dollars per U.S. household on average.
Megan Hall: So, going back to Mike’s question, do I really need to unplug my phone charger whenever I’m not using it?
Kolya Shields: Unplugging chargers will save you a little energy, but to be a real vampire-slayer, you should focus on the devices that use the most idle energy, like TVs and smart devices!
Ashley Junger: Hooking multiple devices to one power strip and turning it off at the end of your day is an easy way to speed this process up.
Kolya Shields: And if you want to cut down on your energy use even more, Arthur recommends doing a home energy audit, where you figure out which devices and appliances have the biggest power load.
Megan Hall: Awesome! Thanks, Kolya and Ashley!
That’s it for today. For more information, or to ask a question about the way your choices affect our planet, go to the public’s radio dot org slash possibly. Or subscribe to us wherever you get your podcasts.
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Possibly is a co-production of the Institute at Brown for Environment and Society, Brown’s Climate Solutions Initiative, and the Public’s Radio.