JOHN YANG: A lot of us leave electronic devices plugged in when we're not using them and don't give it a second thought.

But many everyday items can drain energy even when they're turned off.

Things like coffee machines, video game consoles and laptop chargers.

They account for between 5 and 10 percent of nationwide home energy use.

Stephanie Sy spoke with Alexis Abramson, Dean and Professor at the Climate School in Columbia University, to learn more about the effect of these so called vampire devices.

STEPHANIE SY: Alexis, thank you so much for joining us.

So what exactly is a vampire device and what are some of the everyday culprits we might find in our homes?

ALEXIS ABRAMSON, Columbia University: So vampire are sometimes called phantom load devices essentially are devices that consume electricity when they're plugged in, but maybe not actively in use.

So they might appear off, but they're still drawing a small amount of electricity.

So TVs are common culprits, game consoles, streaming devices, computers, monitors, printers, even phone and laptop chargers and smart appliances, coffee makers, microwaves with those clocks on them all can contribute to phantom loads.

STEPHANIE SY: One quick question.

If you turn off a power strip, is it still drawing energy as well?

ALEXIS ABRAMSON: Usually not.

So a power strip is usually not drawing much, maybe a tiny amount of electricity when it's off.

But today there are things called smart power strips or smart plugs, and you can actually program those to turn on and off in various parts of the day.

So maybe you leave the office at 6:00 p.m.

you come back in at 8:00 a.m.

and they actually can be programmed to be completely off or near completely off during that time period.

STEPHANIE SY: So how much energy is being wasted this way?

ALEXIS ABRAMSON: So, relatively speaking, it's a small amount of energy per electronic device or per appliance.

So we're talking about maybe 5 percent, maybe up to 10 percent of a total household's electricity use might be attributed to this phantom or vampire load.

But for some homes, that can really be about $100, maybe to $200 annually.

So overall, it can actually be a pretty substantial amount.

STEPHANIE SY: Are manufacturers in any way pressured to redesign their products so that there aren't these sort of phantom extra energy systems that continue to run even when we're not actively using the appliances?

ALEXIS ABRAMSON: Yes, absolutely.

So manufacturers are more and more designing different features to make sure that either the consumer has the ability to turn things off, like really turn things off, or make sure they have the ability to put things in more of a sleep mode when possible.

STEPHANIE SY: Ultimately, though, when it comes to the environment and in particularly climate change, how much of a difference would it make if everyone became more conscientious about unplugging devices that they don't use?

ALEXIS ABRAMSON: So with respect to climate change, every electron saved is a reduction in the greenhouse gas emissions, usually that goes into the atmosphere, and therefore that we have to worry about from a climate change perspective.

So, if we can just avoid the use of the energy, then that is the best way possible in order to avoid the greenhouse gas emissions that fossil fuel power plants generate to provide electricity.

If everybody in the country could do just a little bit of something, we would then be able to reduce that total energy consumption and thereby help mitigate the climate crisis.

STEPHANIE SY: And what are some basic steps that somebody can do right away to ensure that their vampire devices in their homes are not sucking more energy than they need?

ALEXIS ABRAMSON: Probably the easiest thing that people can do is unplug devices when they're not in use.

This includes things like cell phone chargers.

Oftentimes we leave those chargers plugged into the wall, and many of them can draw some electricity, even when that phone isn't charging.

Another thing to be able to do is if you have some kind of wall switch, you know, you can use that wall switch to turn that device on and off.

The maybe the next step is to be able to use smart power strips or smart plugs.

And then the other thing is when you're in need of a new appliance or a new electronic device, just make sure you're looking for that Energy Star label when you're walking into that big box store.

It will cut costs on your monthly electricity bill and really help the world in a way that you're not emitting more greenhouse gases than you absolutely have to.

STEPHANIE SY: That is Alexis Abramson with Columbia's Climate School.

Thank you so much for joining us.

ALEXIS ABRAMSON: Thank you very much.

Happy to be here.