Note: This story was updated on May 7 to add information from a study released by the National Resources Defense Council on that date.
You shut down your computer. You turn off your TV. You take the popcorn out of the microwave. And yet all of these devices and more continue to suck electricity.
This vampire power, also called phantom power, idle load, or standby power, keeps going even after the device is turned off. How much does it waste? Hundreds of dollars per year, according to some estimates. In fact, the Natural Resources Defense Council (NRDC) published a study after this story was first published indicating that vampire power cost $19 billion per year—about $165 per U.S. household. The report estimates that “idle load electricity represents on average nearly 23 percent of household electricity consumption in northern California homes.”
But the numbers are difficult to pin down. Alan Meier, a senior scientist at the Lawrence Berkeley National Laboratory estimated “that we’re somewhere on the order of five percent.” He described that as a “hunch.”
I can’t test everyone. So I set out to find out which devices in my own home waste electricity when they’re not used, and how much they waste. These are my results.
What exactly is vampire power?
When you turn a modern device “off,” it probably stays on in a low-power mode. Common culprits include computers, HDTVs, A/V receivers, printers, and your microwave. Any one such device isn’t going to use up a lot of power. But if you have 10 or 20, the waste builds.
It’s called vampire power because when it’s supposed to be dead, it still sucks.
Three signs can tell you without a doubt that a turned-off device is using juice:
2. You can turn it on or give it a command from a remote control, a smartphone, or over a network.
3. It knows the time as soon as it comes on.
But I won’t give the designation vampire to everything that matches one of these attributes. While a device needs power to do any of these, it doesn’t have to use much. Some really use so little power that it’s inconsequential.
Quick definition: A watt hour (Wh) is a measurement for wattage used over time. For instance, if you leave a 40-watt lightbulb on for one hour, you will use 40Wh. A kilowatt hour (KWh) is, of course, 1000Wh.
According to a U.S. Energy Information Administration report, in February Americans on average paid 12 cents per KWh. But the average in Washington state was only 9 cents per KWh—the lowest in the country. The highest? Hawaii, at 31 cents a KWh (so much for paradise).
How I measured vampire power
To find out what I’m wasting, I tested my Windows laptop, my wife’s Mac, our HDTV, our phone and tablet chargers, our network, and assorted peripherals. I did not test our microwave. It’s a built-in, and I have no access to the plug.
Please note that my devices are not all the latest and greatest. Some are very out of date.
I plugged whatever I was testing into a Watts Up Pro power meter, waited for a few minutes (considerably more for a laptop with a battery), reset the meter, then left it undisturbed for at least six hours. At the end of the test, I noted the meter’s Wh per month estimate. Because of the very small amounts of electricity concerned, I felt it provided the most accurate and readable results.
I’ll abbreviate these results as Whm, for Watt hours per month. Keep in mind that this number is a very lose estimate of what the device will suck if you left it plugged in but unused for a month.
The smaller the trickle of electricity, the less reliable the Watts Up Pro becomes. If it estimates that a device pulls 0.5Whm, you really don’t know what it pulls, except that it’s inconsequential. So when the meter estimates a monthly estimate of less than one watt hour, I’ll mark it as 0+.
Surge protectors, smart and dumb
Surge protectors play a major role in consuming and fighting standby power. You plug many vampire devices into them. They can be vampires themselves. But they can also be valuable tools for conserving power.
Green surge protectors, also known as smart surge protectors, can help keep waste to a minimum. With these, when your computer or television is on, the peripherals around it get the power they need. When it’s off, the surge protector cuts off their source.
A smart surge protector has three types of outlets:
1. A single Control outlet where you plug in the primary device, such as the computer or TV.
2. Multiple Switched outlets that are turned off by default. Devices plugged into them only get power when whatever is plugged into the Control outlet is turned on.
3. The Always on outlets work like they’re on a conventional surge protector. Plug a vampire into one of these and it will continue to suck.
Smart surge protectors definitely save power—often a significant amount. But they also tend to use power—although not as much as they save.
I tested four surge protectors, three of them green models:
My not-so-smart, conventional surge protector is a Belkin BE106000-08R. It burned 0+ Whm. It might actually burn 0, as it doesn’t have an LED.
My tests showed an odd anomaly with all three green surge protectors. Once I plugged a single device into one, the meter showed a result significantly higher number than one would expect from the combined pull of the surge protector and the device. I have not been able to find an explanation. I suspect that the smart surge protectors need some power to think.
But when used correctly, smart surge protectors can save a lot of power. My tests showed savings of eight to nearly 15KWh (that’s kilowatt hours) each month.
The biggest culprits: TVs and accessories
Your home theater can easily turn into a coven of vampires. You’ve got a TV, an A/V receiver, various players, probably a powered subwoofer, and maybe a DVR. Some of them need to know the time, some don’t’ even have a standby mode, and most of them respond to a remote control,
I keep my television plugged into the Control outlet of my Rocketfish green surge. My receiver, subwoofer, Blu-ray player, LaserDisc player, Roku Streaming Stick, and Chromecast are plugged into Switched sockets. I have a lamp plugged into an always-on outlet.
That configuration sucks 564Whm. Almost all of that is the surge protector’s own overhead.
But it’s worth it. When I plugged all of those devices into a conventional surge protector, my meter estimated more than 15KWh a month—almost 30 times what the Rocketfish burned.
What caused that waste?
Certainly not my HDTV, a very out-of-date Sony KDS-50A2000. It scored 0+, proving that you don’t need much power to react to a remote control.
About half of the waste went into my Cambridge Soundworks BaseCube 10 subwoofer, which pulled more than 7KWh a month. But almost everything there pulled more than it should have.
In fact, the only non-vampire in the group, the only other 0+, was my Sony BDPS3200 Blu-ray player—and that was only when I turned off the Fast Start option.
My power consumption would probably be much worse if I had a DVR. These can be amongst the worst vampires around, often using almost as much power in standby mode as when they’re on.
To make things worse, a DVR needs power 24/7 so it can wake up and start recording at scheduled times. Therefore, you can’t plug one into a smart surge protector’s Switched outlet.
That would be acceptable if they used a reasonable standby mode, but I’ve yet to test one that did. Back in 2010, I tested a Dish Network DVR and found that it sucked about 53 watts in standby mode. That’s about about 38KWh a month with no recording or viewing. Last year I tested the Simple.TV, and while it proved more efficient than the older DVR, it still sucked 9- to 12 watts in standby mode. Consider that 7- to 8KWh a month.
Computers and peripherals
A modern computer has multiple states of being turned “off.” Most of them are vampire modes.
Windows has three options for shutting down and saving power. I tested all three on my main computer, a Lenovo ThinkPad X220 laptop.
Sleep mode shuts down the hard drive, the screen or screens, and various internal functions. But much of the hardware stays on so you can quickly return to where you were.
My laptop would burn about 67Wh if I left it in sleep mode for a month. That’s reasonable.
Shut down ends the Windows session, then almost completely turns off the hardware. My Lenovo only burned 5Whm. That’s pretty close to nothing.
Hibernate is a compromise between sleep mode and shut down. It turns off the hardware almost as completely as a shut down, but like sleep, it can return you to where you left off. My X220 burned about 16Whm—significantly more than shut down but still much better than sleep.
I usually keep this laptop plugged into a Lenovo UltraBase 3 docking station, which is plugged into the Belkin Conserve Smart AV surge protector. My external monitor, scanner, and speakers are plugged into the Belkin’s switched sockets.
The meter told me that the surge protector burned 635Whm with everything plugged into it. Yes, that’s way too high. Only the laptop, the docking station, and the surge protector should be pulling anything, and the three of them combined shouldn’t be much more than 5Whm. The docking station, like the surge protector, pulls an inconsequential 0+ when empty, but it burned 363Whm with the X220 plugged into it. The rest came from the green surge protector anomaly discussed above.
But that bit of waste is nothing compared to what happened when I plugged everything into the conventional surge protector. Between the laptop, the docking station, the monitor, the speakers, and the scanner, it pulled about 8.75 kilowatt hours a month.
Once again, the biggest vampire included a subwoofer. My Altec Lansing VS4221 2.1 Speaker System pulled more than 5KWh per month.
Only my monitor, an LG 22EN43T-B, uses too little to be measured.
As for my wife’s MacBook Pro, in sleep mode, it ran a surprisingly high 376Whm. It’s clearly a light sleeper. But when I shut it down completely, the power consumption went down to 0+. The Mac doesn’t hibernate.
Smartphones tablets, and AC adapters
If you own an Android device, you’ve likely unplugged it from its micro USB charger and seen a message telling you to unplug your charger to conserve energy.
Guess what? You really don’t need to.
This used to be a big deal. You had to assume that anything that used an external AC adapter wasted power. But with the proliferation of micro USB adapters, and generally better designs, the power pulled by these devices became insignificant.
I tested the Micro USB cord and adapter for my Android phone, the Apple adapter and 30-pin cable for my iPad 2, and the power brick for my Lenovo laptop. All of them came up 0+. As far as I know, some may be a perfect 0.
Like a DVR, you can’t really shut down your modem and router—at least if you live with other people. Someone might be burning the midnight electrons to complete an assignment.
That’s why my router and modem are plugged into a conventional surge protector that almost never gets turned off. We also keep two networked printers plugged into that same surge protector. (Why two? The laser printer is faster and cheaper to use. The inkjet has color.)
And it’s wasteful. The surge protector, with the modem and router in it, burned an estimated 4.8KWh a month with nothing on that would use the Internet or the local network. When I plugged in the printers, the waste jumped to more than 12KWh a month.
Maybe I’ll start turning off that surge protector at night. Or perhaps I’ll start using another type of green surge protector—the kind with a timer.
Giving up power
By my estimates, I waste about 13KWh a month—mostly due to my network and printers. If I replaced my green surge protectors with conventional ones, I’d waste about 32KWh a month. That’s about four percent of the 909KWh national average. And that’s not including my microwave. Or the DVR I don’t even own.
Wasting electricity is bad for your pocketbook, and bad for the planet. It’s best to take whatever reasonable steps you can to reduce waste.
But really, this responsibility shouldn’t be exclusively on the consumer. If devices were built to be more efficient when off, there wouldn’t be so big a problem. Perhaps we can get Professor Van Helsing to work on product design.
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