No, it's not the latest summer B-movie. It's not a Red Bull knockoff for goths. It's the electricity your appliances keep sucking down even when they're turned "off". (Also called standby power.) Sometimes it's surprisingly large: a DVD player might use 75% as much power when off as when on, and the average desktop computer sucks down 35 watts when in standby. For the latest numbers on all kinds of appliances, check out the Australian government's report on standby power. Anything with a transformer, such as chargers for mobile devices or computer power supplies, keep using power whenever they are plugged in. Sometimes it's just a watt or two, but sometimes it's much higher. As GrinningPlanet points out, this still only amounts to 10% of most people's energy bills, but that still adds up, particularly in an office. Vampire power is an issue that's been known for quite a while, but industry is accelerating on things you can do to stop it.
How do you know if your innocent-looking printer is secretly a vampire? We've mentioned the Kill-A-Watt power meter before, and hardcore geeks can get things like the Watts Up meter, which has the ability to log consumption data over time and send it to your computer, so you can chart daily / yearly variations to see if your consumption patterns would match different power generation methods. (For instance, photovoltaics in your home generate most of their power during the day, when you're probably off at work and thus not using much power at home.) Building contractors can put in professional-grade meters for monitoring whole circuits in buildings. But for testing vampire power at home or in the office, a Kill-A-Watt will do you just fine. And if you can't afford that, build your own.
Once you know you have a vampire, what can you do about it? One thing you can do is replace it. For manufacturers reading this, a company called Power Integrations makes chips which you can use in your power supplies to reduce standby power drain by 75-90%. For consumers reading this, getting an EnergyStar certified device usually helps, sometimes a great deal. You can search by category (computer, audio equipment, etc.) at LBL's website, and you'll find there's a lot out there. But many manufacturers don't go that extra mile for you, and you may not be willing to part with what you've got (either for functional, sentimental, or non-landfilling reasons). What can you do if replacement isn't an option?
If you have one device that does standby well, you can use it to trigger a power strip that shuts off other devices. Smart Strip by Bits Limited monitors one outlet, and when the device plugged into that outlet starts to use much less power because it's gone into power-saving mode, the Smart Strip shuts off the other outlets (though it also has a couple always-on outlets if you need them). Then when the triggering device ramps back up to high power use, the other outlets get switched back on. I have one, and it'd be perfect for desktop computer users with the normal complement of monitor, printer, external drive, or other peripherals. I was hoping it'd be useful for my stereo too, but there isn't enough difference between idle and on, which is all the more evidence that I need to intervene there.
If you don't have anything that stands by well, you can use occupancy sensors to shut things off when you're not in the room. The Wattstopper eliminates the need for rewiring your house or hacking your plugs--it is a power strip that comes with an occupancy sensor to turn all but two of its outlets on and off.
Of course, you can always just unplug things, or have them plugged into a power strip which you manually turn off. This is the cheapest method, but requires the most diligence. Still easier than a wooden stake through the heart, though. Happy vampire killing!
