Chargers and Converters

My family is away this week, so I’ve been playing with vampires. It’s not as kinky as it sounds. “Vampires” is the nickname for all of the nasty little electrical devices that suck juice from your electrical outlets even when they are supposedly off. The most common vampires are televisions and computer equipment in standby mode and battery chargers that are left plugged in even when they are idle.

I wanted to know how much these little suckers use in my house. Does their electrical consumption add up to something significant? The municipal electric meter was my measuring device. With no one else in the house to surreptitiously turn on a light, I could control exactly what was and was not drawing power.

First, to establish a baseline, I switched off all lights and geysers, and I unplugged everything, including the refrigerator. Over two hours, I used just under 0.2 kilowatt hours of electricity. I assume that means my security system draws a little bit less than 100 watts.

Then I plugged in every cellphone charger, battery charger and toothbrush charger I could find. I turned on two televisions at the switch and then zapped them “off” with their remotes, and I did the same with any video devices attached to them. I powered up the stereo amp and CD player. I plugged in my electric piano, but left it off. I booted up computers-then put them into standby mode-and I plugged in any printers or other peripheral attached to them. Finally, I plugged in two voltage converters that I use for a few appliances I brought over from America.

I want to emphasize that I was not using any of these devices. I wasn’t watching TV, listening to music or using a computer. None of the chargers had anything to charge. Nothing was plugged into the voltage converters. The lights stayed off and the fridge remained unplugged. The house was as dark and silent as you might expect it late at night when we are all asleep.

Two hours later, my municipal meter told me that I had used 0.5 kilowatt hours, which means that those thirsty little vampires were cumulatively lapping up 150 watts to do absolutely nothing. Left alone, that’s 3.6 kWh a day or 108 kWh a month, costing nearly R34 at Johannesburg’s electricity tariff. Over a year, I could be using 1 314 kWh, pumping well over a ton of carbon dioxide into the atmosphere and paying R410 for the privilege. It’s like having a leaky faucet that drips around the clock, but it’s leaking electricity instead of water.

Was my scenario extreme? Perhaps a little. Most people don’t have voltage converters. But otherwise our family lives like many suburban South Africans. Studies quoted by the Economist magazine in an article last year found that vampires account for 7 percent of domestic electricity consumption in France and up to 10 percent in some American homes. Vampires in the U.S. alone drink up the equivalent output of 18 typical power stations, according to the Economist.

I am sure that my family does not use all of those 150 watts as we sleep. My children know that remotes are for changing channels, not for switching televisions on and off; that’s the function of the button on the front of the TV. I turn my PC all the way off when finished using it, reaching behind the case to the switch at the back. And I only plug in chargers when they have a job to do. But this exercise did make me realize that there were gaps in my vigilance. I noticed that even when my electric piano was off, its AC/DC transformer at the wall was very warm, a sure sign that it was wasting power. From today, I have decided to switch the piano off at the wall when I’m not playing it. I will sleep better knowing that I have slain another vampire.