Vampire Power
Friday, March 11, 2011
To my shock and surprise, there was a lot of energy being wasted in my house. They say that vampire, phantom, or parasitic power, accounts for 10% of a typical American house electrical energy usage. It turns out my house's 154 watt vampire power was closer to 15% of my energy use or over $121 each year. What was using all that power?
Clocks, cordless phones, appliances in standby all use a little bit of power. Each one is almost negligible but add them all up and you get a pretty big energy wasting monster.
Most of these serve a useful function. The futuristic touch buttons and glowing clock on the microwave oven, or the ability to turn on a TV or open a garage door via remote control all add convenience and luxury to our lives. At the cost of a few watts we leave these devices running all the time.
I'm more than happy to consume a little power for a useful purpose and for more convenience and luxury.
After going around my whole house and measuring the energy that every light and appliance uses. I made a spreadsheet.
My largest consumer of stand-by power is my home theater receiver/amp. On stand-by, it draws over 64 watts. This wasn't included in my stand-by power calculation because I already had it on a power strip that I turn off when it is not in use.
My next largest consumer of stand-by power was my data-center equipment coming in at 44 watts. Cable modem, wireless router, Vonage box, 8-port Gigabit switch, 1TB NAS drive, TV antenna amp, and UPS backing it all up. Although technically not stand-by power, it is stuff I leave on 24-7 so I count it as such.
My biggest surprise was the central AC unit. Even when not in use, it still draws 33 watts. That may not seem like much but for something that is left on 24/7, that's huge! In one year's time, 33 watts will cost $26.00 (assuming 0.09/ kWh).
Most TVs made after 2009 are awesome at having low stand-by power. With the 1-watt initiative program in place, most manufactures are now on board at reducing this tiny draw that wastes a whole lot.
The furnace stand-by power is almost 10 watts. But what do you do about it? The fans are used nearly year around. Winter heating and summer cooling, I'll just have to eat that one. There is some control circuitry that receives its power from a loud buzzing transformer. Maybe I can swap it out with a more quiet and efficient one.
My house has a 3-car garage with 10' and 16' garage doors. The ultra quiet Martin Garage door openers use 7 and 8 watts respectively in stand-by. That seems kind of high to me but what can you do?
4 ½ watt stand-by power consumption for a network attached laser printer is actually pretty good. I can print to it from any PC in the house without any other PCs having to remain on to handle print jobs. For a house with multiple PCs, 4.5 watts is a steal for this service and convenience. But will it kill me to turn off the power switch on the printer until I need to print out something? Probably. So at the cost of $3.55/year, I'll leave it on.
After I knew what everything was consuming, I was able to make some decisions as to what was going to stay on and what was going off. My vampire power draw has gone down from 154 watts to only 99 watts. That's a 55 watt reduction or about $50/year. That is equivalent to 17 days/year of my solar panels making power.
Pretty good but I can do better.