“Vampire loads,” “Phantom Loads,” or “Standby loads” are the power that devices use when you are not using them. Yes, frustratingly, every time you leave a computer, coffee maker, or TV plugged in but are not using it, you are wasting energy. Outrageous, yes. But true. It takes power just to keep those devices ready for when you need them. You even waste energy when you leave a charger plugged into a wall but are not charging anything because of something called transformer losses. That wasted energy is what makes chargers hot even when nothing is plugged into them.
So how much energy are we wasting? It depends upon the device. Fortunately, the good people at Lawrence Berkeley Laboratory and elsewhere have done a great deal of research and compiled a table of average standby power losses.
How do I use this table? How much energy and carbon am I wasting? Well, we start by multiplying the hours we do not use the device by the watts in the table. Odds are, we are not using the device most of the year (say 80% of the time). For example, if we look at an average desktop computer that is asleep instead of shut off:
• 21.13 Watts in sleep mode – 2.84 Watts off = 18.29 Watts wasted
• 8,760 hours per year * 80% = 7008 hours per year wasted
• 18.29 Watts * 7008 hours = 128,176 Watt-hours = 128 kWh per year wasted
A kilowatt-hour (kWh) is a measure of energy. 128 kWh is not actually a lot of energy – it would cost anywhere from $10-$30 depending upon where you live and what time of day you use your computer. But there are over one billion computers in use in the world and hundreds of billions of appliances, and together they comprise a vampire army.
What’s their environmental impact? Well, every region of the world gets its power from a unique combination of different energy sources – coal, gas, wind, nuclear, etc. – and therefore has a unique carbon intensity. Fortunately, the Department of Energy and the Environmental Protection Agency come through again! They collect enormous amounts of data which our non-profit partner Carbon Lighthouse Association has summarized in a simple table. To use the chart, take the “kWh wasted” number from above and multiply by the right column (Lbs CO2/kWh) to get the pounds of CO2 wasted. (Note to our international readers: unfortunately we have not yet compiled region specific data for countries outside the US, but we will!) Continuing our example, we can find the wasted carbon emissions resulting from our desktop computer in the state of Delaware:
• 128 kWh/year * 1.71 Lbs. CO2/kWh = 219 pounds of carbon wasted every year
You can calculate the approximate dollars wasted, too, by multiplying the kWh wasted by the middle column (cents/kWh) and dividing by 100. Using the desktop computer example in Delaware:
• 128 kWh/year * $0.14/kWh = $17.92 wasted every year (and probably other savings, too)
So what can you do to slay the vampires?
Power strips! You may have encountered these devices from situations such as: “there’s only one outlet in the room and I have a printer, monitor, computer, phone charger, and lamp” or “The hardware store clerk mumbled something about surge protection,” but power strips are much more. They are vampire slayers, as heroic as anything out of Sunnydale. Energy use from “plug loads” – devices you plug into a wall socket – is growing dramatically around the world. Minimizing the energy those devices use will be an important part of building a sustainable planet.
There are several types of power strip types and they each are used slightly differently.
1. Manual: The traditional power strip. Flick the power strip switch off when you’re done using your devices. In your home, flick it before bed. In the office, flick it at the end of the work day.
2. Timer: You program the power strip and it turns off all devices on the strip as programmed. Great if you use a device on a regular schedule (i.e. you watch television nightly from 9-10 pm)
3. Individual Smart Strip: When power flowing through a socket on the power strip falls below a certain level (about 30 Watts), because your computer has switched from work mode to sleep mode, the power strip shuts off the circuit thereby shutting down your computer. Works automatically.
4. Master Smart Strip: When power flowing through a selected (“master”) socket on the power strip falls below a certain level, because your computer has switched from on mode to sleep, it shuts off all the peripheral devices plugged into the power strip (monitor, lamp, printer, etc.). Works automatically. Great for office devices.
5. Motion Detector: When the passive infrared sensors on the smart strip no longer detect motion, the power strip turns off. You program how sensitive you want it the strip to be, whether it must detect motion every 30 seconds or every half hour. You walk away, it turns everything off.
So where do I sign up? It’s actually all quite easy.
• Identify places in your home or office where there are lots of devices plugged into a wall
• Buy a power strip
• Put those devices on a power strip
• Use the power strip according to one of the strategies above.
• Voila. Money saved. Carbon reduced. Vampires slayed.