EcoLOGICAL Tip #8: Making ‘Ghost Loads’ Vanish

Trafton B.

December 12, 2010 - 4:01 PM

As much as this may sound like a Halloween time post, it was inspired by the current holiday season. With finals week over and done with, thankfully, it's time for students to head home and celebrate with the family. No matter how much time we spend packing and planning for our trips there is one thing that we seldom remember to do before locking up for the winter...unplugging the electrical devices.

Thursday morning I woke up and, knowing it was my last day in Eugene until after New Years, I closed up shop so to speak. I unplugged my computer cord and cell phone charger and tossed them in my luggage, locked all my windows, shut my blinds and brought my pepper plant downstairs in hopes that my roommates might water it every once in a while. Furthermore I unplugged the lamp on my nightstand and my mini-fridge, after emptying it of course, knowing that even while I'm away and even if any appliance isn't on it is still sucking electricity from the outlet it's plugged into, which brings me to the topic of today's ecological tip.

A ‘ghost load,' also known as a ‘phantom load' or ‘vampire load,' refers to electricity that is consumed when an electrical device is turned off or in standby mode. The most common culprits for a household's cumulative ghost load are things like televisions, DVD players, computers, cell phone chargers, printers, radios or microwaves. In short anything that is plugged in to an outlet is consuming electricity regardless of whether or not you are using it. For example, a cell phone charger consumes and average of 5-10 watts per hour when it is not connected to a cell phone.

The reason for this ‘ghost load' phenomenon is because any electrical device, battery charger or power strip is actually a miniature transformer that converts alternative current (AC) electricity from the wall outlet to direct current (DC) electricity to be used by the appliance. These battery chargers and power strips are essentially their own miniature electrical devices that needs electricity just like any other appliance, and, even though they only consume a small amount of electricity (3 - 20 watts per hour) by themselves, having several plugged in at the same time and running all day long can consume a significant amount of electricity.

Let's run a quick audit on my home. I have one power strip in my bedroom that supplies electricity for four devices - lamp, computer, phone charger and mini fridge. I'll assume that my roommates all have at least one power strip as well for their electrical devices. Plus two in the living room - one for the television, cable box, Nintendo and the other in the opposite corner we use for space heaters and occasionally for computer chargers when we want to work downstairs - and one more power strip in the kitchen for coffee maker, toaster and microwave. That brings us up to nine power strips, but I'm going to round up to ten for a cautionary overestimate.

When I did the math, multiplying watt-hours of phantom load by time in hours and electrical devices plugged in, I found that on a monthly basis my household's phantom electrical consumption is very typical.

The low estimate for ghost consumption was 22 kWh (kilowatt hours), and the high estimate was 144 kWh. A large discrepancy, I know, but these are very rough estimates. Considering that my household consumed 1,685 kWh of electricity in November that means that between 1.3% and 8.5% of our electrical bill is being caused by electricity that we don't actually use, and I suspect that my high estimate is closer to the truth because I'm not counting miscellaneous electrical outlets being occupied throughout the house or the several larger appliances that can add to the load, such as dishwasher, oven, or washer and dryer. All the textbooks and online articles I've read claim that ghost electrical consumption contribute between 10% to 15% of the total electrical consumption. 

Okay, enough numbers, this is supposed to be winter break after all. Plus, it's no fun to focus on the negative when we still have a solution to discuss. The solution is simple. Find power strips with an on/off switch. If you're really adventurous try to find power strips with occupancy sensors as well. We have about sixty Watt Stopper Isolé IDP-3050 Power Strips with motion sensors at Facility Services. One of my first projects last year was trying to convince professors and staff members to install them in their personal offices. I wasn't met with much enthusiasm around campus, but I still push to topic around Facilities.

If anyone is still reading then I'll treat you with a humorous ‘how to' movie about installing Smart Power Strips. I like these products because they are even simpler than normal on/off power strips and less precarious than the motion sensor controlled Watt Stoppers.

That's all for now. I hope you've enjoyed this week's EcoLOGICAL Tip. Thanks for tuning in.