Did you know that cell phone chargers use power if they are left plugged in and not charging a phone. That is true of most electrical appliances that are plugged in but turned “off”. They still draw a charge. I was reading through this online accounting of a small business trying to account for and reduce it’s energy use and stumbled across this little bit of information regarding cell phone chargers. The one tested in this case was using 3 watts of energy when plugged in and not charging. Some people may think 3 watts is nothing to worry about. But lets do the math: According to the U.S. Census Bureau the number of cell phone subscribers in the United States reached approximately 159 million in 2003. I’m sure it’s a few million more today. Imagine that most of these folks leave their chargers plugged in, let’s say 130 million (remember this is U.S. only). Assuming folks plug in and charge every day for 8 hours (I’d guess most charge every other day or less) we could say that 130 million chargers are wasting 2-3 watts 16 hours a day. That’s a range of 260 to 390 million watts of energy a day wasted which translates into 260,000 – 390,000 kWh (1 kilowatt-hour (kWh) = 1,000 Watts) a day.
Looking at this post at treehugger about this very subject I see these comments:
FWIW, following this post I went and hooked up my “Kill-A-Watt” monitor to my cell phone charger. The results are in: 0.04 kWh over 308 hours. That is, I left the charger plugged in for 308 hours, and attached my phone whenever it got low.
At that rate my total kWh for the year is going to be 1.1
I understand that there are a lot of “bad” adapters out there, but maybe they are the big, heavy, hot things attached to cheap computer equipment. I saved an 8 watt continuous pull by dropping my powered computer speakers, for instance.
okay, so it’s “only” 1.1 kwH per year. that’s for one charger for one cell phone. let’s extrapolate: the population of canada is 32 million. sure, not everyone has a cell phone, but there are a LOT of ppl with two, three, or more of the things. if everybody wastes “only” 1.1 kwh per year, do the math: 32.3 MILLION kilowatt hours wasted per year!
i just did the math:
one barrel of oil = 1640.8KWh
therefore, if 32 million cell phone charger adapters were left plugged in and wasting 1.1 KWh/year, that’s
196,977.08 barrels of oil wasted!
Math makes my head hurt so I’ll stop with the numbers. The point is, it’s a lot of wasted energy and a lot of Carbon being pumped into the atmosphere to power unused devices. Via CNN there is this:
Keeping your cell phone and battery charger plugged in may cost you $1.50 a month and the night light? That’ll cost you $.50 a month if you keep it on 24/7. On a national scale, the Alliance to Save Energy estimates that on a national level, these vampire devices use about 5 percent of our energy and cost consumers more than $8 billion annually.
Best of all is this page at the U.S. Department of Energy’s Energy Efficiency and Renewable Energy which details the power usage of all sorts of home appliances.