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The True Cost of Standby Power
Luther19 writes, "How much do all of our computers and electronic devices sitting in standby mode cost us? The author of the article concludes that he could save $24.44 per year by switching out wasteful power supplies. The article also touches on a global initiative to cut down on standby power, called '1-Watt': 'The idea has been promoted by the IEA, which first developed an international 1-Watt plan back in 1999. Countries like Australia and Korea have signed on officially, while countries like the US require 1-Watt in government procurement, which will have ripple effects throughout the economy. The goal of the program is to have standby power usage fall below 1W in all products by 2010.'" It's estimated that in industrialized countries, devices on standby consume on average 4% of the power used.
The way we engineers do it is by pareto analysis - you try to cut out of the largest portion of your power consumption. I'd like to see what lines up as the numbers one two and three consumers of electricity, and how that compares to the cited 4%, and how much was saved by going to standby mode as it stands today. I'm guessing that there are better places to focus the effort, but perhaps that's just my own bias.
Quiz: True or False -- On a scale of 1 to 10, what is your middle name?
I'm not sure the effort and materials costs associated with replacing a power supply are worth $24 per year...
I caught the Mountain Wumpus! He gave me his treasure chest ($100) to let him go free again.
Mind you: it's not always a device with an explicit stand-by mode. I once used such a wattmeter on all devices and learned that my 40W lamp with a seemingly #$%#$% cheap transformer was using 25W while "off"!
:S
Factoid: if all American households would not use the stand-by mode of their TV, an entire _nuclear_ power plant can be saved on a national level.
I just finished a comprehensive audit of all the electricity drawing devices in my house:
o ld_energ.html
:-)
http://digitalcrusader.ca/archives/2006/10/househ
I learned that my Stereo system consumes 22W when on "standby" and only about 35W when in use - what a total waste! So I put it on a power bar. My older TV is 0W standby, and all the newer Wall Warts that I have seem to be OK as well - 4 of them together only rate 1W. Your milege may vary
augment your senses: http://sensebridge.net/
I know Georgia Tech went on a campaign a few years back to replace as many incandescent bulbs as possible.
As part of it they replaced all of the 300 watt bulbs in the Van Leer build (old EE building) with 20 watt fluorescent lamps. Each lab probably had 10-15 twenty of these power hogs. After the switch our labs were freezing cold! All that extra cooling wasn't needed any more.
Over the course of a year it saves the institute over 2 million dollars. the first million was in direct power reduction, the second million was due to reduction in cooling cost.
I can tell your from experience (this is one of the more popular demonstrations in the power engineering lab) that cheap watt-meters can be terribly wrong with loads that are not simple resistors.
A transformer with no load (probably in your case - most lamps with halogen lamps have the switch on the secondary side) is almost a perfect inductive load. Current and voltage are not in sync and the (real) power is very close to zero.
Not all instruments can show this correctly. Especially not if they measure voltage and current separately without taking the phase shift in account (as is often the case with cheap stuff). Switching power supplies (almost everything electronic uses one of those today) are also hard to measure. You need a high sampling frequency if you want to accurately measure the power they draw from the mains. Again, consumer instruments don't have this because fast AD converters are expensive.
Just about the _only_ instrument I would trust outside the lab is the watt-meter the power distribution company installed in your house. These things have to go through very thorough testing before they are approved.