Wasting Energy — Electricity utility business lives on “I’m off, really!”

Yesterday I got another shipment with electronics parts, which is almost better than Xmas. Among other things it contained a remarkably cheap energy meter. They’ve also got a link to a c’t-article about energy meters there. For readers of adafruit blog, it is similar to a “Kill-a-watt”, but for 220V 50Hz. This one only costs 9.95€ at reichelt.de and can measure powers from 0.2W to 3.6kW (220V single phase). It’s ideal for finding ‘fake standby’ devices. It measures line voltage (V), frequency (Hz), current (A), effective power (W), total energy consumption (kWh) and cost (€). The price per kWh can be adjusted. A nice feature is the lack of any battery.

As my back is killing my right now, I won’t be going anywhere anyways. So I might as well crawl around my home and measure how much energy I waste. Maybe this will bore the little devils sticking hot needles into my back to death and they go away. Even if walking upright was a major step in the evolution of mankind, it comes at a price…


The measurements:

activity hh:mm W off kWh cost comment
vacuum cleaning 0:45 1444 0.0 1.083
laundry @ 30°C 2:15 386 0.0 0.868
laundry dryer 1:43 1061 0.0 1.822
fridge 24:00 15.8 0.6 0.378
web surfing 1:00 137 7.0 0.137 standby ?

Wattages of some other devices:

device switch off standby idle job A job B
PC 1 0.0 7.0 102 157
DSL modem 0 3.0
speakers 1 3.5 7.5 7.5
19” LCD 1 0.5 0.6 34.0
8-port switch 0 2.8
HP 2605DN 1 0.0 14.8 28-35 285-584
750W microwave 1 0.0 1170
Adafruit Ice Clock 0 3.7

Now many folks may think that 10.5W of standby power isn’t a whole lot, but an average year has 8760 hours. Multiply that by 10.5W and you end up with 92kWh per year, senselessly wasted! According to my measurements that would be enough to have about 30 full loads of laundry washed and dried! If you like to think about it in terms of money, 92kWh would cost somewhere from 14€ to 24€ depending on where you get the juice. That’s definitely enough for going to the movies and maybe having some food as well.

Assuming that I’m “better” than average in terms of avoiding the standby trap, let’s just assume the average guy/dude/dudess/single/singless/family also has a big stereo, maybe an XBox or PS3 + TV, radio, alarm clock etc. etc. – all running on standby power. Let it be 50W total for sake of this thought experiment. Now take a country like the USA (0.30 milliard people, it’s NOT billion dudes!)

Short intermission:

See also here. BTW, short scale is crap and the world is metric!

Where was I… right the USA. Again 300 million people, maybe about 100 million households wasting the above assumed 50W. That’s a whoppin’ 120’000’000 kWh a day, 43’800’000’000 kWh a year or the output of a standard nuclear power plant (2GW) running for 2.5 years nonstop.

Fact: it takes about 334kJ to melt 1kg of ice of 0°C. Doing the math one gets: 1 kWh = 3600kWs = 3.6MJ, therefore the very large number from above gets multiplied by 3.6 to give MJ. Dividing that humongous number by 0.334MJ gives about 472 million tons of ice or roughly 0.5 km³, a cube with sides of about 800m. 800 meters are about the same size as the new Burj Khalifa sky scraper, which was completed earlier this year.

Gasoline has an energy content of about 38MJ/l. Wasting said amount of energy is equal to burning about 1’000’000’000 gallons of gasoline. That would take your average 25miles/gallon car 1’000’000 times around the globe.

All of this waste because of “I’m off, really!” a.k.a. “Standby”. Personally I’m more than willing to make the very small effort and switch off my gear when I don’t need it. Awareness to energy waste should be taught at school (and it could be fun too), as well as “Shut off the lights when you leave the room!”.


Mystery link!

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6 Responses to Wasting Energy — Electricity utility business lives on “I’m off, really!”

  1. Jan says:

    hm. thought about killing the biggest energy waster by far on your list (dryer)?

  2. robert says:

    Well, maybe I should get a drying rack then. That should work for the cotton towels at least.

  3. jan says:

    try to get a general-purpose drying rack (scnr)

  4. robert says:


    First I need to find one that doesn’t break after two weeks.

  5. marcus says:

    If you think 10W standby is high, consider how much energy you have embodied in all the things you have bought and discussed on just this blog.

  6. robert says:

    Yes, you got me there. But at least I don’t drive a HUMMER (and I never will). When my old car breaks down some day, I might even try living without an automobile. I’m an avid cyclist.

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