# Energy Cost of Idling Electronics **URL:** \ **Category:** Factual Questions\ **Created:** [March 9, 2001, 3:35am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302 "2001-03-09T03:35:18Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Briny\_Deep](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/briny_deep/32/17188_2.png) [@Briny\_Deep](https://boards.straightdope.com/u/Briny_Deep)\ **Post date:** [March 9, 2001, 3:35am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/1 "2001-03-09T03:35:18Z")
Does anyone have an educated guess as to the amount of electricity consumed by electronic music equipment that is on, but not being used? Specifically, I’m talking about a big Roland KC-500 keyboard amp, an 88 key controller keyboard, and sound module. I play it sometimes, but leave it all on 24/7; my roommate, also a musician, comes along and shuts it all off to “save power.” I maintain that while the equipment isn’t actually being played, the power draw is miniscule - I’m guessing, less than that of a nightlight. Is there much energy savings to be gained by not leaving the stuff on all the time? ---
**Author:** ![Ice\_Wolf](https://avatars.discourse-cdn.com/v4/letter/i/dfb087/32.png) [@Ice\_Wolf](https://boards.straightdope.com/u/Ice_Wolf)\ **Post date:** [March 9, 2001, 4:02am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/2 "2001-03-09T04:02:03Z")
Here in New Zealand, we have a consumer TV programme that discussed this kind of thing just this week. The cost of leaving appliances on “stand by”, per appliance, ranges from NZ$4 to NZ$6 per year (the worst culprit, they said, was leaving the microwave on to tell the time. Said that uses more energy than the actual cooking). 'Cause we’re just Kiwis down here, I’d say your costs wouldn’t be that much different, even with the exchange rate. Your power rates could be murder! ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [March 9, 2001, 4:03am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/3 "2001-03-09T04:03:58Z")
Well…there are three things you can try: 1. Write, or call the manufacturer. Many of them have specs on the power consumption when just on, and not in use. 2. Use an ammeter to determine what the amp draw is. 3. Well…ok, let’s WAG. To do this, let’s find out some things: a) What is the power supply - is it an AC/DC transformer? If so, the maximum wattage and/or amperage is likely marked on the transformer (the big box inline with the power cable). b) What power does the equipment use when played? This, of course, gives an upper bound. c) If it has any lights, you can estimate draw for each light on. In other words…hmm, I guess this is not a very helpful post then. Being the experimentalist I am, I would choose option (2) to find out. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [March 9, 2001, 4:11am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/4 "2001-03-09T04:11:21Z")
> [@](#): > > \*Originally posted by Ice Wolf \* > **(the worst culprit, they said, was leaving the microwave on to tell the time. Said that uses more energy than the actual cooking)** Well, they may say that my Kiwi friend, but I simply cannot believe that at all. I would love to see if anyone could demonstrate this in any way. An LCD clock typically draws such a low amount of power it is difficult to see how it would amount to more than a few cents per year. ---
**Author:** ![Arjuna34](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)\ **Post date:** [March 9, 2001, 4:40am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/5 "2001-03-09T04:40:59Z")
> [@](#): > > \*Originally posted by Ice Wolf \* > \*\*(the worst culprit, they said, was leaving the microwave on to tell the time. Said that uses more energy than the actual cooking). > ! \*\* Um, both the microwave clock and the display are still running while the microwave’s cooking, so it’s a little hard to see how the power would be less 🙂 BTW, the microwave at my work draws about 1780 watts when cooking, and 1 watt when idle … A nightlight draws about 10 watts, which at my low rate of 5.5 cents/kWh works out to 0.055\*(10/1000)_24_365 = $4.82/year (US). My WAG is that your music devices are drawing 10 watts, except for the Roland KC-500 amp. Since it’s a 160 watt amp, I’d WAG that it draws 20-30 watts of quiescent power. So, my guess is 50 watts max, maybe as low as 20 or 30. At my electric rates, this works out to somewhere between $10 and $25/year. If you specify the model numbers of keyboard and sound module, I could probably make some better guesses 🙂 ---
**Author:** ![bare](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bare/32/471_2.png) [@bare](https://boards.straightdope.com/u/bare)\ **Post date:** [March 9, 2001, 10:09am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/6 "2001-03-09T10:09:32Z")
Not to hijack the thread–but in the same vein, any one have figures on electric consumption with the typical computer set up we all have, monitor, box, speakers, printer, scanner when on but not in use? How about TV’s and VCR’s plugged in but not in use? ---
**Author:** ![Popup](https://avatars.discourse-cdn.com/v4/letter/p/94ad74/32.png) [@Popup](https://boards.straightdope.com/u/Popup)\ **Post date:** [March 9, 2001, 10:20am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/7 "2001-03-09T10:20:45Z")
[Energy 100](http://www.hr.doe.gov/energy100/world/70.html) > [@](#): > > Analysis suggests that the average U.S. house constantly leaks about 50 Watts, approximately 5% of the residential electricity use in the US. _I_ think those figures are a bit exagerated, but the site is sprinkled with references to DOE and is signed _Lawrence Berkeley National Laboratory_, so I guess one can’t just ignore them. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [March 9, 2001, 2:13pm UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/8 "2001-03-09T14:13:10Z")
> [@](#): > > \*Originally posted by tc \* > \*\*[Energy 100](http://www.hr.doe.gov/energy100/world/70.html) > > > [@](#): > > > > Analysis suggests that the average U.S. house constantly leaks about 50 Watts, approximately 5% of the residential electricity use in the US. > > _I_ think those figures are a bit exagerated, but the site is sprinkled with references to DOE and is signed > _Lawrence Berkeley National Laboratory_, so I guess one can’t just ignore them. \*\* Well, maybe not ignore, but question rather. I’m a “World Expert” on coal power plants, and I make mistakes all the time. Always politely question authority if something really doesn’t seem right after you’ve thought about it. However, in this case I would agree with their numbers _in general_. I have seen similar figures from our own energy audits - of about 2 to 3%. Perhaps they are accounting for appliances left on accidentally, or lights left on. Whereas our numbers were from “passive” use, including transformers. ---
**Author:** ![cornflakes](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@cornflakes](https://boards.straightdope.com/u/cornflakes)\ **Post date:** [March 9, 2001, 3:06pm UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/9 "2001-03-09T15:06:44Z")
At 150 Watts, the KC-500 almost certainly has a class B/AB output stage with two sets of power transistors handling the opposite sides of the output waveform. At rest, neither side is really working, so little to no current is being used. Even in use, this 150 Watt amp is rated to consume 125 Watts (150=125??? I know, but it does sound funny), which is as much power as two lightbulbs use. It’s not that big of a load. The keyboard and sound module probably have CMOS circuitry. CMOS transistors tend to use less power, for what that’s worth. In any case, they’re not made to produce power so they probably don’t consume much. If you want to get a rough idea of how much power the setup uses, shut the setup off and see whether the electric meter outside spins noticeably slower. I’ll bet that turning off a light will make a bigger difference. For a really rough guess, you could check for any hot spots on the cases. If the setup isn’t dissipating any energy as heat or sound, then it isn’t drawing any either. ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [March 9, 2001, 4:43pm UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/10 "2001-03-09T16:43:27Z")
Yeah, look at the electric meter… The reason for unplugging things is not only in electricity savings but to keep them from being zapped by power surges & to prolong life of an appliance. HD manf suggest one turn off the computer at night if its not needed. ---
**Author:** ![Briny\_Deep](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/briny_deep/32/17188_2.png) [@Briny\_Deep](https://boards.straightdope.com/u/Briny_Deep)\ **Post date:** [March 10, 2001, 1:24am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/11 "2001-03-10T01:24:13Z")
Thank you all for the responses! After reading them and the Energy 100 page, I’m now convinced it’s worth turning the stuff off. It adds up to pennies a year, no doubt, but that 5% figure surprises me enough to make me want to do something about it. Thanks! ---
**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\ **Post date:** [March 10, 2001, 2:17am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/12 "2001-03-10T02:17:12Z")
During California’s energy crisis, I read an article that estimated the total US energy leakage consumes the output of 6 or 7 power plants. Whether my cable box (Pioneer BA-6300) is on or off, it’s always the same temperature, rather warm. I’ve always wondered what in the cable box could need that much power when it’s off. It’s about as warm as my computer monitor case when it has warmed up (of course, the monitor draws much more power, and the case disperses the heat). ---
**Author:** ![panamajack](https://avatars.discourse-cdn.com/v4/letter/p/47e85d/32.png) [@panamajack](https://boards.straightdope.com/u/panamajack)\ **Post date:** [March 10, 2001, 2:19am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/13 "2001-03-10T02:19:38Z")
Someone around here clipped an article on this very subject, which mentions the studies done up at Berkeley, now expanded to office equipment. It appears to be from a publication ??? News (Science News?), vol. 159. They mention that their data is taken from the LBNL newsletter in an article by Jonathan G. Toomey & colleagues. It refers to the earlier result of 50W in homes (and reports this as being in SN: 10/25/97, p. 266), and on office equipment: > [@](#): > > According to the new estimates, such equipment wastes 71 terawatt hours per year nationally [this is US, of course] – or nearly 2 percent of the country’s electrical production. The figures given for office equipment leakage : computers & monitors : each 14.3 TWh copiers : 7.6 TWh laser printers : \>6 TWh Fax machines & inkjet printers : each 3 TWh Note that this is consumption in some cases by devices which are simply _plugged in_, not just turned on and not operating. For example, a computer monitor might use 5W at any time it’s plugged in. If you leave it plugged in all year, that’s about 40 kilowatt-hours a year. And if you live in California, that’ll be about an extra $200/year on your bill. If you really want to shut down your power consumption, use a switched power strip for these devices. But please don’t use the power strip switch to turn them off and on (turn the devices off, then turn the strip off). ---
**Author:** ![Arjuna34](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)\ **Post date:** [March 10, 2001, 2:25am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/14 "2001-03-10T02:25:51Z")
> [@](#): > > \*Originally posted by panamajack \* > \*\* > For example, a computer monitor might use 5W at any time it’s plugged in. If you leave it plugged in all year, that’s about 40 kilowatt-hours a year. And if you live in California, that’ll be about an extra $200/year on your bill. > \*\* That seems a _little_ steep to me, even for California. Here in Virginia, I pay $0.055/kHw, which would be $2/year for that 5W monitor. Is California really 100 times more expensive, at $5.50/kWh??? I’d have a $10,000 a month electric bill if I moved 🙂 Arjuna34 ---
**Author:** ![Arjuna34](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)\ **Post date:** [March 10, 2001, 3:45am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/15 "2001-03-10T03:45:47Z")
Here’s some power measurements from some items in my house: line voltage: 123 volts, 60Hz, 1.2% THD ```auto JVC VCR: off - 0.00A 0.0W 0.0VAR 0.0VA idle - 0.14A 8.7W 0.5VAR 17.2VA play - 0.20A 13.3W 1.6VAR 24.6VA RCA DSS receiver: off - 0.36A 25.8W 4.8VAR 45.0VA on - 0.37A 26.2W 4.9VAR 45.5VA JVC 31" TV: off - 0.00A 0.0W 0.0VAR 0.0VA on - 1.20A 77W 12.0VAR 140VA Teac 100 CD player: off - 0.00A 0.0W 0.0VAR 0.0VA idle - 0.00A 0.4W 0.4VAR 0.6VA play - 0.11A 11.0W 0.6VAR 13.6VA Sherwood 60W receiver: off - 0.00A 0.0W 0.0VAR 0.0VA idle - 0.37A 33W 13.3VAR 48VA HP DeskJet 882C printer off - 0.00A 0.0W 0.0VAR 0.0VA on - 0.00A 0.0W 0.0VAR 0.0VA printing - 0.22A 12.8W 4.1VAR 26.0VA ``` A = Amps, W = watts (real power), VAR = vars (reactive power), and VA = volt-amps (apparent power). It looks like a mixed bag- either “off” really is almost no power at all, or it’s almost full power. For this stuff it’s easy to tell- anything drawing 20 watts is going to get plenty warm. Arjuna34 ---
**Author:** ![beckwall](https://avatars.discourse-cdn.com/v4/letter/b/b487fb/32.png) [@beckwall](https://boards.straightdope.com/u/beckwall)\ **Post date:** [March 10, 2001, 3:49am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/16 "2001-03-10T03:49:16Z")
California power will cost you big time. I live in the desert and during the summer months, just about everyone here pays more for their electric bill than for their mortgage (for “average housing”). So we turn everything off, close the blinds and lay low for 3 months. When it’s really hot, we go to the movies for the “free” air conditioning. (sorry, off track here - carry on) ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [March 10, 2001, 4:09am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/17 "2001-03-10T04:09:25Z")
> [@](#): > > \*Originally posted by Arjuna34 \* > \*\* > > > [@](#): > > > > \*Originally posted by panamajack \* > > \*\* > > For example, a computer monitor might use 5W at any time it’s plugged in. If you leave it plugged in all year, that’s about 40 kilowatt-hours a year. And if you live in California, that’ll be about an extra $200/year on your bill. > > \*\* > > That seems a _little_ steep to me, even for California. Here in Virginia, I pay $0.055/kHw, which would be $2/year for that 5W monitor. Is California really 100 times more expensive, at $5.50/kWh??? I’d have a $10,000 a month electric bill if I moved :)Arjuna34 \*\* I agree - I think there was just a _slight_ math error in there… ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [March 10, 2001, 4:12am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/18 "2001-03-10T04:12:27Z")
> [@](#): > > \*Originally posted by zgystardst \* > \*\*During California’s energy crisis, I read an article that estimated the total US energy leakage consumes the output of 6 or 7 power plants. \*\* Just an obvious note, perhaps. But I do hate it when I read articles (especially in USA Today) that will say things like “as much energy as X power plants”. Considering that a “power plant”, depending on how it is defined, can be anywhere from 100 kW to 4,000,000 kW, it is not a good measure of energy consumption at all. ---
**Author:** ![panamajack](https://avatars.discourse-cdn.com/v4/letter/p/47e85d/32.png) [@panamajack](https://boards.straightdope.com/u/panamajack)\ **Post date:** [March 10, 2001, 6:36am UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/19 "2001-03-10T06:36:20Z")
Okay, the $200 figure was meant as a joke … actually, electricity prices are still regulated to consumers in California, so the prices are in line with the rest of the US (a few dollars a year for a 5W leakage appliance). (news reports say the Federal government might order the power plant owners to refund money to the utilities out here … meanwhile the state’s busy signing contracts and trying to keep it secret. I believe rumors say they’re paying $65/MWh) ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [March 10, 2001, 4:13pm UTC](https://boards.straightdope.com/t/energy-cost-of-idling-electronics/57302/20 "2001-03-10T16:13:12Z")
Im in California & the gov is paying $44M a day for elec, so our rates for elec are pretty low, 9.9kw. Natural gas, however is three times what it was in 2000. It dropped a little this month. Anyway, the idea is not just about saving a few bucks a year but prolonging life of an appliances.