Standby Power For TV And Net Devices In Perspective - Page 1
Forum section: electronics / general

author: SgtRock
author_rank: Unknown
timestamp: July 01, 2012, 03:56:18 am
content: Greetings EEVBees:--See below a great article about actual standby power demand of devices. Wall Warts are not addressed in the article. If you have an accurate idea of what is using how much of your electricity, you will have a better idea where to start economizing, eh?http://www.theregister.co.uk/2012/06/29/energy_saving_trust_report/--Lighting and personal comfort, are also in play."The paragraph quoted above refers to ceiling lights powered from 5A lighting circuits, not ones plugged into the wall: but these often use transformers too - for instance for low-voltage ceiling spotlights. In such cases, of course, it is often not feasible to cut power to the transformer without knocking off a breaker or pulling out the light fitting. It's odd that the very people so keen to unplug the telly are often big fans of such spotlights, and would never believe that they waste far more juice even when switched "off" than the TV does on standby.""The big stuff is travel, making and having things (ie buildings, furniture, tools, interior decor, infrastructure etc) and heating/cooling (a large amount of this is laundry and personal hygiene). Remember: skipping one bath or shower saves as much energy as switching off a typical gadget at the wall for a year.""I'll have the Alfalfa sandwich, and the smashed yeast"Woody Allen 1935 -Best RegardsClear Ether

author: Rerouter
author_rank: Super Contributor
timestamp: July 01, 2012, 05:46:19 am
content: yeah i tend to just laugh at the tv "energy wise savings" bull where they first thing they reccomend is unplug your tv at standby, primarily due to the people so obsessed about saving those cents per year usually buy the cheaper tv's which dont like being hit with inrush current 2-3 times a day,and spot on about the low voltage lighting and wall wart lamps, it annoys me to no end, as i have a neighbour obsessed about unplugging his tv, and his standby on the lights is 18W!

author: vk6zgo
author_rank: Super Contributor
timestamp: July 01, 2012, 08:03:49 am
content: Down light "transformers" are normally disconnected from the mains supply when in the" Off" condition.I have never seen any which aren't controlled by a normal light switch on the wall,& in some cases, a dimmer.If the dimmer is turned right down,they will be dark,but that is not "Off"!"Off" is with the wall switch turned "Off".OK,they are very wasteful of power when they are "On".& maybe when dimmed,but "Off"-------I'm sorry,but I'm going to have to call "bullshit" on that one!The IKEA lamp that was initially referred to may well have a switch after the "transformer",but to extend that to a totally different type of lighting system is stretching things to breaking point!If you have a Solar HWS,the "miss a shower" story doesn't hold up either!The biggest problem with these disputes is that both sides feel quite free to make up stuff that supports their argument!

author: johnwa
author_rank: Frequent Contributor
timestamp: July 01, 2012, 08:29:27 am
content: I think the same comments apply for standby power as for CFLs. Used appropriately they make sense, but the debate seems to divide into two camps: the "if you are using any incandescents at all you are killing baby seals" brigade, and the "its all a government plot to take away our light globes and give us mercury poisoning" lot.In most households, it should be possible to achieve a meaningful reduction in energy usage by switching things at the wall. Though it is stupid to blindly unplug every last appliance - for all the trouble rummaging around behind the TV, you might only save 0.5W on standby. I think it is better to at least measure the standby consumption of everything, and then find where the most gains can be made, with the least inconvenience, in terms of switch accessibility/frequency of switching/loss of clock settings, etc.I went over everything in the house a while ago, and now there are a few things that I switch off at the wall. The microwave oven uses 6 watts, I didn't use the clock on it, and the wall switch is easily accessible, so it makes sense to switch it off. Likewise for a couple of computers that are only used occasionally. However, I leave the stereo plugged in, so I can switch it with the remote control.You are right of course, SgtRock, heating is responsible for the largest proportion of energy usage by far, and if you are going to spend money in an effort to improve efficiency, this is the place to do it.

author: G7PSK
author_rank: Super Contributor
timestamp: July 01, 2012, 09:14:40 am
content: The campaign to switch of TV's when not in use in order to save standby current is more about the total power saved by the nation as a whole rather than a few pennies saved by the individual. 18 watts times fifty million or so is a large chunk of output from a power station, the same is the reason that the EU has banned the manufacture and sale of traditional light bulbs, A huge amount of generation capacity is relived so that it can be taken up by all the cell phone chargers that get left on, A friend of mine just decorated their spare bed room that had last been used about 7 years ago plugged into a socket under the bed was a phone charger that was still warm, how much power is that wasted?

author: SeanB
author_rank: Super Contributor
timestamp: July 01, 2012, 10:24:17 am
content: That again is due to the owner. The standby power use that is claimed to be the output of a power station is bogus, as at best it will be the output of the smallest unit in the smallest station. It might be a difference if you are running the grid at close to collapse with no reserve margin, and in that case you are in deep doodo if an incident like a bird shorting out a power line happens, as the cascade will definitely island the system into a total blackout, and it will take a day or more to restore a minimal grid then. That is a political problem, as it means that no reserve is left and there is absolutely no more redundancy to handle anticipatable faults.It would be far better to go for solutions like insulation, fixing street lighting that is faulty and dayburning ( 400W by 20 poles per kilometer adds up rather quickly to a signifigant load) and promoting solar heating of water ( the solar heating is big here in SA, with a sponsorship of low cost homes by the utility, paid by the few who pay through the nose for power, which is making a bigger difference than unplugging a 1W load per household) and using gas for cooking and heating. All big loads that are able to be shifted to an alternative, the lighting of a house is the least effective thing to do, it just makes the people feel that they are doing something.Sad is that i have been doing this for the last 20 years, and the least effective was cutting small load usage. The biggest was insulating the geyser, the first 2m of pipe out of it and using the stove less and using gas occasionally.I will give a tip that saves a lot of power - when washing clothes take them out immediately the machine stops, fold them neatly ( still damp) and wrinkle free and then hang them up to dry in the shape they hang naturally. they will dry wrinkle free, and will either not need or will need less ironing. Ironing clothes, or using a drier, is a massive energy waste that is easily avoided by this. If ironing a shirt for use under a jacket you only need to do the collar and the top of the front, as well as the ends of the sleeves. The rest is hidden anyway.

author: mariush
author_rank: Super Contributor
timestamp: July 01, 2012, 11:56:26 am
content: The best thing anyone could do is to get a Kill-a-watt device (or something similar) for themselves, to see how much each thing eats from the wall.I got one off eBay and it works great.What I found is that I have two monitors on the desk, both consume about 25-40w in total when running, less than a watt when computer is off.The Nokia charger I leave in the socket uses about 0.4w unplugged to anything.The computer power supply also uses less than a watt when idle (seasonic gold efficiency)However, the Logitech 5.1 speakers consume as little as 15-20w at low volume, and about 45 watts at about 60% volume. Even when the computer is off, it will suck about 15 watts from the wall due to the old amplifier chips it uses.I didn't check lately but I'm sure the cable modem uses about 5 watts constantly and it's always on. The cable decoder set top box is also sure to use about 10-15 watts but didn't test it.So for me at least, it's pointless to worry about a phone charger or something drawing power when off, when I could accidentally forget the speakers on over night and they'll waste as much power in a few hours as those devices drain within a month.

author: SgtRock
author_rank: Unknown
timestamp: July 01, 2012, 01:50:23 pm
content: Dear G7PSK:--I have read with pleasure, many of your posts. As a general matter you obviously have forgotten more about many areas of Electronics, than I know. That is why I am so surprised at your reaction to, what I regard as a rather forthright and well reasoned article, the thrust of which is that, the savings of unplugging have been overstated by a factor of between 5 and 10 times. The figure you use is 18 Watts, which is only about 28% of the 64 Watt average the Energy Savings Trust reports, don't you trust them?You stated:"The campaign to switch  TV's when not in use in order to save standby current is more about the total power saved by the nation as a whole rather than a few pennies saved by the individual. 18 watts times fifty million or so is a large chunk of output from a power station..."--Let me see if I have this right. What you are saying is that there is one of those multiplication deals going on. So that if 50 million people plugged and unplugged every possible standby using device, multiple times a day they would pert near like to plum save the output of an entire gereratin station. Of course this ignores the possibility that they would burn up a few extra millions of devices due to as many as a thousand extra instances of in-rush current per device. The cost of replacing these devices might be more than the power saved.--With regard to your statement that down lights do not use standby power, is it your position that both the author of the article, who specifically mentioned 5A lighting circuits, and Rerouter who mentioned the 18W standby of his neighbor's lights, were both throwing the bull, so to speak? You might want to consider that merely because you have never seen something, it is not absolute proof that it does not exist.--Certainly you are correct though that if you do not use electricity to heat water, you only save water by not taking a shower, because you have already saved the electricity by using one of the only known non-scam solar schemes. But I think most of us understand this sort of thing without explanation.--You stated:"A friend of mine just decorated their spare bed room that had last been used about 7 years ago plugged into a socket  under the bed was a phone charger that was still warm, how much power is  that wasted?"--Good point, I am also given to understand that Camellia Sinensis futures have been taking a beating of late on the Shanghai Exchange.--Lastly, you mentioned the CFL Totalitarian Juggernaut. I just ordered some small mercury tilt switches from Hong Kong. I am making a warning light from the tilt switch and a flashing LED for a dog collar (total cost less that $4), to remind me to shut a ball valve going to a leaky shower valve, a stop gap until a scheduled re-plumb of the whole house is carried out in a few months. But I digress. If a child were to take one of these mercury switches to school, and if it should fall and break, the building would be evacuated and the Hazmat Team in Bunny Suits would be called. But if a CFL were to break, they would merely sweep it up and go on about the business of under-educating the kids. As near as I can tell, this is because, the mercury used in CFLs is magic and has no toxic properties.--Of course, if you read my original post, you will see that my point was not to tell people what to plug or unplug, but to help them get a realistic idea of the things they can do to save electricity before reaching the rather arduous need to unplug as many as 5 or 10 devices, possibly 3 or 4 times a day, 365 days a year."How could Nixon have won? I don't know a single person who voted for him!"Pauline Kael 1919 - 2001Best RegardsClear Ether

author: G7PSK
author_rank: Super Contributor
timestamp: July 01, 2012, 02:36:07 pm
content: Dear Sgt Rock The advertising campaign here in the UK to turn of and save power is most certainly more about the total power saved by the nation than anything else, I don't think I mentioned water heaters or down lights.We have a situation developing in the UK and the rest of Europe where we are running out of generating capacity as old plants end their usefully life span and new plants are not being built as the generating company's have been privatetised, the share holders want instant returns on their investment not something 20 years down the road, and who can blame them.There is also gross under investment by the utilities in the UK as they struggle to raise further investment.That is why some things are better run by state organisations or quangos as we call them in the UK,who can take the social investment aspect into consideration and dont need an instant return on monies invested but can look at 25 or 50 years on projects, you would not expect roads to be run by private company's for the social good of the community and in the same way other infrastructure utilities also are best run centrally for the good of the nation.P.S. I know bugger all about electronics compared to many on the forum But I do know a bit about power generation as I have been involved in building power generators for the pas 40 years or so.

author: Rufus
author_rank: Super Contributor
timestamp: July 01, 2012, 03:06:49 pm
content: Quote from: G7PSK on July 01, 2012, 09:14:40 amTotally stupid argument. An insignificant 0.1% of power used for standby in one household remains and insignificant 0.1% of power used by millions of households.Anyone who thinks multiplying a small proportion by a big number makes the proportion bigger is arithmetically challenged.Quote from: G7PSK on July 01, 2012, 09:14:40 amAbout 1W and I would have to work for about 170ms a day to pay for it.

author: tom66
author_rank: Super Contributor
timestamp: July 01, 2012, 06:48:37 pm
content: Let's do a sample calculation on inrushTake a simple 230VAC to 5VDC, 300mA adapter (BlackBerry charger, for example.)Typical mains cap in this is going to be ~10µF. At 325V peak this is 0.52 joules. (1/2 CV^2) Divide by 3600 to get watt hours. This is 0.14 milli-watthours.Compared to typical standby power of 0.05W - 50mW - you will use more mWh in just 10.1 seconds.So, unplugging and plugging in chargers for any less than 10.1 seconds wastes energy. Any more is probably completely fine.Just like the debate on whether or not turning off fluorescent tube lighting with normal capacitance starters saves energy. It does, but you must turn the light off for at least 15 seconds for it to matter.

author: Rufus
author_rank: Super Contributor
timestamp: July 01, 2012, 07:15:37 pm
content: Quote from: wilfred on July 01, 2012, 03:23:26 pmNot arguing about proportions is the problem.Quote from: wilfred on July 01, 2012, 03:23:26 pmWhich is the completely wrong and stupid argument.If expending X amount of effort or money to achieve a saving Y isn't worthwhile multiplying X and Y by a million changes nothing, it is still not worthwhile. The argument made by arithmetically challenged idiots is a million Y is worthwhile compared to a single X.Quote from: tom66 on July 01, 2012, 06:48:37 pmInrush energy is irrelevant the problem turning things on and off repeatedly is wear and tear on the switch and stress on components causing earlier failure followed by the cost of lack of availability and repair or replacement.The cost of an electrician call out to replace a wall socket with a knackered switch would provide 1W of standby power to a device for about 50 years.

author: G7PSK
author_rank: Super Contributor
timestamp: July 01, 2012, 08:40:15 pm
content: What I am saying is that the drive to switch of or unplug TV's etc is politically driven to reduce the overall draw on power stations. Whether the amount saved is worth while to an individual I do not know but there is a political push for power saving due to things like carbon credits and to a far greater extent the looming shortfall in generating capacity with old coal and nuclear plants going off stream and nothing really coming along to replace them (at least in Europe) other than a few gas fired dual cycle plants. And with north sea gas running low there is an increased dependency on Russian gas the supply of which is politically tenuous to say the least. There are of course the wind farms (you cant look out along the Norfolk coastline now without seeing at least one wind farm and often several, but the wind does not blow all the time in fact most times I have seen the wind farms they are idle.so the politicians fix is to turn of the TV and with a bit of luck you will be to idle to turn it back on to see the report on the latest politician to be caught with his pants down or hand in the till.

author: IanB
author_rank: Super Contributor
timestamp: July 01, 2012, 09:19:30 pm
content: Quote from: G7PSK on July 01, 2012, 08:40:15 pmFair enough, but what others are saying in response is that a reduction of 0.1% for individuals will never amount to more than a 0.1% reduction in the overall load on power stations. Much less in fact, due to other industrial and commercial electricity consumers. It isn't a bad idea to reduce consumption anywhere it is reasonable, but it isn't going to save the world.

author: G7PSK
author_rank: Super Contributor
timestamp: July 01, 2012, 09:35:56 pm
content: Politicians are not known for their maths skills or common sense,I see full well what the others are saying and don't disagree with them but as Tesco say every little helps.

author: vk6zgo
author_rank: Super Contributor
timestamp: July 02, 2012, 09:23:23 am
content: Quote from: SgtRock on July 01, 2012, 01:50:23 pmSarge,I agree that the argument for turning everything off at the wall to save "standby power usage" is at least,extremely suspect,but I disagree with countering that argument with one that has similar defects.Cheers,VK6ZGO

author: tom66
author_rank: Super Contributor
timestamp: July 02, 2012, 09:37:31 am
content: Mechanical wear for switches and plugs isn't a big issue. Look at a relay for a good example: 5,000,000 mechanical operations expected.http://www.farnell.com/datasheets/1537833.pdf

author: T4P
author_rank: Super Contributor
timestamp: July 02, 2012, 10:25:17 am
content: Relays arerelaysthey hardly got much weight to shiftHow about the cheapies?The cheapies ain't hardly got that much life, probably more like 1,000,000 mechanical operationsFor electrical performance they start off at 100,000 but drop that to 10,000 at rated current and at 250VFor plugs they have a shitload of force to handle, especially the OHL ones that require a lot of force to lock contactBundle that with poor quality and BAM probably around 100 cyclesIn this OHLJ filled world it's always better to err on the side of understimation

author: Unknown
author_rank: Unknown
timestamp: July 02, 2012, 11:25:47 am
content: Quote from: vk6zgo on July 01, 2012, 08:03:49 amFor fixed wiring you are quite correct the mains is interupted by a wall switch. Plug in appliances that is another story! Much of the junk our supposedly energy saving governments allows to be imported uses secondary switch and leaves a Wunhunglo transformer primary permanently across the mains. Mis information abounds, ask any politician and they'll bank on about carbon, and energy saving lamps and all sorts of plain wrong crap.For a clever country it has me **sed why people voted for the current lot of numbies! Or why the public preferred face of the other side is the minister most responsible for not saving the planet by quadrupling the cost of light globes. Idiots all!

author: vk6zgo
author_rank: Super Contributor
timestamp: July 02, 2012, 04:23:09 pm
content: Quote from: Uncle Vernon on July 02, 2012, 11:25:47 amThe story so far-------In the article Sarge referred to,they made the original point re plug in lamps from IKEA,then extended that to down lights alleging that they were left in "standby", using large amounts of power.Rerouter made a comment re his neighbours alleged power draw of 18 watts for downlights in "standby".I,rather intemperately,used the "male bovine excreta word",in refuting these suggestions.I have always assumed any draw from real transformers which are not loaded to be minimal,but I have never done any tests."Pretend" transformers such as those which are commonly used today,may be different.Re: The Pollies---- The thing is,they are all lay persons,with no real knowledge of Technology,Looking at their education,their Degrees are in Law,Economics,Political Science,Social Science,etc,which fits them well for quite a few of their responsibilities,but whenever they come up against Science & Technology,they know about as much as the young person at Mac Donalds who serves burgers.So they cast around to take advice from experts----& there are plenty of them,all with their own cart to push!Back in the day,such pollies were balanced a bit by practical people,such as farmers in the old Country Party,& trades people in the Labor Party.I bet we'll never again have an ex Engine Driver as Prime Minister!Who you vote for is a lot like what football team you barrack for!Being a Labor voter is a bit like being a Fitzroy supporter----They haven't quite changed their name & moved to Brisbane,but they've changed bloody near everything else!On another occasion,I suggested the answer to energy problems would to be to attach alternators to Ben Chifley's & Bob Menzies' remains to generate power as they turn over in their graves at what their successors have done to their Political Parties!

author: Unknown
author_rank: Unknown
timestamp: July 03, 2012, 12:31:12 am
content: Quote from: vk6zgo on July 02, 2012, 04:23:09 pmI'd substitute the term garbage for your term pretend. Current draw is certainly a lot less than with the secondary loaded but unlikely to comply with the <1W aim we are supposedly all chasing. No doubt garbage switch modes will soon replace the transformers, albeit driven by lowest cost rather than any energy concern. The point remains however that these are just bad design with dubious safety considerations in their design.What irks me is the madness that has the clueless masses playing energy sleuth while the government decides all manner expensive of nonsense of no consequence other than political and economic ones. This garbage should never be allowed to be imported let alone sold yet it remains illegal for a qualified EE to replace his own light switch. Who votes for these morons?Changing the nations light globes resulted in exactly what % of savings on the national and household power bill. Yeah that was a good one, can see why that jackass is the labor voters favorite liberal.On sunday refrigerant went up by 300% across the board. For what? Australian manufacturers have to cop the full whack and try to remain competitive. Yet you'll be able to by a pre-charged POS imported A/C or fridge from Raj Mfg Co that wont cop any of that tax. That'll save the planet and some non specified grandchildren how exactly? Same applies with your motor car, 300% impost on the A/C of anything locally assembled or manufactured, while a late model Kia Kevorkian will sail through unchecked. The consider the cost of an A/C re-gas for any car, that's just gone up $500 to $1K. For what, to allow some lying troll cling onto a few more months at the helm of a coalition of nutjob lefties?Call me a denier, I think that is standard leftie practice but there is bugger all science to any of this. More importantly it's achieving nothing but to cripple industry on this side of the ditch. Sure you leftie dreamers are doing something to ensure the future of grandchildren unfortunately none of them being Australian grandchildren.Eliminating "unnecessary" standby and in-use current is something we should always be striving for, but not at the expense of common sense. The carbon pollution created by a whole suburb or well designed LED TVs on standby remains inconsequential in comparison to that used by a red headed troll flying halfway across the planet in a old jet aircraft for the purpose of banging on and insulting foreigners. What happen to the Kevin07 fleet of ministerial Prius fleet, didn't take these grubs long to slip back into V8 holdens, how much planet was saved there.Quote from: vk6zgo on July 02, 2012, 04:23:09 pmI'd imagined a useful amount of energy could be created from the heat of burning the current lot at the stake.!The only problem being being no one can be sure how much carbon tax would apply to the burning of red hair.

author: vk6zgo
author_rank: Super Contributor
timestamp: July 03, 2012, 01:22:03 am
content: Quote from: Uncle Vernon on July 03, 2012, 12:31:12 amOr,as Tony is fairly physically fit,we could put him in a squirrel cage!-----far more sustainable.

author: WorldPowerLabs
author_rank: Regular Contributor
timestamp: July 03, 2012, 02:37:57 pm
content: Quote from: tom66 on July 02, 2012, 09:37:31 amI'm not trying to start a disagreement, but (in the USA) we have many devices with very cheap, poor quality plugs. I've seen the blades on plugs get chewed up quite badly just from plugging and unplugging a few dozen times (not under load -- no arcing, just mechanical wear).I do unplug almost everything I'm not actively using. Not for power savings, but for safety. This way, I won't accidentally leave a toaster oven or heater plugged in and I don't have to worry about onehunglow components releasing their magic smoke when I'm not home.