'Smart' power strip - scam? - Page 1
Forum section: electronics / general

author: Poe
author_rank: Frequent Contributor
timestamp: October 02, 2012, 09:09:11 pm
content: So my electricity supplier sent me anenergy conservationpackage. It contained some LED nightlights, CFLs, new water aerators, a low volume shower head and the most expensive bit.. a 'smart' power strip.The power strip had six outlets. One 'master outlet' for your desktop computer and four other 'slave outlets' for support electronics like display, audio system, printer, scanner, etc.The idea is that when the your computer is off, the strip automatically turns off slave devices to conserve phantom energy draw.My question... Does the math work? What's the ROI? Don't most devices consume so little power while inactive that it's in the noise of your home's overall consumption?This power strip appears to consume one watt by itself when the master is active. Roughly half a watt when inactive. I would love some numbers because it looks like the master device's duty cycle is really important. That additional one watt of stand-by power consumption might offset any inactive savings.I can see it really helping when used on something like an entertainment center if a high power draw device was plugged into a slave outlet (i.e. plasma). Although I was under the impression that the reason these devices consume so much power in stand-by mode was to reduce the turn on time. ?Meh. Just typing out loud. What do you think?

author: oPossum
author_rank: Super Contributor
timestamp: October 02, 2012, 09:19:22 pm
content: How would it know the difference between a TV that draws 10 watts when off, and a cell phone charger that draws 10 watts when operating?

author: Jeff1946
author_rank: Regular Contributor
timestamp: October 02, 2012, 09:38:14 pm
content: More or less a wash. Most "Energy Star" stuff in the US consumes less than a watt in standby. Assuming you have a printer and a monitor plugged in the strip should be little difference. If you have other stuff like power for speakers which is usually wall wart then it would help. Assume you dont want to plug your router/wifi in as it may talk to other computers when yours if off.

author: Balaur
author_rank: Unknown
timestamp: October 02, 2012, 09:51:34 pm
content: I've made something like that by myself many years ago. I just wanted to power up the subwoofer automatically whenever the amplifier was on. It was more for convenience than else.Nowadays, it also provides power to a Bluetooth A2P module and a TV set-up box.I'm happy with the set-up and the math checks up. The controller by itself draws a little less than 1 Watt most of the time.In all, accounting for an usage factor of let's say 4 hours on/day is much better than leaving the subwoofer (~20W when no sound) and the set-up box (~15W) always on. BTW, my set-up box is a smart one with a hard disk and so on. It's also always on, the power off only turns off the display and TV out.Yes, I'm fully aware that there is such a thing as a power strip with a manual On/Off switchCheers,Dan

author: Matje
author_rank: Regular Contributor
timestamp: October 02, 2012, 10:03:01 pm
content: Quote from: Balaur on October 02, 2012, 09:51:34 pmWhich incidentally makes it usually way more robust in the face of transients, spikes and stuff, when switched off of course. I wouldn't trust the "smart" electronics too much, it's after all manufactured to a low, low price.In other words, this smart stuff is not necessarily a scam, just not that good an idea in the long run, at least if you pay for it yourself. It may even be dangerous for the connected devices.

author: GeoffS
author_rank: Unknown
timestamp: October 03, 2012, 12:42:22 am
content: If you have an electric stove or electric hot water, then the power used by your electronic devices pales into insignificance.I findthese remote control power outletsmuch more useful. It's not automatic but it is convenient.

author: Pentium100
author_rank: Frequent Contributor
timestamp: October 03, 2012, 03:30:19 am
content: My amp has two switched outlets (they get the power when I turn on the amp), but the power is limited to IIRC 100W or so, it is convenient though, I turn on the amp and other devices turn on (the amp itself has a mechanical switch). If I decide to use this for all of the devices in that room, I think I will just buy a couple of relays (with 220VAC coil voltage) and be able to turn on everything just by turning on the amp.

author: tom66
author_rank: Super Contributor
timestamp: October 03, 2012, 11:14:37 am
content: New legislation states that devices without any interactive feature in standby (for example, a clock, timer, automatic recording) may not use any more than 1W in standby mode.So, I mean, worst case, your widgets use 3W in total, that's 0.39p/hr... if the strip costs £20 (guesstimate), you recover the cost in 51,282 hours... or about 5.8 years. That's ignoring the fact that itself it eats up probably ~1W to do its control function.

author: EEVblog
author_rank: Unknown
timestamp: October 03, 2012, 11:25:04 am
content: Quote from: Poe on October 02, 2012, 09:09:11 pmEven with say 5 devices connected at a (low) 1W each, that's 5W.@ say 25c/kWh, that's 1.25 millcents(!)/h, or 3c/day, or $11/year (assuming it's always left off, real figure would be less based on usage)So that's an absolute rock bottom figure based on you having well designed "green" products with low standby power.Many devices aren't that low, and can easily consume 5-10W when off.Dave.

author: EEVblog
author_rank: Unknown
timestamp: October 03, 2012, 11:35:33 am
content: Quote from: GeoffS on October 03, 2012, 12:42:22 amI'm using those in the lab for the new LED lights. Only need them switched on when I'm shooting video.Very handy. They default to off when I come in and switch the main lab lights lights off, and of course switch off when I walk out and turn off the lights.Dave.

author: saturation
author_rank: Super Contributor
timestamp: October 03, 2012, 12:04:55 pm
content: A real issue with phantom is more the aggregate population than the cost to you. Consider if you have 5 devices each drawing the Energy Star 0.5W each, = 2.5W. Over a year, 8800 hours ~ 22,000W/hr. In the USA, ~15c/kWh ~ $3.30 one spends for this energy doing nothing. However, multiply that by everyone else in your city, and you get an idea of wasted power the city has to provide.I use the X10 lamp modules since the 1990s, but my watt meter can't measure less than 1W so not sure it draws far less than Energy Star. Unplugging them is the best option to reduce 0.5W draw or using a old style master switch that kills power to the whole setup when unused. Those old under-monitor power centers are making a come back for this type of function.http://www.amazon.com/Tripp-Lite-TMC-6-6-Outlet-Protector/dp/B0000AKA90/ref=sr_1_1?ie=UTF8&qid=1349265633&sr=8-1&keywords=power+centerWhen those centers fell out of favor 10 years ago, they couldn't give them away, they were like $1-5 each. Now its $30.http://www.x10.com/promotions/sh624_automation_pack.html?EM

author: ejeffrey
author_rank: Super Contributor
timestamp: October 03, 2012, 03:30:54 pm
content: If all of your devices are on standby, the smart power strip only saves you a few bucks a year, but plenty of devices either have no standby mode, don't enter it automatically, or still consume a fair bit of power in standby mode. Laser printers, audio amplifiers, and CRT monitors are notoriously bad, but plenty of other devices consume plenty of standby power. If you have no need of them when your computer is off, then a smart power strip is a great way to turn them all off at once. Back in the Good Old Days, we just turned our computers on and off with a regular power strip, but with ATX power supplies and their soft power buttons, that isn't as convenient.

author: SeanB
author_rank: Super Contributor
timestamp: October 03, 2012, 03:31:55 pm
content: More signifigant is lights that are burning 24/7/365 on roads. One 400W lamp will negate the effort of 200 houses saving standby power. how many do you see every day, if you notice them at all.

author: ejeffrey
author_rank: Super Contributor
timestamp: October 03, 2012, 03:51:57 pm
content: I don't see how that is relevant here. The excuse that "other people waste more power than me" is not a reason to avoid wasting power, and the simple fact is that a few $ for a smart switch that saves a few watts of power will pay for itself in a year.I also think your math and your logic are pretty crazy, but that is another story. An average household in the US (no idea about s. africa) has more than 2 watts of standby power. 400 watt lamps are rather uncommon, at least in residential settings. Industrial and commercial environments also consume plenty of power, but they are way ahead of residential use in fixing the easy forms of waste, especially when it comes to lighting. Even if your examples were reasonable, the premise is not. The lamp only 'negates' other energy settings if it is an alternative. Powering off unused appliances does not increase the number of 400 watt lamps burning!

author: Tepe
author_rank: Frequent Contributor
timestamp: October 03, 2012, 03:56:51 pm
content: Quote from: saturation on October 03, 2012, 12:04:55 pmThat is a bit a strawman. Everybody wasting some fraction of a percent of the electrical energy they buy does not add up to a huge percentage of the energy supplied by the power plants to the consumers being wasted. It remains a small fraction of the total. Thinking otherwise is politicians logic. :-)

author: SeanB
author_rank: Super Contributor
timestamp: October 03, 2012, 04:23:15 pm
content: Streetlamps are 400W on busy roads and freeways, 250W on main roads and 175/125/80W on side streets. Under each fitting is a label giving the wattage in 10's of watts. standby power in the USA can be big, with all the appliances in a typical house.Here the most common standby power users that cannot be switched off are water heaters ( often with a timer to reduce the demand though), electric gates, fences and security systems ( not likely ever to be turned off) then domestic refrigeration, and finally home entertainment. This is in order of power use. Thus saving 50% of the power used by the lowest users does very little, the biggest changes are to insulate water heaters, energy efficient fridges and to cook more efficiently so as to lower cooking element on time. I have done all 3, and am probably still using half the power of a comparable household ( similar size, number of occupants and lifestyle) who unplug the cell charger and think they are doing something "Green" while having the aircon on max chill, but leaving the window open to get the breeze.

author: saturation
author_rank: Super Contributor
timestamp: October 03, 2012, 07:30:45 pm
content: In the end you want a complete system, not simply just power strips for wall warts. Its more that just a political process. The standby power issue reached the point of law in some countries, and is generally called the 1 watt initiative:http://en.wikipedia.org/wiki/One_watt_initiative... which is just a part of a whole system to reduce 'waste' that is, increasing efficiency, called:http://www.energystar.gov/index.cfm?c=products.pr_where_moneyin the USA but is now a worldwide initiative:http://en.wikipedia.org/wiki/Energy_starInitiated such a system on my home several years ago, adding mechanical switches to wall warts, replacing rather than repairing power consuming appliances, switching to CFL and LED lighting, and using Energy Star power guidelines, reduced my electric billsover60%. 90% of my current bills today come from one device: water heater, even with a timer switch. It has zero impact on my lifestyle comfort and all changes are now user transparent.So, the while the program initially appeared as a green initiative, it can have immediate economic value. Not only have my maintenance costs dropped, but I use the HVAC system now more frequently, and still save.There are 2 caveats, installing new devices properly and insuring reliable models otherwise, adding repair costs on new devices eats into your budget, and cancels the economic benefits.Quote from: Tepe on October 03, 2012, 03:56:51 pm

author: LaurenceW
author_rank: Frequent Contributor
timestamp: October 03, 2012, 10:24:31 pm
content: ORYou could just throw away that old inefficient 'fridge in the garage (it's only got beer in, anyway), and get a modern efficient one.Or you could take one less car journey, a week.I watched a good TV program about the Mars "Curiosity" mission, last week. It made me LAUGH OUT LOUD to see the rational, intelligent engineer drive to work in his Prius, only to light a MASSIVE firework of a space rocket which probably consumed MILLIONS of times more energy than his car "saved", just to put a robot on a distant planning. Clever, but dumb.I too was building my own "intelligent" power strips years back, simply because I was too lazy to switch everything off, when I left my lab. They must help, but don't fall into the trap of thinking that's enough.The press like to jump on "energy saving initiatives" and each one reveals their horrendous, nay scary (since these people still set opinions of the masses) ignorance. The simple secret is to USE LESS STUFF, but in a society predicted on more, not less, consumption, that message just gets drowned out.What are we to tell our grandchildren?Where was I?

author: Pentium100
author_rank: Frequent Contributor
timestamp: October 03, 2012, 11:35:04 pm
content: Quote from: LaurenceW on October 03, 2012, 10:24:31 pmThey help in a sense that you then turn the devices off instead of leaving them in stand by since it may be inconvenient to turn them off normally (the outlet is hard to reach etc). A Hi-Fi system is one example - there are many devices, most of them probably use soft power buttons. Even using an extension cord with a switch would mean that I have to use one more switch. This is why better amps have switched outlets - I am not going to use my record player with the amp off anyway and when I turn on the amp the record player also turns on (the particular model I have has a low voltage power switch - the transformer is always on, the switch just switches the low voltage side).As for the energy conservation - I do not really care - my computers use at least 800W and they run 24/7, o the 20W or so of stand by power does not really matter. On the other hand, if I only use the device occasionally, switching it off may prolong the life of its power supply.In my opinion all devices should have mechanical switches, like TVs do - you can leave it switched on if you want to keep the device in standby, but if you ant to switch it completely off you do not have to pull the plug.

author: Monkeh
author_rank: Super Contributor
timestamp: October 03, 2012, 11:40:37 pm
content: Quote from: Pentium100 on October 03, 2012, 11:35:04 pmNot all TVs have switches.Here in the UK, though, we have this genius concept of putting switches on sockets!

author: Pentium100
author_rank: Frequent Contributor
timestamp: October 04, 2012, 01:20:41 am
content: Quote from: Monkeh on October 03, 2012, 11:40:37 pmAll the TVs in my house have them, so I thought that most if not all of them had the mechanical switches - at least all the CRT ones.QuoteWhich is just marginally better than having to pull the plug. If the socket is behind the cabinet with the TV and other equipment then the switch there is not that useful. Switch on the front panel of the device would be much better.

author: Monkeh
author_rank: Super Contributor
timestamp: October 04, 2012, 01:42:46 am
content: Quote from: Pentium100 on October 04, 2012, 01:20:41 amCRTs, yes. CRTs are long gone.QuoteAnd your excuse for not having accessible isolation is?

author: Pentium100
author_rank: Frequent Contributor
timestamp: October 04, 2012, 07:44:17 am
content: Quote from: Monkeh on October 04, 2012, 01:42:46 amOK, so one more point to add to the list why CRT TVs were better.Why the change then? I mean the switch is not that big to require a case made for a CRT.QuoteIt is accessible, just not convenient (for example, many outlets are at 20cm height - this was very popular when they were installed (about 10 years ago). Pulling the plug in case of emergency - not that bad. Doing it every time I start/stop using the device - no, thank you. Also, my new room has circuit breakers in it (and sockets at normal height, but not many are accessible from where I sit).Yes, I am lazy, that's why I want mechanical switches on the devices. Many of my devices have them (because they are old).

author: Alana
author_rank: Frequent Contributor
timestamp: October 05, 2012, 07:21:32 am
content: For me its another consumer gadget. This one may save some energy when properly used but...The key issue is "properly used". General public is so technically illiterate that they would propably wire this stuff incorrectly and then trow it away as useless not working device.Simple switchable extension cord is better here - especially that you would usually connect this to a set of devices like PC and its peripherals.

author: madires
author_rank: Super Contributor
timestamp: October 05, 2012, 10:52:05 am
content: Quote from: Alana on October 05, 2012, 07:21:32 amInexpensive, no problems with trigger levels, no stand-by power consumption, simple and effective!