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Standby Electronics a Waste?
gnunick writes to tell us BBC News is reporting that UK citizens waste quite a bit of electricity each year by leaving electronic gadgets on standby or charging. Critics are arguing that standby mode on electronics are completely unnecessary and should be removed for a number of reasons. From the article: "To put it another way, the entire population of Glasgow could fly to New York and back again and the resulting emissions would still be less than that from devices left in sleep mode."
For us that live in coldish countries, and I'd place Scotland in this group, as long as you have regulated heating, heat from PSUs is just as good as any other heat.
I'm not saying we shouldn't conserve energy, but these kinds of calculations are often off by orders of magnitude.
616000 people is alot to fly. Think about it. That's 290 people per plane on 767's, or about 210 planes.
US TV: "Power" button on the TV itself and the one on the remote do exactly the same thing: switch between "on" and "standby". The only way to get it off is to unplug the mains cord.
European TV: Power button on the TV requires some finger pressure and physically disconnects the power, leaving the remote impotent. The "power" button on the remote only puts it into standby.
Of course there are exceptions but this has typically been the situation with my and my family's relatively modern CRT TVs on both continents.
"Patriotism is your conviction that this country is superior to all other countries because you were born in it." -- GBS
I know this might sound a little strange but I actually looked into getting a pre-pay meter installed so that I could find out how much leccy was costing me. I couldn't believe the cost of it though. You have to pay for the meter (if you want one installed by request), electricity costs more and you have the hassle of getting the card charged up.
I think it is absolutely stupid that we make the people that can least afford it pay the most for electricity.
I used to have a better sig but it broke.
None. Motion activated sensors would know if someone is in there who shouldn't be. I expect that local government could slash energy consumption by enforcing some kind of "out of hours" energy tax aimed at lights, computers etc. being left on over night. Companies would certainly enforce a turn off policy if it was hitting them in the wallet.
Not such a good test. Off is Off. Try leaving the monitor on for 10 hours, in standby. Then see how quickly it comes 'on'. Most CRT monitors leave a low voltage on the CRT filament, to keep it a bit warm, and sometimes a bit of keep-alive voltage in the high-voltage section, tho that isn't so useful today. The other logic and such is easy to start up, so while the filament comes to full temp in perhaps 5 seconds, everything else is alive and well. Flat panel monitors usually don't suffer from the delay in getting the backlight or plasma warmed up and fully on. Another good reason to spend 5x the cash and use 3x the natural resources to buy that HD panel. Go for it! rick
deleting the extra space after periods so i can stay relevant, yeah.
The amount of energy consumed by the first coil in the transformer (the one plugged into the wall) is proportional to the amount of energy consumed by the second coil (the one with the switch in it). This is because a coil stores energy like a capacitor. There is a finite amount of energy that the coil can store, so when that amount of energy has been stored, the coil will no longer draw a current (this works very much like a switch). When the stored energy is used, (for example, when a current is induced in the second coil), the coil will draw enough of a current to replace it. So, when you turn off the switch on the second coil, the first coil will cease to draw a current (of course, a small amount of energy will be dissapated in the form of heat, since there is no such thing as an ideal conductor). This is why your power company can put several step-down transformers in the power grid as electricity finds it's way from the generation plants to your house, and yet the load on the generation plants varies based upon the amount of power used, not by the number of transformers in the grid.
This is also a good concept to remember in the context of this discussion. A CRT uses a very large electro-magnetic coil. When you first power this coil up, it draws an enormous current (if your house is wired poorly, you will see your lights dim). That energy is not dissipated, however; rather, it is stored in the coil as an electromagnetic field. As that field is used to control the electron ray that generates the image on the screen, the electromagnetic field is consumed, and the coil draws a current (much smaller than the initial current) in order to replace it. When the CRT goes into standby, that electromagnetic field is no longer being consumed, and the only current being drawn represents the energy being dissipated as heat -- the more efficient the design, the lower this current will be. Remember, there is a large amount of energy stored in the coil, and a small amount of energy being consumed. When you switch off the CRT, the circuit of which the coil is a part is broken. When this circuit is broken, the entire electromagnetic field will be dissipated at once as an electromagnetic pulse, wasting all of the energy that it was storing. So, depending on how often you use it, standby may waste less energy that repetedly turning the device on and then off again.
No. kWh is NOT Kilowatts per hour, it's Kilowatts times hours, aka Kilowatt-hours.
On top of that, kWh/yr isn't wrong at all, it is merely an equivalent to Watts that makes it easier to calculate how much money (power companies usually charge by the kWh) is wasted by the device over the course of one year.
There are tons of devices on standby right now. They just don't ever bother to tell you, so you THINK it's off.
That's for sure. And there are even more devices where it isn't even standby - they're wasting power when "off" while providing no added functionality at all.
Anything with an A.C. adaptor feeding it is generally wasting power all of the time it is off. Switching designs help, but most adaptors have transformer core losses being fed all the time. I've found the same thing internally in some devices. Looking around the house, I found that my soldering stations and a table radio had the power switches wired after the transformer. Some things that have transformers or whole power supplies live all the time include doorbells, thermostats, garage door openers, VCRs, CD/DVD players, cable/satellite boxes, printers, and cable/DSL/dialup modems. I remember the shock at discovering that my old electric toothbrush had a stand with a field coil powered all the time. The coil was the powered portion of a motor to wind a spring in the hand-held unit.
Contrary to what the article says, cable boxes could be designed in a way where they could be shut down. The boxes could designed to handle revalidation only when a box is on. Data when off could be retained by a small amount of CMOS memory and a capacitor, or by using flash memory. Switching on the main power supply could be done by passing power for devices it feeds signal to through the box, and sensing load current to trigger starting the power supply. I don't think we should be paying for energy just to make someone's DRM work.
Devices with timers could be designed to run from charged capacitors. Small half-Farad capacitors are available. Some devices use lithium batteries, but I prefer to avoid those since they're toxic waste later.
I reduced the power consumption of an old L.E.D. digital alarm clock from 8 Watts to 1.2 Watts by replacing the transformer with a capacitive voltage divider, and eliminating the series-pass regulator by using S.C.R.s in place of two of the diodes in the bridge rectifier and controlling those. That savings was enough to power a bedroom color t.v. 2 hours a day.
I'd like to see someone design a cordless phone that was efficient enough to get by with powering the base unit from the phone line. They could at least use a switching supply for the base unit. Few people really need to have their microwave ovens programmed in advance to come on at a certain time. For years I kept my old microwave with a rotary knob mechanical timer. That oven didn't use any power when off. Most U.P.S.es could be designed to use less power once the battery is charged - they'd probably get better battery life too.
Devices that are powered all the time are at a greater risk of being fried by line surges.
On my old computer I wired an outlet box to the switched monitor power outlet. Then things like my modem and amplified speakers would have the power cut when the machine was off. If the machine had been designed to control that outlet in sleep mode, consumption could be cut even more. Having those items powered from the computers switching supply instead of transformers would save even more.
Sometimes when shopping I ask salespeople how many kilowatt hours per year a product uses when turned off. It's entertaining to see the weird looks I get. If a few more of us asked suppliers about these things it might speed design changes. Designers need to be educated about the need for reduced consumption also. Sometimes it seems like many don't worry about it except when too much heat is produced.
Consumers tend not to think of low power leeches as costing anything, but it adds up over the life of a product. Where I am it runs about $1 (U.S.) per month for every 10 Watts used continuously. In hot climates where air conditioning is used, waste costs are compounded with those to remove the waste heat from these devices.
Don't know, whether you have any specific emissions in mind, but I'd call this statement plain wrong. Currently total airflight energy use is about a quarter of total car traffic energy use (but admittedly airflight is growing at an alarming rate). Airplanes produce more emissions per distance, and also some particularily nasty types of pollution (water vapor in high altitudes, for instance, is a greenhouse factor), but it's not anywhere near surpassing car traffic in total, yet. (energy consumption in the UK. See page 14)
On standy: Yes, in many cases it makes life easier. However there is no wrong at all in 1) informing people that standby power usage is non-zero. Note that in some cases of bad design it's even quite considerable. Some inkjet printers use 15 Watts in standby - what for? 2) Pressure manufactures to make full-power-off reasonably easy.
Yes, there are areas other than standby, where (greater) amounts of energy can be saved. But also in many, many, many cases, summing up to hundreds or even thousands of megawatts, standby is just plain useless. Standby for a TV - ok, nice feature to have, if you like. Standby for a PC / printer / CD-/DVD-player? Heck, I'm typically right in front of those, when I want to start using them. What do I need standby for? Provide me with the option, fine, but give me an easy opportunity to switch them off fully, if only to reduce the risk of fire, or the damage done if lightning strikes nearby.