Appliances steal energy when they're off

[struggle4progress]

<snip> They'll turn down the thermostat, weather-strip the windows, maybe even replace that old furnace to combat projected heating increases of up to 72 percent between October and March.

But few will think to stop the steady siphoning of energy that occurs where they least suspect it: Many everyday appliances, when they're turned off, continue to consume an average $100 a year from the typical household, according to some estimates.

That will buy a week of groceries for the average Northeast Mississippi family. But applied to all of America's 103 million households, it adds up to more than $10 billion annually in lost energy.

Colorado-based Solar Energy International placed the nationwide expenditure much lower, estimating that America uses $3 billion annually to power electronics while they're turned off. That's still the equivalent output of 10 power plants - or the pollution of 6 million cars, the company said. <snip>

http://www.djournal.com/pages/story.asp?ID=203507&pub=1&div=News

[Lars39]

1. I'm probably dating myself here, but phantom energy users

was the theme to a Partridge Family episode in the '70s. :blush:

[struggle4progress]

3. The anti-environmentalism of the Reagan years, of course, drove ..

.. the country away from conservation

[Lars39]

8. Right into collective amnesia.

It's like the whole energy-saving concept has just been discovered.

[Coastie for Truth]

2. Ohmic losses in the Primary of step down transformers - even when

there's no load on the secondary. (I remember when I learned that in my "EE for Dummies" (every other engineering discipline except EE's) course. It was kind of counter intuitive - until you see a schematic -- then it makes sense.

[bullimiami]

4. its not that. its the standby modes, clocks, flashing leds etc...

in almost everything now. Most modern stuff never really goes off.

[Coastie for Truth]

5. Multimeter

My answer as based on multimeter readings acrosss the secondary, w/ and w/out a load.

Admitted, standby, LED's, clocks, currents below diode cutoff, currrents when Vbe-> 0.7V etc., are all factors.

[RC]

6. Don't forget the hysteresis loss in the core.

[Coastie for Truth]

7. You're going to make me get out my Circuits Book

(and ARRL Radio Amateurs Handbook) ;)

[Massacure]

9. I've been saying this for a while, and I'll say it again.

If your electrical sockets are not hardwired to turn off with the flip of the wall switch, get a power bar.

In my house for instance, each bottom electrical socket is live 24/7 and each top one is live only when the wall switch is on.

However I have a friend who has both electrical sockets live, and so they have to use a power bar to physically kill of the power source.

[skids]

10. Screw that, appliances steal energy when they are ON.

I mean, do you really think that a $50 PC power supply is at all efficient? No, the manufacturers don't care about that, just the shelf price. Your 300W PC power supply could use double that. Why do you think they have their own fans?

Oh and that box fan you have in the window, or the vaccuum cleaner? Unless it's special: shaded pole motor. Only 25% efficient. What you thought they'd spend the extra parts for a motor controller or even capacitative phase delay? Keep dreaming.

Oh, and as long as the extra power doesn't melt the plastic casing, they'll cut as many corners as they can on that wall wart. I guess if you use it to keep your feet warm then at least you get something for the money you pay to run it.

I'd just chalk it up to "you get what you pay for" and blame Walmart, but except for a very few product categories that the DOE was until a little while ago cracking down on with regulations (and EnergyStar as the carrot), it's very hard to buy any appliance, even a high-end one these days, without getting the energy waste shaft. You have to work at it, and hope the only people selling it aren't gougers.

At least you know a laptop is well designed... they have to be to preserve battery life and limit heat emissions. So if you get an efficient DC supply for it then we're talking. But sheesh.

[One_Life_To_Give]

14. Where do you get those numbers

Switchmode Power supplies were running 80% Efficient 20 years ago. A new 300W PC power supply should not have more than 75W of waste heat.

As for "Wall Warts", these low cost devices are linear power supplies and hence have typical efficiencies around 50% at full load. Virtually all of these will be approved by a NRTL to UL1310 or a equivalent in other jurisdictions. Which gives a maximum surface temperature rise of from 30 to 65 C depending upon thermal characteristics of the material.


Switchmode Power supplies have very high efficiency. Concidering that for a 5V Output, they loose 10% of the transformer output power to the switching diodes.

[skids]

15. I designed a switchmode power supply in college.

And they are very efficient, if they are designed well from an efficiency perspective. My design parameters in the lab were to reach 90% efficiency.

PC power supplies are designed very well, but not from an efficiency perspective. It's not a priority. The primary design factor with these things is component costs, not power savings.

A recent test showed 75%, as you note above, is about the norm.

http://www.hexus.net/content/item.php?item=1359&page=1

Lots of electronics are designed as such, and waste much more power as a result than their "phantom load" ever will.

(EDIT: BTW, you may want to look up "Schottky" diodes. 0.6V drop diodes in power applications are yesterday's news.)

[One_Life_To_Give]

16. Parts are Cheap

More bang for the buck in reducing labor. Even when manufacturing in SE Asia.

75% Isn't all that unreasonable. For a 300W power supply. You have about 30W loss in the power transformer. 15W in the Power Factor Correction Circuit. 5W in the Switching Fet. Plus Rectifier Loss, some I^2R and a fan to cool that little afterthought of space the system designers expect you to shoehorn the supply into.


FYI - Schottky's have been around for alot more than 20yrs. But you are still stuck with their 0.5V drop with any significant current. We used to play with Synchronus Rectification, but that was dropped when ECL, and the 2V Output faded.

[skids]

17. Right, but you pay more as the consumer for cheap parts.

...which was my point. The amount you "save" on the purchase price goes flying out your electrical socket in a year or two, unless you are an extremely light computer user.

BTW, here are the graphs from that report for anyone that's too busy to browse through it.

[Dogmudgeon]

11. It's "shoo the pigeon, ignore the hog".

Mom, Dad, and The Government all yell at us to turn the light off when we leave the room, but the cause of the problem is the inefficiency of the light bulb itself. In the case of standby modes of appliances, I've also seen serious discussion of the amount of energy wasted when these small appliances are powered up and turned off. The idea is that the power transformer is so lossy that, for instance, the LED clock it powers might as well be an old-style mechanical clock.

My mother obsessed for years over how many hundreds of dollars her heating pad cost her in electrical costs. It consumes 65 watts of energy and usually gets two hours' use per day; probably half an hour a day if you take a yearly average. Our local electrical costs are around 6.5 cents per kilowatt-hour. That's a buck and a half a year for one hour a day of use, instead of suffering back pains 24-7. Her chronic fear of being ripped off cost her MUCH more than a buck and a half of anxiety and pain. (The "stranded costs" charged by PECO -- our energy company -- come to as much as the electricity costs.)

The TV is also more efficient than she thought, too, but the clothes dryer and the electric range are different stories. Even the refrigerator is far less efficient than it could be. Going back to absorptive refrigeration with ammonia, and putting the engineering into safety instead of compressor technology, would seem to be a good trade-off; so-called acoustic refrigeration technology might even be a better use. And why are enormous and expensive heat pumps and air conditioners so popular when building a heat-exchanging grid of pipes underground is so much more efficient for reducing both heating and cooling needs?

And that favorite whipping-boy of an appliance, the microwave oven, gets very little use around my house. When it gets used 10 minutes a day total, that's very heavy use. It's also about 70 watt-hours of cooking power, plus whatever electrical losses come from the power supply and magnetron inefficiencies. That puts it on a par with the heating pad.

What we need isn't more pressure to turn off the lights, clocks, and computers, but better engineering -- immediately. Residential use of energy is about 10% of total energy use, and I see no reason why that can't be cut by 80% AND supplemented with off-grid technologies.

Automobiles, industrial processes, and public lighting are the big electricity and power hogs. All of these technologies could be radically re-engineered to use a fraction of the power they now use, and be made safer and more durable and useful in the process.

Developing good energy habits is a desirable thing until it starts causing anxiety; the bulk of the anxiety should be borne by our leaders and the "Captains of Industry" to increase efficiceny, develop new sources, and discourage the wholesale waste of energy that has been SOP since the first customer of George Westinghouse and Nikola Tesla's generator plugged in an electric light.

It's no big problem for the US Information Service to produce a booklet or PDF file that tells taxpayers they should use more weatherstripping and better grades of Fiberglas. But it takes real political will to tell industry to get its act together, and to pass laws and tax breaks to make that happen.

I'm willing to turn off the lights when I'm done using them and to spend the bucks for better weatherstripping. Most of us are. Now all we have to do is to demand that government and industry do their part.

--p!

[skids]

12. Amen to that n/t

[garybeck]

13. they're called "phantom loads"

the only way around them is to unplug then when they're not in use. It would be a lot of work to save a small amount of energy. Plus you'd have to reset the clock on all your appliances every day.

[Massacure]

18. or powerbars, or hardwiring the electrical socket to a wall switch.

The electricity has to be physically cut off somehow. My top electrical sockets are connected to the wall switch, so I use my phantom loads on that. The bottom sockets are live 24/7. It depends from house to house though.