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Efficient Power Supply Contest
A reader writes: "In the June (paper) issue of Scientific American, there is a mini-article descibing the energy being wasted by power supplies in computers. Those things are only 60-70% efficient in converting line-voltage AC to low-voltage DC, and there are so many millions of them out there that a modest efficiency increase could trim $1billion or more from the annual energy costs of the USA. Well, various governmental agencies are seeking to get improved power-supply efficiency into the marketplace. The central "clearinghouse" site is at efficientpowersupplies.org, and details of their contest are in this PDF."
Its a step in the right direction, alot, alot of people burn electricity like its free.
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Energy costs at a company I worked for in SiValley were becoming such a factor that they dropped the use of all CRT monitors and towers in the work place. They switched us all to thinkpads. Now, on a small level this is very inefficient, but from a large perspective, I am assuming the energy cost savings would be enormous. My tower/crt costs me at least $25+ per month at home. I could easily lease a lowlevel laptop for that.
Aj
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especially since i use several UPSes which add another layer of inefficiency.
i want an efficient AC to DC UPS which connects directly to a DC powersupply for my box(en).
that would rock.
don't get me started on an entire DC house running off of a fuel cell and/or wind/water generators. woot!
Does anyone have anything to say about the efficiency of wallwarts (those small powersupply bricks)? What about having them plugged into the wall but not plugged into any device?
I'm not sure that cumulatively saving a billion dollars accomplishes anything.
The difference per person won't be felt.
The difference in income for the power companies might be felt.
I don't feel sorry for them, but they are a big part of our economy.
Like any other industry I would expect them to raise their price to maintain their income.
Sure, this is contrary to supply and demand but most of our economy is.
What if the same idea where applied to computers. Right next to the standard wall outlet would be a world standardized jack with six or eight pins for each of the required voltages.
Low voltage computer mains would make UPS systems less complicated too.
I've even heard of vendors who make telco friendly rackmount PC's that take 48v DC mains.
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http://www.mini-box.com
Why cast the argument in such statist terms: "trim $1billion or more from the annual energy costs of the USA"?
Nobody except liberals consider 'the annual energy costs of the USA'. People do (and should) consider THEIR annual energy costs. The fact that this decreases the amount of money spent in the USA is a secondary benefit, directly derived from the primary, i.e. the reduction in cost to the individual. The USA is not the Borg, and no country should be. Treating the entire country as one entity is the first step on a long, dark road.
I want to delete my account but Slashdot doesn't allow it.
Reminds me of the one about the Canadian Government buildings being determined to cost $200 a year per sq ft to maintain, so they replaced the CRTs with LCDs because they used less space, and therefore would cost less to maintain.
*sigh*
If you could be told what you can see or read, then it follows that you could be told what to say or think - BoC
Every electronic doodad I can think of has an AC/DC adapter. It's not just an issue with computers.
And it would be nice to get rid of those bulky AC/DC power bricks too...
Carl
Vote Libertarian
First he fried his egg on the proc not the PSU but, that is efficent thinking. Anytime you can put something to use you are saving engery. Normally in electronics(unless you are building a space heater) you think of heat generated by resistance like in the proc as waste. If you can take that heat and cook you breakfast with it then its no longer waste but a valible product of the computer. If you want the supreme example find Bacardi's or take their plant tour. The have NO waste materials. Every single by product of makeing their Rum is either resuesd in some prior part of the process in makeing the next batch maintaining the grounds or sold to someone else who can use the stuff.
I remember measuring the power factor of various serverers that we were evaluating at come point, and discovering that it will vary greatly between cheap and expensive servers. Some of the cheapo ones had a pf of .4, while high-end Intel server have a pf above .9. The interesting thing is that most people (even and especially those that sell and service computer hardware) don't even know what pf is and why it is important (unless they are electrical engineers or have been directly involved in building large computing facilities where it directly impacts the cost of the electrical infrastructure).
Last night, while I was out watching my power meter spin and spin and spin... It got me thinking about a digital whole house power meter that I could monitor. I want to be able to get a true RMS power meter that can measure 100+ amps AC, and outputs the data somehow. I'll write a little app to track and graph it, and work on lowering my overall house power usage.
:)
Todd
Anyone know of such a device? There are industrial ones out there, but I haven't seen a reasonable priced one for household use.
Hey, I am an electrical engineer; maybe I should just make one.
Assume 100 for the crt and 150 for the tower. Assume the crt is own 10 hours per day and the tower is on 24 and power costs 0.10 USD per kw/h.
.10 is 0.44 USD per day or $13.33 per month.
( 100 * 8) + (150 * 24) = 4400 Watts or 4.4 kw/h
4.4 kw *
I was way high.
Except those flourescent bulbs put out painfully ugly light. The spectrum is way off and may cause eye damage that could result in much greater long term costs than the electricity.
White LED lights on the other hand are looking promising.
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
Was the outcome good on some of those govenrment investments? Sure.
Do I think private industry and individuals could have and would have stepped up a bit more had the government not waved money at them? Sure.
Do I think that the outcome would have been very similar to the one we have now? Sure.
Do I like it when the government decides how to invest other peoples' money for them? No.
Do I like it when money is thrown at problems at a whim? No.
Were there a lot of failed investments? Sure. Public transit, social security, public education, welfare, most forms of recycling, etc etc etc.
Do I like it when people act like the government has a spotless record on investments, when in reality there were many failed ventures? No.
Do I like it when people act like tossing cash at a problem's way makes it go away? NO!
Do I like it when people act like the act of government cash tossing or cash tossing of any form is the only solution? ABSOLUTE NO!
Do I like it when people act like things wouldn't have happened without that aforementioned government cash tossing? DOUBLE ABSOLUTE NO!
Do I think that the cost of a solution can outweigh the benefit of a solution? LOTS OF TIMES!
Should you quit encouraging the government to whisk away what's hidden snugly in my wallet and bank account to research things that you think might be a problem, with an outcome likely to be what you wanted in the first place?! AAAAAAAAAH!
My head hurts now, all thanks to you...
Until Slashdot fixes the funny modifier, use insightful or interesting. The poster knows your intentions.
That's not a totally inane rational.
Each worker needs a minimum amount of space to get their work done. My two old CRTs took up my entire desk, requiring me to have another desk in order to do any work that required paper. The new LCDs have freed enough space on my desk that I can use it for both purposes. This would allow them to mandate removal of my other desk and reduction in size of my cubbyhole.
If everyone's space needs can be reduced by a few square feet, we can pack in more people without the current occupants feeling more squished. Alternatively, we can improve the working environment for cramped people without actually investing in new office space.
Thus if I save 2 square feet at $200 per foot, I can actually justify spending $400 on a new monitor. I can spend more on monitors for workers in space limited work areas.
This is not a political statement. This is not legal advice. It's a frick'n Slasdot post. However: I'm Running For
The flicker causes some people not to blink as often as they should, resulting in overly dry eyes, which can cause cornea damage.
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
There are varying grades of flourescents, and varying spectra and color temperatures that you can buy.
I too doubt the eye damage thing. Less blinking? Is there something to back that up?
What is the highest that I can possibly score on a reply to a question that has a score of 1? Even if I am so Interesting and Funny, what is it worth?
anyway...
"suitable resistor and smoothing capacitor ) straight into some voltage regulators"
You answered your own question. A voltage reg requires a resistor. Resistors leak heat, i.e. power equals current squared time resistance. The more current, the more power wasted.
Yes, it would approach 100% efficency, as the current approached zero.
Bring the USA into line with the rest of the world and use 230VAC instead of 110V. This halves the current through the wiring, thus halving the power wasted. And cables need only half the copper for the lower current, saving raw materials into the bargain.
Here is one example of a DC-input ATX power supply. It uses 24V in, so it's up to you how you want to mix'n'match utility AC and alternate DC sources. For more general info along those lines, check out Home Power.
--The more you know, the less you know.
This is where you are wrong. Some (I would not dare say "most") interesting innovation do not present an interesting business proposition. Take the Internet; I am not quite sure the telco would have waken one day and say "let's build a cooperative packet network where I will carry your client's traffic for free if you agree to carry mine". If it was not for ARPAnet, we would be using Compuserve and Prodigy today IMHO.
Just as governement-sponsored research is not systematically good, it's not systematically bad either. Don't throw the baby with the bathwater.
:wq
So you want to say that a PSU that has 10W heat with 100W load, which double to 20W as the components age, is in ANY way worse than a normal PSU that wasted 30W to begin with?
Depends how the design was handled. If the components were placed to handle 30W, then no, it's strictly better. The problem is that most people don't do a full thermal analysis on a design - they simply do it, then check its temperatures while running, and adjust things if it's too bad.
This means that most (cheap) designs are marginal - that is, they don't work a significant amount outside of their specified thermal envelope. A design that's marginal at 10W that encounters 20W is likely to fare worse than a design that's marginal at 30W that encounters 40W. Most tolerances built in are percentages.
So you're right, if it's a quality design, with a lot of tolerance built in. However, I doubt that most power supplies are quality designs...
60 watts for your laptop? I think you're looking at the wrong figure. That's probably the power output to your laptop, not the power input. On my laptop, the power transformer does 75W (15V @ 5A) out, but 120-144W (1.2A @ 100V or 0.6 @ 240V) in. It's between 63% and 52% efficient by those numbers. My laptop may consume less than half the power my desktop does, but it comes at a price. A poor keyboard, poor pointing device, slow hard drive, mediocre video chip and a slow response rate on the high resolution LCD.
I used up all my sick days, so I'm calling in dead.
I think you focus on the greater issue of conservation shouldn't be such a microcosm.
The national power grid operates at a whopping 18% efficiency. That's right, 82% of the energy made by power plants is lost to transmission, heat, etc. The real solution to conservation is to use locally-generated power to reduce transmission and heat loss. If homes were using Microturbines, they could generate their own power AND heat their water. From my best recollections, these things get 86% efficiency and generate enough power for 4 homes.
Let's not forget about solar panels (great for the southwest!) and wind turbines (also good for the southwest, and the midwest). Really, if we want to improve efficiency, let's go straight to the source, eh?
There is a difference between "insightful" and "inciteful" other than spelling.
High efficiency, high-current (500W+, where PC supplies are headed) are not cheap to produce.
That is true simply because there is no demand for them. Since most people don't know about power supply efficiency when buying PCs, the PC manufacturer gets the cheapest power supply, which is also likely to be inefficient. The inefficient power supplies become the most popular, and the high-quality ones start to cost more. In all likelihood, a high-quality power supply would cost about as much as a low-quality one if produced in large quantities.
The cheapo power supplies used in PCs cost less than a tenth of that. Many of them don't have protection circuitry and forged UL certifications are common. Most won't deliver their rated load, and many, if loaded up to their rated load, will burn out, or worse, catch fire.
The real problem is to get to 90-95% efficiency at $0.10/watt.