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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."
Great idea! There are so many things that we keep doing in a wasteful and inelegant way just because it's "good enough" (or at least was in the past -- when things get wider distribution, problems are magnified).
Power supplies are a good example, as are cars (so much wasted energy -- hybrids are better in that regard, though, like in converting braking energy into electrical energy that can be re-used later to help the engine when it's at its most inefficient RPM levels).
Treehugger? Treehugger... Treehugger!
Also one should take into consideration someone using a 500W is only getting 350 at 70% effecient. If you had a PS that was 90%, you would only need a 400W.
Now that you have a smaller PS, you might could drop a fan or two. This now decreases your power load on your new 400W.
Savings on effeciency == savings everywhere
How much extra spent on power supplies? High efficiency, high-current (500W+, where PC supplies are headed) are not cheap to produce.
It would be far better if government worked to reduce the amount of petroleum being consumed through initiatives to encourage telecommuting, locating companies in locations that don't require commuting in the first place, and research into fuel cells and hybrid vehicles.
..don't panic
In short, there is almost NO reason to not use those fluorescent bulbs and it would result in a far greater amount of energy savings right now...
You wouldn't want to provide most of these voltages remotely, because of the current draw. At higher current values, the resistance of the wire becomes more of a factor, and you'd either need very short runs (kind of defeats the purpose of a distributed run), or you'd need high current wires, which have a large diameter (wire guage). Think of running jumper cable type wires from room to room and you'd get an idea of what would be required.
You could provide a single higher voltage that gets regulated down as needed at the equipment, but you'd still have to deal with the current levels, just not as high.
Nunc Tutus Exitus Computarus.
I'm a professional engineer, and have done several designs of switchers that were better than 95% efficient. But they cost more to make, so dream on, it's not going to happen in the mainstream with out some sort of mandate. The tricks are simple, better inductors (cost more for bigger copper and more ferrite), synchronous rectification (fet and drive costs more than a diode), taking care to be clever about quiescent currents (more engineering time) and so forth.
Doug Coulter, owner
C-Lab
http://clab.mystarband.net
You're way off. In 1994, the U.S. alone produced over 1.3 billions tons of carbon (not CO2, just carbon; the CO2 weighs even more than that).
while about 500 million tons were produced by natural causes.
Natural causes do not "produce" CO2. They merely recycle carbon. The CO2 emissions of living organisms have no net effect on the global carbon balance, because all they are doing is moving it around, from the atmosphere into the biosphere and back again.
It is true that methane emissions from cows are an issue. This is because methane is many, many times more effective than CO2 at trapping heat. But the net amount of carbon still remains the same.
All the 'inefficiency' in your computer gets emitted as heat, noise, RF or light.
Ultimately, most of the non-heat forms of energy loss get turned into heat in the surroundings when they get absorbed by something, like a wall.
So if you are trying to maintain your house at a higher temperature than it is outside, then all the lost energy from your computer goes to do useful work heating your surroundings. Hence a 100% power efficient computer.
Now if we could efficiently generate electricity, we might have an efficient total system. I don't see that happening soon.
Evil people are out to get you.
It is a popular Slashdot cliché that small, weakly administered sites use desktop PIII systems with IIS, with the Windows 2000 Server install disc titled in felt pen, on the corporate DSL line and in the same room as the Coke machine and copier.
To no small degree that cliché is based upon a grain of truth. I've seen those sites. It is also true that such sites are not the exclusively Microsoft. But the parent of your post knows his audience and isn't ashamed to go for the easy performance.
This is a boring sig
The space savings are significant in the computer labs especially. Students now have room to put their books out in front of them, between themselves and the screen. (we had crowded labs before, the desks are narrow and close together.).
The power savings are good. Before, students would forget to turn off the monitors when class was done. It still happens, but when those LCD's go into powersave mode, they use almost nothing.
The rooms stay sooo much cooler. Our AC was always running in the computer labs before, with 30 17" CRT's going (and PC's). but the LCD's produce so little heat that the room stays nice and cool, and the AC is off more than it is on. (lots of energy savings there).
My back is very thankfull, and every time i have to move a CRT monitor across campus, I am reminded about how thankfull my back is.
What are we going to do tonight Brain?