sehari@iastate.edu (Sehari Babak) (06/05/91)
Recently, there were much talk about way to reduce the energy consumption. This not only saves money, but eventually saves life as well. Having this in mind, I am curious that haw much energy would we save. If we gold plate all Al wires that is used for transportation of the energy? Let us assume we have one mile of wire. It would probably costs around say $1000 to $2000 to gold plate this wire. Now depending on the current that passes through this wire, we might save $2000 to $4000 in the first year alone. This saving might increase even further, if the oil prices goes up again, which is a very likely possibility due to declining oil reserves of the world. Has any research been conducted in this way of saving energy.
jshapiro@mcs213a.cs.umr.edu (Jeff Shapiro) (06/05/91)
In article <sehari.676081817@du248-12.cc.iastate.edu> sehari@iastate.edu (Sehari Babak) writes: >Recently, there were much talk about way to reduce the energy consumption. >This not only saves money, but eventually saves life as well. > >Having this in mind, I am curious that haw much energy would we save. If >we gold plate all Al wires that is used for transportation of the energy? [Stuff deleted] I don't have my CRC handy but I'm pretty sure that gold is only used for electrical contacts because it is pretty much inert. I think both copper and aluminum have better resistivities than gold. Anybody have any numbers? Jeff Shapiro jshapiro@cs.umr.edu
wreck@fmsrl7.UUCP (Ron Carter) (06/05/91)
In article <sehari.676081817@du248-12.cc.iastate.edu> sehari@iastate.edu (Sehari Babak) writes: >... I am curious that haw much energy would we save. If >we gold plate all Al wires that is used for transportation of the energy? > >Has any research been conducted in this way of saving energy. Conduct your own research. It's easy! 1.) Compute the amount of gold a dollar will buy. (It's about $350 for 1 Troy ounce, or 1/14 lb). 2.) Compute the amount of aluminum a dollar will buy. (Scrap is selling for around $1/lb; new might be $2.) 3.) Compute the diameter of a meter-long gold wire containing your $1 of gold. 4.) Compute the diameter of a meter-long aluminum wire containing your $1 of aluminum. 5.) Using values for impedance of metals (available in the CRC Handbook of Chemistry and Physics), compute the resistance of the two meter-long wires. The wire with the lower resistance would deliver power with smaller losses for the same cost, and is the energy-saving winner. So. What answer did you come up with?
digex@world.std.com (doug e humphrey) (06/05/91)
For your calculations, scrap aluminum, good bulk scrap and not a bunch of crushed cans that need a lot more processing, sells for 40 to 50 cents per pound; I am pretty sure that the finished product, in shape to make waire, or even already drawn as wire, will cost way under $2.00 per pound. Doug
henry@zoo.toronto.edu (Henry Spencer) (06/05/91)
In article <sehari.676081817@du248-12.cc.iastate.edu> sehari@iastate.edu (Sehari Babak) writes: >Having this in mind, I am curious that haw much energy would we save. If >we gold plate all Al wires that is used for transportation of the energy? Uh, what makes you think gold plating will save energy? The only effect of a thin layer of gold plating on the surface, aside from making the cables pretty :-), will be to make them a bit more corrosion-resistant. Corrosion is not normally a serious problem anyway. To improve the conductivity of the cables, you're going to have to replace the bulk material, not just add a plated surface. P.S. Silver would be a better choice than gold for bulk conductivity. -- "We're thinking about upgrading from | Henry Spencer @ U of Toronto Zoology SunOS 4.1.1 to SunOS 3.5." | henry@zoo.toronto.edu utzoo!henry
touch@gradient.cis.upenn.edu (Joseph D. Touch) (06/06/91)
In article <1991Jun5.163512.1314@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >In article <sehari.676081817@du248-12.cc.iastate.edu> sehari@iastate.edu (Sehari Babak) writes: >>Having this in mind, I am curious that haw much energy would we save. If >>we gold plate all Al wires that is used for transportation of the energy? > >Uh, what makes you think gold plating will save energy? > >To improve the conductivity of the cables, you're going to have to replace >the bulk material, not just add a plated surface. Are you sure? I thought AC travelled on the surface of the wire, not in the bulk, or is this just a very high frequency phenomenon? In that case, plating would help a bit - in fact, you could use the plating without the interior bulk (ala waveguides). Joe Touch University of Pennsylvania Dept of Computer and Information Science touch@cis.upenn.edu
simnet@ssc-vax.UUCP (Mark R Poulson) (06/06/91)
In article <43275@fmsrl7.UUCP>, wreck@fmsrl7.UUCP (Ron Carter) writes: > In article <sehari.676081817@du248-12.cc.iastate.edu> sehari@iastate.edu (Sehari Babak) writes: > >... I am curious that haw much energy would we save. If > >we gold plate all Al wires that is used for transportation of the energy? Do you want to plate the wires or make them solid gold? Plating is only going to help where the cable is terminated. Solid gold conductors would be quite expensive. Note that power lines are rather large cable carrying tens (or is it hundreds?) of amperes and gold ones couldn't be a much smaller gauge. If you think that because the current is AC (so most of the current is carried on the outside of the cable) you should notice that 60Hz AC is not too effected by the skin effect so current flows throughout all of the cable. Resistance in terminations could be overcome by making much larger terminations out of cheap aluminum instead of small expensive gold ones. I think you would save more money by using larger diameter aluminum cable (or parallel cables of the size used now) to give a lower resistive loss. Mark
ssave@ole.UUCP (Shailendra Save) (06/06/91)
From article <1991Jun5.163512.1314@zoo.toronto.edu>, by henry@zoo.toronto.edu (Henry Spencer): > > Uh, what makes you think gold plating will save energy? The only effect > of a thin layer of gold plating on the surface, aside from making the cables > pretty :-), will be to make them a bit more corrosion-resistant. Corrosion > is not normally a serious problem anyway. There is something known as the skin effect, due to which, the higher the frequence, the closer to the skin the current travels. This is one of the reasons why the cables are never solid, but a bundle of thinner wires. The other reason is of course to have some tensile strength. With this knowledge, I would think that the bulk would not matter so much as the "skins" of the individual wires. So we would have to just coat the outermost wires with gold(so that they don't corrode) but coat all the inner wires with silver (since they are not in contact with external factors) so as to reduce resistivity to current through it. Just my 2.76 yen worth (today's rate). Someone please verify the skin effect stuff. Shailendra ssave@caen.engin.umich.edu sumax!ole.uucp!ssave
luns@spocom.guild.org (Luns Tee) (06/06/91)
jshapiro@mcs213a.cs.umr.edu (Jeff Shapiro) writes: > I don't have my CRC handy but I'm pretty sure that gold is only used for > electrical contacts because it is pretty much inert. I think both copper > and aluminum have better resistivities than gold. Gold is third and Aluminum is fifth on the list. Specific resistances (resistance of a wire one foot long, one mil diameter, at 20 deg C) are Silver 9.9 Copper 10.4 Gold 14.7 Chromium 15.6 Aluminum 17.0 Titanium 19.2 Sodium 25.9 Magnesium 26.2 Calcium 27.6 Rhodium 28.2 Tungsten 30.1 Manganese 30.1 Molybdenum 31.9 Zinc 34.6 Iridium 36.7 Potassium 36.7 Nickel 41.7 Cadmium 42.3 Indium 50.3 do I need to go on? :-) Anyway, Aluminum is used instead of copper in power lines because its cheaper. Ontario Hydro says that they've had problems with people stealing copper power lines. =:-O As for Gold (and Chromium) plating, you're right on the money.
elec140@csc.canterbury.ac.nz (06/06/91)
In article <1987@ole.UUCP>, ssave@ole.UUCP (Shailendra Save) writes: > There is something known as the skin effect, due to which, the > higher the frequence, the closer to the skin the current travels. > This is one of the reasons why the cables are never solid, but a > bundle of thinner wires. The other reason is of course to have some > tensile strength. > With this knowledge, I would think that the bulk would not matter > so much as the "skins" of the individual wires. So we would have to > just coat the outermost wires with gold(so that they don't corrode) > but coat all the inner wires with silver (since they are not in > contact with external factors) so as to reduce resistivity to > current through it. > > Just my 2.76 yen worth (today's rate). > > Someone please verify the skin effect stuff. What you say is correct as far as it goes. However the "skin depth" (ie the thickness of the "skin" carrying most of the current) is dependent on frequency. The higher the frequency the thiner the "skin" and you've got problems. However from memory, the skin depth at 50 Hz (yes I'm in that part of the world) is about 10 mm, which equates to a lot of gold !-) ********************************************************* Chris Kaiser Postgrad - Elec Eng Dept Canterbury University Christchurch, NEW ZEALAND E.MAIL: kaiser@elec.canterbury.ac.nz ********************************************************* "When you're fresh out of lawyers You don't know how good it's gonna feel" - Al Stewart, 1988 *********************************************************
wlsmith@valve.heart.rri.uwo.ca (Wayne L. Smith) (06/07/91)
In article <7Fs532w164w@spocom.guild.org> luns@spocom.guild.org (Luns Tee) writes: > Anyway, Aluminum is used instead of copper in power lines because its >cheaper. Ontario Hydro says that they've had problems with people >stealing copper power lines. =:-O I've heard stories of people tying copper lines to the back of their pick-ups and driving down country roads, ripping the lines off the poles.
dave@seas.gwu.edu (Dave Owczarek) (06/07/91)
In article <7Fs532w164w@spocom.guild.org> luns@spocom.guild.org (Luns Tee) writes: > > Anyway, Aluminum is used instead of copper in power lines because its >cheaper. Ontario Hydro says that they've had problems with people >stealing copper power lines. =:-O > Today's Washington Post reports that an asteroid has been found orbiting the Sun at a distance of about 20 million miles from Earth (closest point). It apparently contains 10000 tons of gold and 100000 tons of platinum, as well as 10 billion tons of iron and 1 billion tons of nickel. Its estimated worth was put at around 1 trillion dollars. Lets haul it in and make gold power lines out of it. :^) -Dave -- ---------------------------------------------------------------------------- Dave Owczarek, Operations Team dave@seas.gwu.edu or uunet!seas.gwu.edu!dave The George Washington University Engineering Computing Facility, Wash. D.C. ----------------------------------------------------------------------------
gary@ke4zv.UUCP (Gary Coffman) (06/08/91)
In article <1987@ole.UUCP> ssave@ole.UUCP (Shailendra Save) writes: > > Someone please verify the skin effect stuff. Skin effect is of negligable effect at power line frequencies, bulk conductivity still rules. If you raise the frequency to take advantage of skin effect, you start to run into radiation losses as the length of the conductors becomes an appreciable fraction of a wavelength. For typical spans, most of the electrical energy would be lost to radiation across only one span at less than 2 Mhz. 300/Mhz defines the wavelength in meters for a given frequency. Long distance transmission today uses DC at ultra high voltage to minimize the amount of current the conductor is required to carry for a given amount of power. Power loss is proportional to I^2*R, so the lower the current, the lower the loss for a given conductor. Use of DC rather than AC eliminates radiation losses over the long spans of long distance power lines. Gary
gibbons@csn.org (Hugh Gibbons) (06/11/91)
In article <sehari.676081817@du248-12.cc.iastate.edu> sehari@iastate.edu (Sehari Babak) writes: >Recently, there were much talk about way to reduce the energy consumption. >This not only saves money, but eventually saves life as well. > >Having this in mind, I am curious that haw much energy would we save. If >we gold plate all Al wires that is used for transportation of the energy? > >Let us assume we have one mile of wire. It would probably costs around say >$1000 to $2000 to gold plate this wire. Now depending on the current that >passes through this wire, we might save $2000 to $4000 in the first year >alone. This saving might increase even further, if the oil prices goes up >again, which is a very likely possibility due to declining oil reserves of >the world. > >Has any research been conducted in this way of saving energy. Electricity is transmitted at near-dc (quasi-static) frequencies; under these conditions, the skin depth (depth of penetration of the curent into the wire )is very long, so the wire would have to be essentially solid gold to really get a significant reduction in resistance. By the way, silver is a better conductor. -- -------------------- :-) Hugh Gibbons (-: --------------------