Discussion in 'Physics' started by eagle55, Mar 9, 2010.
why dont we use 'soil' as electrical conductor?
Some areas do. Overall though, the losses aren't worth it. Look up line transmission on Wikipedia.
Most places use grounding or earthing rods, ground & earth being other names for soil?
Electrical conduction thru earth is possible only due to conductive materials/minerals which constitute what we broadly term as 'soil'. However, soil is just but a part of what we term as 'earth' or 'ground'. The soil will enable conduction only if it is rich in electrically conductive resources like moisture salts and/or minerals!
The earth can and has been used as the return path in [monopolar] DC power transmission.
Tesla tried that.
I have a question for the OP. Are you wondering why we don't put soil in wires where the copper is? For instance, take a tube, fill it with soil and call it a wire?
I can understand, with the price of copper these days, why you would think it a good idea. Unfortunately the amount of additive you would have to add to the soil, and testing to be sure of content, would ultimately cost more than the copper.
They exist, as I said. The ground is at best a barely passable conductor, you would waste more electricity heating the soil than you would save on the return wire IMO.
There seems to be a lot of confusion about the term "earthing" One should distinguish between the broad electrical use of the word and the electronic use of the word.
In normal electrical reticulation (110 or 220v), the earth connection is used for safety more than anything else. It is not the return path of the electricity from the scource, but could under certain circumstances , just be that. The reason being that in any normal reticulation setup for industrial or residential power, the centre tap of the step-down 3 phase transformer (from the power grid) is grounded. That means a earth spike (a copper or similar rod is inserted into the ground). From this point the "neutral" wire is then run. In effect the earth and the neutral at the point of origin is the same, but after a couple of meters the resistance of the earth(soil) is a lot more than the direct cable. The earth at your house is therefore a safety factor on which I can expand.
But I get the idea that I am rambling on to much, so if there is any more interest I will carry on.
I wonder if studiot's post in this thread - http://forum.allaboutcircuits.com/showthread.php?t=37880 - wouldn't fit well into this discussion?