What's the difference in cost between installing say, a 115 kv line and a 500 kv line?

I know that the cost of cable is a large part of the expense, but environmental work, pylon construction, maintenance, and other factors are probably very large as well.

As a follow up question, is there a real difference in environmental footprint between 115 kv and 500 kv outside raw materials used for the line? And possibly tower design and clearance around the towers?

(Even though I've worked on power projects, it's an area where I don't claim a lot of understanding (to put it mildly).)

... they'll want to go with the 500 kv setup so they can build new coal plants at the end of it later.

I'm guessing a 500 kv line of equal capacity to a 115 kv line uses less raw materials overall, but the mandated clearances around the higher voltage lines are greater.

If we lived in a civilized nation, we might use more underground HVDC transmission lines:

http://www.abb.com/cawp/GAD02181/C1256D71001E0037C12568350027FEFD.aspx

Volts = "The volt is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power".
http://en.wikipedia.org/wiki/Volt

Watt = power per second
http://en.wikipedia.org/wiki/Watt

Amps = Electric Charge per second
http://en.wikipedia.org/wiki/Ampere

Volts, Watts and Amps are related to each other is the following Formula:
Watts = Volts/Amps

Ohm = Resistance (Direct currents only, impedance in AC Currents)
http://en.wikipedia.org/wiki/Ohm

Ohm are best seen in Ohm' law:
Amps = Volts/Ohms
http://en.wikipedia.org/wiki/Ohm%27s_law
But also read :
http://hypertextbook.com/physics/electricity/resistance/
Which points out Ohm's law is more a guideline then a true scientific law. It also points out the Resistance of various elements the three important ones are as follows:

Aluminum 26.5
Copper 17.1
Silver = 15.9

Thus Copper has about 1/3 less Resistance to Electrical charge then Aluminum, the big issue is then the price of each AND the weight needed to be kept up. Silver is even better then Copper, but the price difference between Copper and Silver rules out Silver as a electrical wiring except in certain special situations.

Once you looked at the Resistance (ohms) then you look at the Voltage, Amps and Wattage. Remember the Formula: Volts=Watts/Amps

A good place to calculate between materials (Through mostly for areas):
http://www.allmeasures.com/Formulae/static/formulae/electrical_resistivity/2.htm

Given the above what is the difference between a 115Kv line and an 500 Kv Line?

First lets look at the test for Electrical Conductivity for aluminum
Then for Copper for 1000 meter long cable 10x10Cm square (I know cables are round but 10/10 is easier to calculate then the area of a Circle so I am using a Square for the Cable width):
That comes to:
0.0016775708773695 ohms
http://www.allmeasures.com/Formulae/d1/d2/d3/Results2_2.asp?formula=3&material=Copper+

Now for Aluminum for the same length and width:
0.026518164942985943
http://www.allmeasures.com/Formulae/d1/d2/d3/Results2_2.asp?formula=3&material=Aluminum+

As you can see Copper is preferred unless we have a some other reason to pick aluminum (Generally price AND the cost of installing the Wiring, aluminum is a lot lighter).

The switch from a 115kv to a 500 kv means a need for a much thicker wire to handle the increase electrical charge going through the wire. Remember Weigh increase by roughly a factor OF three AS YOU DOUBLE THICKNESS. Thus you are increasing the thickness of the wire by a factor of Five (May be less) the weight will have to increase by a factor of 15. This means an increase in the strength of the towers to handle the increase weight.

The main reason to go to 500 kv, is to increase electrical power through the system. A 115kv system is limited by its Amperage and Voltage, if you increase both (and that is what they are during going to a 500 kv Line) you can increase Wattage per hour, which is the real goal, for people use WATTS.


Just same observation if no one else answers your question.

Because you can get a much larger cross section of aluminum for the same weight as copper. That's one reason it's heavily utilized in power lines.

Hysteresis Loss, Eddy Current Loss, and Insulator Leakage are all major players.

Jeeeezzzz. Read your definitions again. OHM is the measurement of electrical impedance (in an AC circuit), NOT the volt.

"Watts = Volts/Amps" No, Watts = Volts X Amps.

I hope you are not designing electrical transmission systems.

I should NOT do things at 1:00am after being up since 8:00am AND being sick all day. Notice I tried to stay with the definitions wikipedia supplied me, if the definition are wrong correct them (and on wikipedia). If the mistake is mine, I have to blame being up at 1:00 am. Also notice I did make a reference that other would know more then I, I am going back 30 years since I dealt with Electric Current on more then turning it on or off.

All I was going by is certain facts about weight, volume and Current. I was trying to answer the question to the best of my ability. I probably should have deferred to others, but I made the mistake of trying to answer a question from what limited research I could get over the net. I have to defer to people who use these definitions on a more regular basis then I, so I have to defer to you.

Checking my references, I notice I mistyped the correct formula, Under the Volts Reference the formula is given as:

Volts = Watt/Amps instead of what I wrote above.

I regret the mistake, but I do NOT use the formula on any type of basis and why I made the references I did in case I did make a mistake. If I was designing any electrical equipment I would refer it to someone with expertise in the field, and if that could not be done have what ever I do double checked for any errors (such as the one you found). I am NOT any type of engineer, so my knowledge is one of just the basics. All I was trying to do is answer the question, and I notice no one has, What are the extra costs of going from a 115 kv system to a 500 kv system, i.e. how thicker must the copper wiring be? How heavier the towers to hold the heavier cables. Would the use of Aluminum be justify do to its reduce weight? No one has answer those questions. The question may have NO answer, given the lack of information but I tried to answer his question as best as I could.

As long as you're not an EE!:-)

At least you gave it a try. I AM an electronics engineer, and I wouldn't have tried to answer the question as there are just too many variables and things I am not current (pun) on. (I also learned early in my EE career not to be designing shit at 1:00 AM! :eyes: )

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