Transmission line power lost calculation?

Question

In typical transmission lines we have four wires that are made out of copper. Treat these lines as four resistors in parallel. Each of the wires has a diameter of 16 mm. What would be the power loss if the lines were made out of aluminum? Use resistivities of copper= 1.7x10^-8 ohms*m and aluminum =2.8X10^-8 ohms*m
I got an answer of 0.05MW but that's clearly wrong. Could someone give me hand? Thanks!

And I forgot... 497km of transmission line... unless I don't need that... and in that case, I guess I'm totally off in my logic

Thanks a lot!

Answer 1

Well
in electricity transmission the voltage is made high and the current is reduced to lower values.
In order to minimise the loss.
It has nothing to do with arrangements in parallel or series.
Loss are always additive.

For the power loss=current * resistance offered.
Also resistance={rho*length/(pi*radius^2)}
.........(eq1)
For both type of wires current is same length and radii are same.

Let power loss with aluminium and copper be Pal & Pcu and resistivity (rho) be Ral and Rcu

Pal/Pcu=Ral/Rcu ...........(eq2)

using equation 1 calculate power loss for any of the the wire of any type.
For overall power loss multiply by 4.

Using equation 2 calculate loss for other type of wire.