I'm currently learning about the transportation of electrical energy through power lines. I now know that transporting current at a very high voltage cause minimal power loss compared to transporting it at a very high amperage.
However, one of the formulas I've been given to calculate power loss is P=V^2/R, which in this context produces ridiculously high numbers. For example,
P=40,000^2/1 (assuming the cable has a resistance of 1 ohm) = 1,600MW. This obviously isn't what happens in reality. So, is the formula only applicable in certain circumstances? Should I only use it when working with closed circuits?