I guess power lines have a limit

[Sir Prometeus]

I'm currently playing a map where I have a dam at one corner and an industrial complex in the opposite corner. The dam is producing more electricity than the whole city needs, but it doesn't reach the industrial complex and the power lines touch the electricity grid of the complex. Do you know more or less how many kilometers does the electricty reach from the power plant? (assuming each square is 2x2 km)

EDIT: My bad, I was doing some changes in an industrial area in the middle and the grid got disconnected from the other half. Now it works perfectly.