TL;DR
energy transmission should have a diminishing returnWhat ?
with the transmission of energy over land you should have a diminishing return.I would suggest something like, every 10 poles you loose like 1% of the energy you transport.
Why ?
with nuclear reactors it is not really necessary to produce energy at more then one place.you can transport the energy over thousands of poles without any disadvantage.
with a diminishing return you have to build more energy stations when you get later in the game.