Funny enough, Portal 2 takes place in an old Michigan salt mine
Maybe all of those old test chambers were vitrified in salt instead of just concrete, come to think of it...
At it's peak the system used ~3MW power plant to run the system.
[1] or at least were; the project was shutdown in 2004 and while the paths of the antenna lines still seem to be visible on satellite photos[2] it looks like the lines themselves may have been removed.
[2] The transmission station itself is at https://goo.gl/maps/q5BwduBqbBpAaf1L9 with the 28 mile antenna segment running roughly north south just to the west, one 14 mile segment running east-west a little to the north of the facility and the second to the south.