Lines are in the works now: http://k2radio.com/new-power-lines-will-carry-wyoming-wind-energy-to-california/
The century old grid structure will not be a good fit for renewables so the question will be whether there is willingness to restructure the aging grid to make it a better fit not so much as to whether alternatives are possible. Horses were replaced with rail and then IC transportation because in the long run infrastructure investment produced a better system. If you looked at the cost of the rail and road costs some would have wanted to stay with the horse-some countries basically did and are found in the third world.