I was thinking more like barges / rail cars that were essentially one giant battery, cycling back and forth. Even the most optimistic figure for current techno

I was thinking more like barges / rail cars that were essentially one giant battery, cycling back and forth. Even the most optimistic figure for current technology is still too high, about 0.03% / mile, so you only get about 200 miles (round trip) on a 6% budget. I suspect over-the-wire transmission losses are lower over that distance, but it's only a little impossible.