The ability to stuff the battery featured in the linked video on this page inside of a train, and have it run on electricity from a battery.
I was with my sister one dy at a restaurant, and I was explaining my idea to her for my future railroad company. All of the people in my family have almost no idea how costly railway electrification is, so she asked me why didn't I just build a Maglev?
A: I wanted to use pre-existing track.
B: Outrageously expensive.
C: Too many resources would be used by the project.
So that almost ended her hopes and dreams of a green railway, so then she asked me why I couldn't install catenaries. I told her that would be too expensive, and that reminded me that I could possibly use a third rail and the P32AC-DM. I still thought that was going to be too expensive, and then the thought came to me:
Judging by the internal structure of a train, why can't I just rip out the engine and put a battery in it's place?
I did a little bit of research into this, but then realized that, currently, there is no existing battery efficient enough to pull off the task of powering an entire locomotive. Then, my father sent me an e-mail with a link to this video. Now, with this new battery, my idea is almost complete. I just have to take a slightly deeper look into the inner mechanics of the average train, and before you know it, we'll have the P42DC-E (E for Electric). How about that?