Regenerative braking on trains seems like low-hanging fruit these days. Ah, yes, just did a bit of Googling and apparently it is standard equipment on most new

Regenerative braking on trains seems like low-hanging fruit these days. Ah, yes, just did a bit of Googling and apparently it is standard equipment on most new trains: http://www.climatetechwiki.org/technology/regenerative_braking_in_trains http://www.climatetechwiki.org/technology/regenerative_braki... Older, especially freight, trains where all power comes from locomotives still tend to lack regenerative braking though.