Have some info they maybe in the works. Similar to how a Toyota Pirus works. Anybody hear anything about the loco builders looking into this? 
Look at the Forum topics under “Green Goat”. This is an operational hybrid diesel engined switcher utilizing a bank of batteries charged up by a 300 HP engine that does the work of a 2000 HP straight switcher.
GE had an announcement on a hybrid some time back. You can access their web site for info