I talked with a physics guy and his high-schooler son yesterday at the laundromat.
They'd seen SPIRIT and wanted to talk about it for his son's class project.
The father's a railroad guy, and using his physics background to drag locomotive technology up to 1998 automotive hybrid levels.
Rather than lose all the train's braking energy to the locomotive's rooftop resistor heat, they're finally going to install Li-ion batteries to capture it all.
I'd mentioned the 670-hp worth of power that 12% photovoltaic array could capture atop a 1-mile train, and he seemed to get the light bulb moment.
Anyway, it's good news, to hear that our diesel-hybrid-electric trains will finally be diesel-hybrid-electric in the way we experience automobiles.