Best case, that much solar generates about 38 horsepower for about 5 hours per day. The engine generates about 4000 horsepower. I would be astounded if this lowered fuel usage by 1% after you count the added weight of the batteries and electronics or if it lowered costs by anywhere near 1% due to the added maintenance issues.
That's not how modern trains generally work although it's possible that's how India's trains still work.
Usually there's a HEP (head-end power) generator on the locomotive and the rest of the coaches are just plugged into that/each other to distribute the power down the train. Most regions have standard connectors/voltages and such to make this pretty seamless.
Completely agree. They can be lucky if these panels power on board electricity and air conditioning (in new trains that have those) but that's about it.
A diesel locomotive and full trainsets is hundreds of tons heavy. You can't propel these with a handful of solar panels on top.
The panels will "power the lights, fans, and information display systems inside passenger coaches", which are currently powered by separate diesel engines, thus already incurring fuel & maintenance costs.
