EV train conversion?

[metromizer]

I wonder how much electrical power is needed to drive, say an 8-car freight train? I know those things run on electricity from on-board Diesel powered generators, but I wonder if short runs could be made with batteries alone?

The idea has been floated to use a boxcar full of forklift batteries charged by solar. Aren't photovoltaic panels only good for 100watts/hr/square meter of panel?

If you had an established route, what instruments would a guy use to discover the total electrical requirements needed to replace the ICE generator, for the purpose of sizing a charging station and on-board battery requirements?

Seems it's the same considerations one uses to design an electric car...