Quote from: jward on December 06, 2009, 11:47:52 AM
i believe the solar panel are used as a power source to operate the car doors for dumping ballast. this function used to be air operated, and the air cars were easy to spot because they had a second air line running between the cars.

the air dump cars are not to be confused with cars equipped with electronic air brakes, which have the usual air line and an electic cable running between the cars. these are usually unit train hoppers as the electonic braking only works if every car in the train is equipped.

I am still not huge fan of these panels.. Pretty expensive and efficiency is very low.