Ye, just to store garbage so it won't take up space on ur base, but sell it will give you more profit. I think that by collecting all the garbage from the generators and base you will get about 1000+ points in total !
Tip: if you want to save money a little - buy 12 trash bag, not 1 roll. 12 trash bags costs 12 points, 1 roll (which have 12 trash bags in it) costs 15 points. You will need a lot of trash bags, so...