you can ca ou your dilithium each day without ever seeing Sol. Its just a meesly 420? 469? ...something around there. You dont even have to go there to cash in or do the founery mission daily.
If you really want to have tons of ectra dil sitting waiting to be refined sure, you can go do it. but its really pointless to earn more then 8k a day and Eta, Orilleus, and B'Tran Dailies cover it all, as well as go by quickly.