[Trachmyr]

Well, I am using a mod that increases the supply cost for (lower tech) engines, and requires a lot more engine to move your larger ships (i.e., a deystroyer needs 12 engines for spped 6... a battle cruiser needs 24!), but supply storage can hold 4x normal (it's needed with the engine mod I'm using)... so my reasons for no solar collectors on "tankers" is skewed (when you figure my large tankers have around 100K supply (but it goes fast!), it would take many years to refill the ship... and since a deystroyer with MK1 Ion engines will use 1800 supply per turn!)

So in the normal game, yes solar collectors work great (besides they lead to solar sails wich are also wonderful).