I said something similar about the electric motor but you could add a menu to the alternator and allow to install upgrades in it regarding the efficiency or output. Or make a completely new way to transform huge amounts of SU into energy (for example the magnetic rotors in create new age) or you could make something completely different. It's just I'm sure many others have this issue when you want to convert a large amount of SU for example I have a 14 million su nuclear power plant. I would have to place like nearly a 1000 alternators which isn't ideal. Also it would just add more progression to the mod.