How do you get solar assembly parts?
If they’re not already lying around in the power monitoring, air locked room right before one of the many solar panel grids, then you should order them from cargo. They can also be found within the engineering department, occasionally.
Salvage from cargo department usually gets them via debrises, try ask cargo/salvage to researve or keep an eye out for those parts if you need them
(you can buy solar parts via cargo request ifrc, engi and solar airlocks also have solar parts crate in some maps)