You don't give any details of what modules you have and why you have them. But here's how I use module storage these days, after hitting the limit before, as you have now.
I realise you may not want to go all 'book-keeper' on this, but I would at least suggest listing what you've got to weed out any module duplication.
I hope that helped you.
Good point. I am not in game but at a high level I have a bit of most things now. I finished the Engineer unlocks a little while back so have played with most things. Kept those half decent rolls. There are maybe around 10 or so items that are low usage ones, maybe that could go or have lower end rolls. Those started to get sold to sort out my combat build on the Python. Like most pilots I have a few configs on the Python, from trader, passenger, mission running and combat. Much of the core stays, but optional internals change a lot and things like cargo racks or passenger cabins unmodded still stay in storage so I can quickly change without hunting for a rebuy somewhere. For each setup there, it might be 5 modules on average. Then I have a couple Dirty Drive rolls for a few size drives stored. These were rolled recently have several months of gather the mats so even though they do not have a use I cannot bring myself to sell them.
Then I have a range of weapons, which I use across any of the ships depending on what I need. Might be a good 15-20 various ones stored in different sizes. Room to narrow this down if I really needed to but thinking its better to store on a ship for now.
There are probably a few things I have forgotten .. oh Shield Boosters and the like .. a bunch of those stored for various heavy or resistance builds.
I do have spares as I said but don't feel I am excessively hoarding things.
I can surely sell some across the board, but after a good year working up the Engineers, all that time getting mats/data (most of which I felt I was throwing out along the way lol) its a hard pill to swallow (even if there might not be an immediate home for some of these modules right now).
Maybe I need to bite the bullet and get a couple Pythons and just not respec, rather change to the one I want pending the situation etc? Dunno .. feel the game is pushing me this way.