f50gt1: My question is this: If I put three Shield Generators on my ship, do they stack (i.e. Shields generate 3 times faster)?
DeMignon: No, afaik they don't.
Shield Generator Enhancer Mk I decreases regeneration time to 65%, Mk II to 55% and Mk III to 50%, thus doubling regeneration rate is as fast as it gets, no matter how many modules. Think of it like this: You only have one Shield Generator and it will be enhanced by the best Enhancer module available on board.
I was afraid that would be the case. It's a pity they made ships with so many hard points, yet not allow modules to stack, or created enough modules to fill the points. Yes there are mines and such, but in privateer one, you could load up twenty missiles per two launchers, this is limited to one per point, and I'm assuming it's the same for mines. You could also upgrade software in Privateer one, why not in the second? (Or did I miss this in the shop?).
So even though I have a ship that can hold two shield generators, and two gun coolers and two MKII repair droids. The doubles are just a waste of space and money...