Board Thread:Questions and Answers/@comment-5441128-20180718231606/@comment-262546-20180719075359

Even with all the knowledge they've gained from the Atlantis database, reverse engineering ZPM's are probably a bit too complex for them to actually do just yet (kind of like how reverse engineering a Stargate is probably a bit too complex as well).

Note how in The Last Man, alternate-timeline Rodney placed a mark 12 naquadah generator on Atlantis somewhere between 1-3 decades after the year 2008. Thus, if humanity was still developing / manufacturing / using naquqdah generators by that time, that could indicate that they still haven't figured out how to reverse engineer ZPMs even in all that time.