Earlier quoted context omitted.
The Joule is basically the currency of the Federation. While most of the time in the Federation people don't use currency and get what they need/want, in Voyager because there suddenly was scarcity again they implemented replicator rationing.
I wasn't the biggest fan of Voyager, I saw episodes here and there so maybe someone can explain this idea to me. I saw a few of the episodes where they described the rationing of replicator usage due to some shortage of something. I never understood this as the replicators are described as transforming a base material into near anything a person asks for which required energy to perform this task. The ship was the so…
- not sure about the over-abundance of energy. I remember several episodes where energy shortage was a plot point. It's also possible that assembling matter atom-by-atom takes a non-trivial amount of energy compared to warp travel.
- I also thought the replicators did have certain limitations - eg. you can't replicate living beings. If the "resolution" was limited at the atomic level, you would still need a certain amount of hydrogen and oxygen to replicate water.