Doubt power for the lights would be a problem on a nuclear sub.
And I don’t think we have any more diesel subs.
Space is probably more of a problem than power. But as they use up their initial stores, maybe that space could be put to use.
I actually went inside a retired sub while visiting Israel. This was a venerable model, but still smelled like diesel oil. I was amazed at the lack of space. No one of any decent size could possibly have lived aboard this thing, and I am small. It was an amazing experience in the Israel Naval Museum in Haifa.
They’ll use all that space currently wasted for torpedoes and missiles!
Space is probably more of a problem than power.
this