Just going to point out that the sun in the elder scrolls universe isn't a ball of plasma and is infact a big ass hole in the fabric of reality from when Magnus pussies out of creation. So it is entirely possible that plants could grow without sunlight in the elder scrolls.

Also for any more specialized lore junkies are vampires hurt by the raw Magicka from the sun or is it more of a raw lumens thing?

Also also the Empire had a space program, do with that what you will.