system
Given the following post, respond as if you're commenting on Reddit:
human
[LoTR] So I need a fairly permanent light source in my deep and twisted cavern - torches simply won't do...

So I got this idea where the taskmasters under me can impale goblins and orcs to the walls and then hang parts of elven swords (*goodness don't put the whole thing there or one of the lucky buggers will have a weapon*) on the wall opposite it.  Where'd I get the swords from?  Don't worry about that part right now.  The result (hopefully) being that the presence of live but immobile orcs/goblins will make the swordparts glow bluish forever and my ~~dungeon~~ er, underground palace will have a sustainable source of energy powering its lights.

Does this go wrong anywhere?  Do the batteries wear out?  Do I have to deal with plot deciding not to light up the metal occasionally?
gpt
That glow isn't anywhere near as bright as a torch and the enchanted elven weapons will be expensive and/or time-consuming to acquire and you're putting lives at risk to capture orcs and you also need to buy or raise or scavenge a constant supply of orc food.

This is easily the worst lighting solution I've ever heard of. How could it possibly be preferable to torches?