The thing is most birds can't see at night, so if they hear something they spook or are just a bit nervous about not being able to see. There have been places where something spooks a flock of wild birds off roost at night and they find a bunch of dead birds from flying into stuff due to not...
Maybe if you got enough windows the moonlight would be enough? Mine have no windows it's made of pallets so has spaces between every board and whole top is vented. Mine are noisy when I first shut the door and when they hear me coming or talking in morning but quiet and calm once settled in.
Anything you have on 24, 7 isn't going to be good for them but you have to have 12-14 hours of "daylight" for them to lay year round. I was saying more in regards to that then 24 hour light. So, if you wanted nighttime light too I would go with nightlight type light or even one of those that...
If you're supplementing light then no need for heat to encourage laying year round, use a florescent bul(those spiral looking cfl ones)...they give off light with very little to no heat