I have heard about artificial lighting forever it seems. I have to be honest; I never tried it. I guess I'm an all natural kinda gal. When I compare the price of the equipment against the idea of just getting a few extra hens......possibly leghorns to insure a guarantee of eggs, I feel like going with the latter.
If you have something installed, that will cost you. If you just run some cords and buy a light; that will cost you. Then....and I know this won't be much, but there is the electric charges. And then I really don't want to draw attention to my coop at night. Not all of us are living in a perfect neighborhood.
I do have a light in my coop, but I only turn it on when I need to go there for something and turn it right off when I'm done. I only have it, so I can brood chicks directly in the coop if I need to. It must be switched on from the house.
I feel like we have different seasons and the chickens bodies adjust to them accordingly. When it gets colder, they might need to concentrate on keeping warmer and some of their energy normally spent on producing eggs, might be spent on warming up.
Now if I should ever want to try and see if more light would be a plus, I think I would do it by removing 2 or 3 sheets of roofing and replace them with clear fiberglass, but that would only help me for the daylight hours.