I don't have supplemental lighting in my coop, I have 10 hens and I get between 8-10 eggs every single day for the past 3 years.
I have one 3 year old white leghorn and 1 2 year old Buff Orp that lay every other day. They get let out of the coop at about 7:30 am, and then they get out to free range outside the coop around 4-5 pm. The bottom part of their coop is screened on the sides and bottom so they start getting light as soon as they come down the steps.
Seems to be plenty of daylight for them.
In December, when I went to close the coop door at night, I did have to shine a light inside for a few minutes so they could find their perches, otherwise they would cluster around the top of the steps all night, but otherwise no other light.
