I pushed my chickens to lay through the winter a few years back by putting a light on a timer in the henhouse with them...it can be any light, mine was a regular old 60w bulb...it worked fine. I didn't do it anymore after that because we had more eggs than we needed during that time, plus I suspect it'll cause the birds to lay out early. They're born with a finite number of eggs inside them, and once those are gone...