We're been using this one the past few years: https://www.amazon.com/Automatic-Chicken-Coop-Door-Standard/dp/B01EN3O4MY https://www.amazon.com/Automatic-Chicke

We're been using this one the past few years: https://www.amazon.com/Automatic-Chicken-Coop-Door-Standard/dp/B01EN3O4MY https://www.amazon.com/Automatic-Chicken-Coop-Door-Standard/... It has a solar panel and rechargeable battery and you program in your lat/long and optional + or - times for the door to remain open or close around sunrise and sunset. It works well. Of course, you could hack something up with a micro-controller to do the same thing rather easily.