I found a outdoor solar/electric water aerator. It would have a 48 hour separate battery back up too. Both are designed for outdoor aquariums I would use a 5 gallon bucket. Drill holes for chicken nipples. Have the dual aerator system (a back up with a back up) in the 5 gallon bucket and it would create movement to keep the water from freezing. My winters are get to about 10 degrees. This would eliminate Heater systems and electric wire in water!!! Benefits Less risk of fire Won't boil off water Could work in power outage Cheaper than most nipple heated systems 3 different power systems Cons Untested Don't know how it will work with the nipples However, nothing ventured noting gained.