I don't have electric at my chicken pens. I only have a few weeks of freezing weather here so I built a small wooden box with a hole cut in the top big enough to hold the waterer. Put in some sort of insulation (hay) and a large hand warmer. The hand warmer lasts about 10 hours. They don't drink water at night so it doesn't mater. Just keeps water from freezing during the day so they can drink a little. Been doing this for 3 years. I even have one waterer in a plastic pot for plants. fits perfect in opening of pot. A rock in the bottom to hold it down, some hay, a hand warmer and waterer. Chickens drink all day in 20 degree weather. Plus it keeps the waterers up off the ground helping to keep them clean and the chickens don't loose as much water out of their beaks when drinking. They loose too much when waterer is on the ground trying to dip their beaks in it and hold water til they get their heads up.