During cold weather the water in stock watering tanks can ice over or freeze solid. During such conditions, the stock can suffer or even die from thirst. To prevent or minimize that, those responsible for the stock either have to visit the stock watering tank and break the ice or provide de-icers. However, many stock watering tanks are in locations where it is inconvenient or expensive to connect de-icers to the power grid or to provide a conventional (e.g., diesel-powered) electricity generator.
USPTO Backgrounds
USPTO Backgrounds