Throughout the US there are tens of thousands of wastewater ponds with intense treatment for small cities and industries (e.g., the food processing industry), and perhaps just as many reactor basins in wastewater plants for large cities. In most cities, wastewater aeration uses more electricity than any other single power use in the city, and the aeration is significantly oversized due to the need for proper mixing of the water and oxygen. Over 400 solar-powered circulators have been deployed in recent years to reduce aeration run-time while maintaining or improving the water quality. Solar-powered circulators also increase odor control and reduce biosolid volume at the bottom or the pond or basin, thus reducing costs to dredge and dispose the biosolids. In critical applications, the circulators can be connected to shore power to maintain a battery charge through extended periods of rain, fog and snow.