A solar tracker may be used to tilt the PV array as the sun moves across the sky. With more hours of peak sun, a smaller pump and power system may be used, thus reducing overall cost. Tracking works best in clear sunny weather. It is less effective in cloudy climates and on short winter days. Storage is important, three to ten days storage may be required depending on climate and water usage.
Most systems use water storage rather than batteries, for simplicity.
A level sensor can turn the pump off when the water tank fills, to prevent overflow. A similar control can turn the pump off if the water source is drawn too low. Compared with windmills, solar pumps are less expensive, and much easier to install and maintain. They provide a more consistent supply of water. They can be installed in valleys and wooded areas where wind exposure is poor.