These methods require more numerous sources of water and a way to deliver water from fenced streams, Since range lands are often far from the electric grid, PV is usually the best option for pumping new wells in those situations. Centrifugal pumps do not require regular maintenance or replacement of the pumping mechanism and most have brushless, fluid filled motors that are also maintenance-free. They are recommended for low to high water requirements and heads of up to 400 feet. Diaphragm pumps are positive displacement pumps that contain flexible membranes which must be replaced periodically when they are worn. All diaphragm pumps are powered by DC brushed motors which also require periodic rebuilding.
Some pumps require controllers to protect their motors and to run more efficiently.
Manufacturers will specify if one is required with their pump. The size of the PV system and the type of water pump required for a given water pump application depends primarily on the daily water requirement, the total dynamic head, the efficiency of the pump and the available insulation.