There have been and still are a large number of photovoltaic (PV) powered pumping demonstrations and applications throughout the world. It has been estimated that approximately 700 PV powered pumping systems have been installed around the developing world in the last three years, and there are possibly another 100 systems in use in the developed world.Manufacturers, international lending organizations, and government agencies have also conducted numerous studies of photovoltaic pumping. Numerous combinations of a photovoltaic power supply, a pump, motor, and controls --a basic PV powered pumping system --have been studied,tested, and used throughout the world for several years.