What Are The Advantages Of Hydraulic Pumps? All pumps require some form of external power source to operate. Hydraulic pumps use the kinetic energy of water as their main source of operation because they convert mechanical energy into a new form of hydrostatic energy. The hydraulic pump can be powered by motors running on gasoline, diesel, natural gas or electricity. Some types of hydraulic pumps usually supply water by gravity, and they pump water from the same source they pump out. In addition to the use of natural elements, these types of continuous running pumps are often used for water supply on farms. A good example is a windmill, which uses a hydraulic pump to lift water from deep above the ground in the wind above. http://www.oilmaxhydraulic.com/gear-pumps/