ABSTRACT
Pumping water with wind power is an old and well-studied technique. Nowadays, the most diffused wind turbines for water pumping are the American windmill, self-made Savonius rotors, and sail mills (a.k.a. Cretan or Mediterranean windmill). Slow wind turbines are ideal to drive positive displacement pumps, i.e., piston, diaphragm, screw, peristaltic, or lobe pumps, because of their high starting torque. Positive displacement pumps have many advantages for wind pumping systems: robustness, low operational speed and hence low wear and maintenance cost, low capital cost, easy reparation with simple tools, high efficiency—especially for piston and diaphragm pumps—and finally, the capacity to pump from deep wells.
