Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Other
Publication Acceptance Date: 7/15/1998
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: A solar-photovoltaic (PV) AC water pumping system consisting of 60 thin-film cadmium telluride, 18-Watt solar panels, inverter/controller, submersible motor, and centrifugal pump has been tested since June 1995. The inverter/controller converted the DC power output of the panels to either single or three-phase AC variable voltage/frequency electricity. The controller sampled the DC voltage and determined when the water pumpin system should operate. The output from the solar panels diminished steadily for about 18 months, requiring the addition of 10 panels to maintain the desired power level. During the first half of the testing time, a single-phase submersible motor was used, but during the last half of the testing a three-phase motor was used. The efficiency of all components was much better operating as three-phase rather than as single-phase, and the inverter/controller provided much smoother voltage. The average daily water pumped increased from 4.2 m**3 for single phase to 7.0 m**3 for three phase; or about a 75% increase in water available for livestock. Using a three-phase 0.56 kW submersible motor with a 12-stage 0.56 kW centrifugal pump, enough water could be pumped from a 40 m well to water 115 cattle.