A Method for Evaluating Unregulated Solar Irrigation Pumping Systems: Results and Observations

While existing pump testing standards assume fixed voltage power supplies, solar pumps are supplied by DC voltage from photovoltaics. In lower-cost implementations of these systems, a lack of voltage or current regulating power electronics results in performance which is affected by the inherent current vs. voltage profile of the photovoltaic modules; this behavior must therefore be emulated during system performance evaluations. This paper describes an experimental method for estimating the efficiency of unregulated solar irrigation pumps and validates the method using an experimental testbed.