This International Standard defines predicted short-term characteristics (instantaneous and for a typical daily period) of direct coupled photovoltaic (PV) water pumping systems. It also defines minimum actual performance values to be obtained on-site. It does not address PV pumping systems with batteries. The parameters defining the photovoltaic power generating system (PVPGS) and the standard days, used to provide data in figure 1, should be in accordance with IEC standards, in preparation, on the reference solar day.