Effect of solar radiation correlations on system sizing: PV pumping case

The precise determination of solar radiation intensity is important for accurate system sizing. For PV pumping system case, the issue becomes more important since inaccurate solar radiation data nonlinearly reflected to the calculations. Inappropriate solar radiation model selection for a specific design site is a major cause for inaccurate system sizing. The differences in power output of a PV pumping system due to using some solar radiation correlations are examined here. The results are then compared with those of long-term solar radiation measurements. It is reported that the system sizing with the measurements and the most appropriate correlation for the application site significantly differ since the errors in predicting solar radiation data are nonlinearly propagated to the system power output.