This study comments on a manuscript “Important notes on parameter estimation of solar photovoltaic cell”, [Energy conversion and management, 2019.111870.] [1] introduced by Gnetchejo et al. It is noteworthy that, in [1], an another approach is proposed for computing the objective function; root mean square error (RMSE) computations that depends on the measured current in all of its terms unlike the literature where it is difference between measured and estimated currents. Moreover, the flowchart for computing the RMSE shows the authors took the value of RMSE at only one point of the results (last value). Additionally, the steps proposed to compute the RMSE are incorrect. In this comment, by using the same method as proposed by the authors in [1], it has been shown that results of [1] are misleading. Overall, the algorithms classified as accurate, according to authors classification, leads to wrong results.