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], 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 point). Additionally, the steps proposed to compute the RMSE are incorrect. In addition, by using the same method as proposed by the authors in [1], it has been found that their results are misleading. Moreover, the algorithms classified as accurate, according to authors classification, gives wrong results. © 2019 Elsevier Ltd