In this paper, the maximum power point (MPP) of a photovoltaic (PV) source is estimated using the proposed explicit current-voltage (I- V) expression. The conversion of implicit expression of current to explicit expression of I-V equation is carried out using Maclaurin series expansion. The explicit I-V function of the PV module is validated with the I-V characteristics obtained from an implicit expression by considering various types of modules. The MPP of a PV module is estimated from the proposed explicit function of an I-V relationship under uniform and non-uniform conditions using MATLAB program. The MPP of a module under different solar irradiance conditions estimated using the proposed method is compared with the MPP obtained using other different existing methods. The results show that not only the calculated MPP of a module is close to the actual MPP values but also the computational time to obtain the MPP is less. The percentage (%) of deviation of calculated maximum power obtained by using the proposed technique compared to experimentally obtained maximum power is minimal. Also, the accuracy of the method, which is proposed here, is used and verified to calculate the global MPP of a PV system under different shading patterns. IEEE