This research paper proposes a straight-line approximation-based maximum power point tracking (MPPT) algorithm using open circuit voltage of Photovoltaic (PV) module and then employs an iterative based optimization technique for determining the optimum step-size to extract maximum energy from PV-module. The proposed algorithm is compared with the conventional PO method in terms of maximum energy extraction at different step sizes. The results obtained show that the proposed algorithm extracts more energy at optimized step size and at other different step sizes during fast and slow varying global horizontal irradiance (GHI) parameter. The simulation results also show that the proposed method is much faster than the conventional PO algorithm in finding the MPP for same step size. The fast-finding maximum power point (MPP) by the proposed algorithm not only allows increasing the overall system efficiency but also helps by extracting more energy from PV module especially for rapid changing weather parameters.