In this manuscript, a derated MPPT (Maximum Power Peak Tracking) scheme is proposed, for grid integrated solar PV system. Since, due to reverse power flow towards the grid, the voltage on PCC (Point of Common Coupling) increases. According to the norms of the grid, only up to 10% increment in PCC voltage is acceptable. In this situation, when PCC voltage exceeds the limit, then a single option is de-rate the MPPT operation. In this work, a derated MPPT scheme is introduced, which is the modified form of the most popular perturb and observe (PO) MPPT algorithm. The Derated PO (DPO) MPPT algorithm operates for MPP (Maximum Power Peak) when PCC voltage is under the limit. However, when PCC voltage exceeds the limit, then DPO operates on a specific point where PCC voltage is just below the upper limit. The performance of the DPO MPPT algorithm is validated through MATLAB simulation on different types of grid condition as well as in dynamic variation of solar irradiance condition. © 2019 Galgotias University.