This paper presents an evaluation of energy loss in photovoltaic power generation (PVG) under gradual aging caused by corrosion degradation. The mathematical model of the PVG takes into account the variation of the series resistance, which affects the maximum power output over time. A control system is designed, consisting of a DC/DC buck converter, a maximum power point tracking (MPPT) algorithm, and average voltage control, to ensure the PVG operates near its maximum power point despite degradation. The study compares two scenarios: with and without MPPT adjustment considering the aging process. Simulation results under variable power of solar irradiance show that adjusting MPPT parameters according to the aging state significantly improves energy harvesting efficiency. The findings emphasize the necessity of adapting MPPT strategies to account for PV aging, thereby enhancing the long-term performance and reliability of photovoltaic systems.