In this study, a cost optimization and sensitivity analysis were carried out for the deployment of a photovoltaic (PV) system in a semiconductor facility in South Korea. The Microgrid software (HOMER) was used to simulate the performance of the system for the electrical load profile of a representative semiconductor manufacturing facility. We performed cost optimizations for grid-only, PV/battery, and grid/PV systems for the semiconductor facility. The environmental impact was evaluated by estimating the amount of polluting emissions. The grid-only system showed the lowest net present cost and cost of energy, and by connecting the PV system to the grid, the amount of pollutants was decreased by 10% with a renewable fraction 9%. If we consider a renewable PV/battery system, a 100% renewable fraction and zero emissions can be achieved. In addition, sensitivity analyses were performed. Under the assumption that PV costs decrease and grid costs increase, it was found that grid/PV and grid/PV/battery systems are economically more competitive than grid-only systems. Additionally, as feed-in tariffs are introduced to South Korea, it can be shown that a semiconductor facility with a PV system installed could generate profit by selling excess energy.