A microgrid is a power network section including distributed generators, storage systems, and loads. A “Power to Gas” (PtG) system is a rising technology that produces synthetic methane (or similar gas) by using electricity and carbon dioxide extracted from the flue gases. Recently, Turkey has been preparing to make strict sanctions on energy producers to decrease the greenhouse gas emissions due to the Paris Agreement. Additionally, it is struggling with the outage of imported natural gas. Accordingly, PtG systems may handle both the problems of natural gas shortages and carbon dioxide emissions. This study aims to propose methods to optimally design and schedule a PtG system integrated microgrid by Mixed-Integer Nonlinear Programming (MINLP). PtG system is assumed to be installed, whereas other equipment, consisting of renewable and non-renewable sourced generators and a battery, is nominated as selection candidates. Two different integrated gasification combined cycle generators and one combined heat and power generator are selected to be installed. The model does not prefer to choose renewable sourced generators, such as wind turbines and solar panels, for the investigated location due to fixed and maintenance costs, weather conditions, and demand levels.