Geothermal energy was a renewable energy source that uses geothermal fluids to generate electricity. Besides, geothermal fluids contain noncondensable gases (NCGs) which can be an negative impact for power plant and environment. NCGs can decrease power output and work in Geothermal Power Plant (GPP). In addition, the higher concentration of NCGs, Carbondioxide, contribute to Global warming potential in the world. Therefore, selection of NCG Removal system (GRS) becomes a major concen at planning and basic design stage which aims to maximize power output and minimize cost of GPP in a long-term perspective by modeling to simulate dry steam of GPPs to examine the thermodynamic and economical performance of GRS. This model is validated against actual data in Kamojang unit-1 with low disprecancy level (<5% error). To Optimize the model, 3 GRS configuration was investigated, Steam Jet Ejector with low of motive steam, Steam Jet Ejector with high of motive steam, and Compressor System. The allowable condenser and separator pressure was defined to set constraints. Under the best configuration (Compressor system), the gross power output and overall exergetic efficiency are 53.6 MW and 26%, respectively. Furthermore, by 1.5% of Interest rate, Net Present Value of the proposed plant was 3,467.