Indonesia is currently trying to transition from fossil fuel energy to renewable energy. From the six types of renewable energy identified for their potential, solar energy has the highest potential compared to other types of renewable energy, which is 207.8 GWp. One of the ways to utilize this incredible potential of solar energy is by installing solar PV systems on the roof of the building. This study aims to conduct a techno-economic evaluation of a solar PV system installed on the roof of a factory building through a case study of a multinational company in Indonesia. The evaluation result shows that the solar PV system has produced 7.4 GWh of electricity from January to December 2021, and the performance ratio is between 63.8% and 84.58%. The electricity produced is used as a backup power supply from the State Electricity Company in Indonesia. The economic evaluation shows that the solar PV systems have a positive net present value with 10.8 years of investment return. CO2 saved emission by using this clean energy is calculated at 168,253 ton CO₂ equivalent for 25 years of solar PV system lifetime.