Recently, the energy price has been accelerated and brought out various difficulties. Under the energy crisis, lots of countries try to get the fossil fuel much more. In addition, they research and develop the renewable energy to utilize the practical fields. Renewable energy sources are photovoltaic, solar thermal, bio-energy, wind power and geothermal energy, etc.. These resources have advantages in limitless existence and the environmental affect which do no give rise to any problems to nature. Therefore, these utilization of these resources will be widen to make an energy while existence of the fossil fuel will be decreased to limit. In this paper, it aimed to analyzing the life cycle $CO_2$ in the renewable energy system, focused on the equipment component. The condition for analysis duration is 40 elapsed-year. The payback period of Photovoltaic energy would be calculated in 3.5 years in $CO_2$ emission of the system component. The solar thermal is 2 years and the geothermal energy is 1 year and wind system is about 10 years.