This study successfully demonstrated the fermentation of Napier grass was optimum at 5%TS based on
the kinetics parameters. Economic analysis indicated that the costs of equipment for biogas production
from Napier grass were 112.9 US$; it can be replaced LPG 282.8 US $/year. In term of cost to maintain
Napier grass was 77.4 US$ per year. Napier grass can grow 87 ton/ha/year. It was a high production rate
per year. B/C ratio was greater than 1 suggested that the Napier grass is considered as a potential energy
crop.