Modeling net energy balance of ethanol production from native warm season grasses

• The native warm grass species are potential candidate crops for bioenergy feedstock development initiative.
• Estimated mean NEV is higher in switchgrass compared to other species.
• Range distribution of NEV shows higher probability of having positive energy balance in all grass species.
• The distribution of energy output shows that biomass yield is an important factor in determining positive NEV.

There has been an increasing interest in the use of perennial grasses as potential feedstock for ethanol production. The characteristics which make perennial grasses attractive for bioenergy feedstock development initiative are their high yield potential and the high contents of lignin and cellulose. The objective of the study is to model energy input and output and simulate Net Energy Value (NEV) of producing ethanol from native warm season grasses. According to simulated results, the mean NEV of ethanol production from native warm season grasses considered in the analysis was positive. Mean NEV for switchgrass and eastern gammagrass was higher compared to Indiangrass and big bluestem. Although the probability of having positive NEV is high, there is a risk of having negative energy balance under low output scenarios.