Thermodynamic Sustainability Analysis of Sweet Sorghum Production with Renewable Energy Integration

In response to rising global energy demand and sustainability targets, assessing the energy-related efficiency of agricultural products has become a critical issue. Sweet sorghum is widely recognized as a promising energy crop for sustainable biofuel production, thanks to its low water requirements and high biomass productivity. To the best of the authors’ knowledge, this study provides the first comprehensive cumulative exergy-based evaluation of sweet sorghum production by simultaneously assessing its energy, exergy, and environmental performance using five key indicators: Cumulative Energy Consumption (CEnC, 718.48 MJ/ton), Cumulative Exergy Consumption (CExC, 2031.42 MJ/ton), Cumulative CO2 Emission (CCO2E, 124.01 kg CO2/ton), Cumulative Degree of Perfection (CDP, 2.8) and Renewability Index (RI, 0.64), based on field level data for the production of one ton of sweet sorghum. Input-based analysis revealed that electricity consumption accounted for the largest share of both energy and exergy use, amounting to 334.85 MJ/ton and 1396.32 MJ/ton, respectively. At the same time, irrigation water was identified as a major contributor to carbon emissions. The integration of renewable electricity sources substantially improved system performance, increasing the CDP to 6.32 and the RI to 0.84, corresponding to more than a twofold increase in exergy efficiency and a shift toward a predominantly renewable production system. Overall, the findings highlight the strong potential of sweet sorghum as a sustainable biofuel feedstock and underline the importance of integrated policy and management approaches that simultaneously address energy quality, exergy losses, and carbon emissions in agricultural energy systems.