Sorghum-Based Power Generation in Southern Ukraine: Energy and Environmental Assessment

An increase in energy demand, fossil fuel reserves depletion, and environmental issues are primary reasons for renewable energy use, including power generation. Bioenergy is the primary alternative to conventional hydrocarbon fuels. Biomass-based power generation is increasing due to some reasons, including a gradual decrease in the levelized cost of electricity and a reduction of carbon dioxide emissions. Sorghum is a promising energy crop for semi-arid climate zones, including southern Ukraine. It can be used for both biofuel production and power generation. However, there is a lack of methodology for energy and environmental assessments of sorghum-based power generation. Some possible technologies were analyzed. The novelty of this study is the accounting of energy consumed and carbon dioxide emissions during crop cultivation. We have determined that sorghum-based power plants can generate from 2 to 12 MWh per hectare. Their operation significantly reduces carbon dioxide emissions (from 613 to 3652 kg of carbon dioxide per hectare of sorghum silage cultivation). Sorghum-based biogas plants have energy and environmental advantages if they use co-generation technologies and utilize digestate as a biofertilizer. The utilization of digestate (obtained from silage production per hectare) substitutes up to 12.8 MWh of indirect energy. The results obtained can be used by farmers and authorities for bioenergy development.