Quantification and use of rice husk in decentralized electricity generation in Rio Grande do Sul State, Brazil

Rice husk (RH) use in electricity generation can help mitigate environmental issues and generate profits, specifically in Rio Grande do Sul (RS) state, Brazil. The objectives of this study are to estimate the RH surplus in RS and evaluate the feasibility of its use in electricity generation. RH production in RS is estimated at 755 thousand tons per year, which is generated by 230 rice mills. Geographic Information System helped in showing RH's power capacity for each municipality in RS. This large amount of residue has a potential output of 479.5 MW and 322.7 GWh per year. 43.1 % of this potential comes from 214 mills (93 % of total) whose power plants' capacity is lower than 800 kW, thus classified as Micro Thermal Power Plants (MTPs). Sensitivity analysis demonstrates that the lower the MTP capacity, the more sensitive it is to economic parameters. Furthermore, all MTPs evaluated only showed profitability when Certificates of Emissions Reduction were included, showing the importance of such income. This study aims at presenting an overview of RH's energy potential inasmuch as the upside and downside of this kind of energy system.