In this study, we investigate the integration of biocomposting into microbial fuel cells (MFCs) to address the challenges of power generation and organic waste management. Thus, we analyzed the impact of biocomposting on power generation and microbial community dynamics, employing biocompost mixtures of organic matter (OM) and straw in different ratios over 30 days. The results indicated that the most effective configuration was C-MFC4, with 25% OM and 75% straw, achieving a maximum volumetric power density of 1547.93 mW/m3 (at an external resistance of 1000 Ω), which is significantly higher (74%) than that of the control C-MFC1 operated with pure OM and surpasses previously reported performances. Moreover, the physicochemical analysis indicated a C/N ratio of 15–16 in the mature compost, which is ideal for microbial activity. The findings reveal that biocomposting promotes the proliferation of electrogenic bacteria, enhancing microbial biofilm formation and electron transfer efficiency. The dominant bacterial phyla included Actinobacteria, Proteobacteria, and Firmicutes, whose diversity and abundance correlated with improved system performance, as reported in this study. Although the system shows scalability potential, further studies are needed to confirm long-term stability and real-world feasibility under varied environmental conditions. © 2025 Elsevier B.V., All rights reserved.