This chapter reviews microbial fuel cells (MFCs) for transforming organic solid waste into renewable energy using microbially formed anodes, cathodes, and membranes. It covers materials derived from microbial and bioelectrochemical processes, including metals, metal oxides, and nonmetals, highlighting their use in electricity generation, wastewater recycling, and nanomaterial applications. MFCs offer cost-effective, sustainable energy production, leveraging biofilms, microbial lysis, and electrochemical reactions for industrial and environmental applications.