The ability of cyanobacteria to transport electrons to their extracellular environment (termed exoelectrogenic activity) has been exploited to construct biophotovoltaic devices capable Of solar power generation. However, a limited understanding of the biological processes underlying this activity prevent genetic engineering of highly exoelectrogenic strains of cyanobacteria which would boost the power densities produced by these devices. This project aims to identify genes whose products enhance or inhibit exoelectrogenic activity and use this information to engineer a highly exoelectrogenic cyanobacterial strain. sgRNA libraries will be used to generate single-gene knockdown libraries of mutant cyanobacteria using CRISPRi. The exoelectrogenic activity of library members will be screened using a custom electrode microarray. Following this, a general-purpose CRISPR-Cas9 vector will be developed to facilitate genome editing of cyanobacteria to produce a highly exoelectrogenic strain.