A number of other metrics have been proposed to measure MFC efficiency and for the comparison
of MFC technology with other organic-matter-to-energy converting technologies. These include
energy-capture efficiency, voltage efficiency, mass-transfer efficiency and process energy efficiency.
Detailed discussions of these metrics are outside the scope of this review. Readers interested in
discussion of MFC efficiency, and comparisons of MFC efficiency with technologies for generating
bioethanol and anaerobic digestion to methane are directed to Rittmann et al. 2008 .