Microbial fuel cells (MFCs) have been promising renewable power sources for more than 100 years. In 1911, the occurrence of an electromotive force between electrodes immersed in bacterial or yeast cultures and in a sterile medium with a battery-type setup was reported by Michael C. Potter [1], and it was concluded that electric energy could be liberated from the microbial disintegration of organic compounds. Twenty years later, Cohen [2] conrmed these results and reported a stacked bacterial fuel cell with a voltage of 35 V at a current of 0.2 mA. Although these publications may be considered as the birth of MFCs, the early resonance was doubtful. The rapid advances in other energy technologies like photovoltaic and later also the low prices for mineral oil again led to decreased interest in MFCs. In the 1980s, a slow interest in MFCs came back again [3,4]. Wilkinson [5] proposed the application of MFCs to power self-sustaining (eating) robots. Due to the limitations, including low performance, poor practicability, sustainability, and no application focus, the actual MFC development stagnated at a comparatively low publication level until the turn of the century [6], when the growing awareness of upcoming climate changes and resource depletion fuels environmental concerns to recover energy from organic waste for saving energy and reducing CO2 emissions, MFCs have come to a new stage of development. The technology is no longer considered as a scientic peculiarity and insignicant issue but a serious and important research subject.