Solar assisted microbial fuel cells

Microbial Fuel Cells (MFC) use living microbes as biocatalysts and the organic substrates as the fuel to produce electricity, with water as the byproduct. In theory, higher operating temperatures in the anode increase the performance of the MFC, with potential for technology improvement with using solar thermal energy to provide heat to increase the temperature.;The objectives of this study were to find the optimum temperature of operation of an MFC and to design an MFC system using solar thermal energy to sustain the anode compartment of the MFC at the optimum temperature.;Two very long experiments were conducted with a customized MFC with multiple bacteria from local river water and the largest unit known to date. The first experiment was conducted to find the best operating conditions of the MFC at room temperature, while the second experiment utilized the best operating conditions obtained from the first experiment to find the optimum temperature of the MFC.;The optimum temperature of the MFC obtained as the result from this study was in the range of 30-35 °C with a significant increase in the average performance of 3030% comparing to the same operating condition at room temperature. A solar thermal system was designed as the auxiliary energy source integrated to the MFC and was simulated to maintain the temperature of the MFC's anode compartment at the optimum temperature.;Even though the results of this study show an increase in output of a Solar Assisted MFC of two orders of magnitude, the cost of electricity produced from this technology is still orders of magnitude higher than other existing technologies. Nevertheless, this system could be used in remote areas where small amounts of electricity are urgently needed. In the early development stages of MFCs in general, this study provides some key evidence of improving the output through temperature control of the microbes.