Practical increases in power output from soil-based microbial fuel cells under dynamic temperature variations

Soil-based microbial fuel cells (MFCs) are excellent candidates to meet the need for continuous energy sources in low-power and remote sensing applications and to perform useful functions such as soil remediation. Under constant thermal conditions, soil-based MFC performance is known to correlate positively with temperature due to increased bacterial metabolism. Rather than inhibit MFC operation, we show in this work that dynamic thermal conditions can actually strongly improve performance. By varying the temperature cycling times and temperature setpoints in experiments, the average power outputs were increased by 300 to 400%, and current densities were increased by 200%. The same methodology was applied to liquid MFCs but did not show the same intense response.