Our short paper titled Farming Electrons: Galvanic vs. Microbial Energy in Soil Batteries has been accepted to IEEE Sensors Letters.
Recent work shows the exciting potential for soil microbes as a renewable energy harvesting source. However, the choice of materials in microbial fuel cells (MFCs) significantly impacts where the energy comes from. MFCs with metallic anodes draw energy from both renewable bacterial activity and non-renewable galvanic corrosion of cell components. Previous studies do not analyze these two power sources separately. This letter clarifies the behavior of metallic MFCs by characterizing galvanic activity separately from biological activity. We find that the majority of energy attained from prior designs is most likely galvanic, not bacterial, and as a consequence is non-renewable.