Plant microbial fuel cells from the perspective of photovoltaics: Efficiency, power, and applications

The plant microbial fuel cell is a fascinating technology that combines plants and bacteria to produce electricity. As sunlight is converted into electric power, plant microbial fuel cells can be compared to photovoltaics on various levels. To investigate to what extent this comparison goes up, a rough upper limit for the energy conversion efficiency of plant microbial fuel cells was calculated and compared to various photovoltaic classes. By examining each step in the process, with the accompanying losses, the maximum power conversion efficiency of a plant microbial fuel cell was estimated to be around 0.92%. Although this efficiency is relatively low, the plant microbial fuel cell does have attractive features making them more interesting than photovoltaics, such as price, simplicity, self-sustainability, working during the night, etc. Moreover, a unique feature is that plant microbial fuel cells can be used as low-power environmental sensors and for environmental remediation. These multidisciplinary features account for the unique place the plant microbial fuel cell currently has in the world of environmental, renewable – and particularly solar – energy research.