Compared to microbial fuel cells, which use heterotrophic microorganisms, biological photovoltaic systems need no input of organic compounds to supply reducing equivalents to the system. This improves the efficiency of light-to-electricity conversion by minimising the number of reactions separating the capture of light energy and reduction of the anode. A disadvantage of using oxygenic photosynthetic material in bioelectrochemical systems is that the production of oxygen in the anodic chamber has a detrimental effect on the cell voltage.