In principle, O2 is generated from H2O in the photosystem in the anodic half-cell. Therefore, this cell may be an ideal device converting the light energy into the electric energy with no special chemical fuel and no product. However, the power is not enough for practical use at the present stage, and unfortunately the cell performance is inferior to the best one of the prototype photosynthetic bioelectrochemical cells, although the prototype cell utilizes ferricyanide as a cathodic (oxidizing) fuel