Performance of photosynthetic electrochemical cells using immobilized Anabaena variabilis M-3 in discharge/culture cycles

The performance of photosynthetic electrochemical cells using Anabaena variabilis M-3 immobilized within alginate beads was investigated during repeated discharge and culture cycles of 10-h each. The effect of the light intensity during the culture periods on the duration of the current output and the recovery of endogenous total sugar in the Anabaena cells was examined. Compared with continuous discharge operation, the duration of the current output was extenced by 10 times when the electrochemical cell was operated under 10-h discharge (dark)/culture (light) cycles with a light intensity of 100 W/m² during the culture periods. The conversion efficiency of light energy into electricity was about 0.2% under these conditions.