An alternative answer to the vital issues of power production and wastewater treatment leads to the application of microbial fuel cells. These present cells were constructed from cheap Mfensi clay as ion exchange partition and anode chamber. The performance of the cells has no significant variations in relation to their volumes. Experimental results showed that the maximum power densities of 69 mW/m2 and 55 mW/m2 were obtained for Pot1 and Pot2 at 1000 Ω load respectively.