Current wastewater treatment processes require large amount of power for various treatment units and most of the useful energy available in the wastewater remains unrecovered. With increase in demand for clean treatment technologies, Microbial Fuel Cell (MFC) technology is a v iable option for treatment of wastewater, since simultaneous recovery of energy in the form of direct electricity with desired degree of treatment can be achieved in this process. Extensive research on MFCs is going on at laboratory scale but very few pilot scale studies have been reported. An attempt has been made to produce low cost scaled up MFCs fabricated using naturally available cheaper clay material as proton exchange membrane without involving any costly polymer membrane or noble metals for electrode fabrication. The results of the experimental study are promising and encouraging for further scaling up of MFCs. Economic feasibility of MFCs for treating municipal wastewater having COD of 500 mg •L-1 has been studied. The cost analysis shows that clay material may be suitable option as a membrane in scaling up of MFCs. It needs further study on strength of clay material as membrane to handle higher wastewater flows in larger reactor volume. Although, these clay MFCs were operated for more than six months, the life of this material without deteriorating its functional utility also need attention.