Two different MFC configurations designed for handling solid wastes as a feedstock were evaluated in batch mode: a single compartment combined membrane-electrodes (SCME) design: and a twin-compartment brush-type anode electrodes (TBE) design (reversed T-shape MFC with two-air cathode) without a proton exchange membrane (PEM). Cattle manure was tested as a model livestock organic solid waste feedstock. Under steady conditions, voltage of 0.38 V was recorded with an external resistance of 470 Omega. When digested anaerobic sludge was used as the seed in the SCME design, a maximum power density of 36.6 mW/m(2) was recorded. When hydrogen-generating bacteria (HGB) were used as the seed used in the TEE design, a higher power density of 67 mW/m(2) was recorded. (C) 2011 Elsevier Ltd. All rights reserved.