A new 2 l scale microbial fuel cell (MFC) configuration was developed to generate bioelectricity from particulate substrates. Voltage and power densities generated in this MFC fed with sucrose, particulate cattle manure, and manure wash-water as the substrates were evaluated in batch mode, with and without external mediators. Voltages averaged 0.5 V in open circuit, and 0.4 V under a resistive load of 470 Omega. Power densities (67 to 215 mW/m(2)) were comparable to previous work that had used liquid wastes as substrates. Based on the energy yield per unit mass of feedstock (similar to 10 kJ/kg wet manure), cattle manure has limited potential to serve as a feedstock for electricity production via MFCs.