Microbial fuel cells (MFCs) represent a completely new method of renewable energy recovery. The purpose of this work is to study the effect of biometric flow channels on the power performance in the single rumen microbial fuel cells (RMFCs) at different Reynolds numbers. Experiments in a circulation system were executed by using a double two-inlet Y-type inlet channel and connecting it with the RMFCs. Some results that were found from the numerical simulation and experiment are addressed as follows: First, the biometric flow channel would create a more uniform flow field with obstacles than one without, regardless of the Reynolds number. Second, an extra voltage output of 0.2 V, based on the example without obstacles, was provided as in the case of one with. This further explains the design of biometric flow channels having a greater, more positive effect on power performance. Finally, these observations can provide more information on realizing the mechanism of MFCs dynamic reactions and further enhance power performance. Copyright (c) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.