The chemical energy contained in urine can be efficiently extracted into direct electricity by Microbial Fuel Cell stacks to reach usable power levels for practical implementation and a decentralised power source in remote locations. Herein, a novel type of the anode electrode was developed using powdered activated carbon (PAC) applied onto the carbon fibre scaffold in the ceramic MFC stack to achieve superior electrochemical performance during 500 days of operation. The stack equipped with modified anodes (MF-CV) produced up to 37.9 mW (21.1 W m−3) in comparison to the control (CV) that reached 21.4 mW (11.9 W m−3) showing 77% increase in power production. The novel combination of highly porous activated carbon particles applied onto the conductive network of carbon fibres promoted simultaneously electrocatalytic activity and increased surface area, resulting in excellent power output from the MFC stack as well as higher treatment rate. Considering the low cost and simplicity of the material preparation, as well as the outstanding electrochemical activity during long term operation, the resulting modification provides a promising anode electrocatalyst for high-performance MFC stacks to enhance urine and waste treatment for the purpose of future scale-up and technology implementation as an applied off-grid energy source.