A parametric study of fuel cell system efficiency under full and part load operation

Fuel cell technology is an emerging, environmentally friendly energy conversion technology for use in mobile and stationary applications. A contribution to the understanding of fuel cell system efficiency and operation under full and part load is presented in this paper. An analytical, three-parameter model, independent of specific fuel cell system, is developed and important performance parameters defined and discussed. Three useful properties of fuel cells are documented: (i) their ability to produce electric energy with constant — or even increased — efficiency at reduced power (enhanced part power efficiency), (ii) their ability to respond instantaneously to changes in power delivery demands (instantaneous load-following properties), and (iii) their theoretical ability to deliver an exhaust gas consisting of almost pure CO2 (intrinsic CO2 separation).