A novel approach on the determination of the minimal operating efficiency of a PEM fuel cell

In this article, a novel mathematical approach is proposed to determine the minimal proton exchange membrane fuel cell efficiency below which it is not recommended to operate the fuel cell. The objective of this proposal is to minimize the annual fuel cost and the electricity cost of a proton exchange membrane (PEM) fuel cell since both terms are efficiency dependent. A new concept developed in this article might be used as a valuable mathematical tool to determine the minimal efficiency required to operate a fuel cell in a reasonable fashion in order to make the fuel cell system technically and economically feasible. Two dimensionless mathematical criteria J1 and J2 were proposed for the annual fuel cost and electricity cost, respectively. A minimum fuel cell efficiency of ηmin=37% was obtained with J1 and J2 values of 2.7 and 0.026, respectively.