*2.6. Cell and Stack Performance*

What is labeled as the electrical efficiency ηelectric in this work relates to the lower heating value of hydrogen *E*LHV [11]:

$$\begin{aligned} \eta\_{\text{electric}} &= \frac{E\_{\text{cell}}}{E\_{\text{LHV}}}\\ E\_{\text{LHV}} &= 1.254 \text{ V} \end{aligned} \tag{18}$$

and, furthermore, is used to calculate the heat flow . *Q* of the cell/stack based on the power delivered *P*stack. As a simplification, it is assumed that the product water fully evaporates before leaving the cell/stack [11]:

$$
\dot{Q}\_{\text{stack}} = \left(\frac{P\_{\text{stack}}}{\mu\_{\text{electric}}}\right) - P\_{\text{stack}}.\tag{19}
$$
