  The intermittency of solar and wind power can be addressed by integrating
them with Solid Oxide Cells (SOCs). This study delves into the transient
characteristics of SOCs and their dependence on dynamic heat and mass transfer
processes. Non-dimensional analysis was used to identify influential
parameters, followed by a 3-D numerical simulation-based parametric analysis to
examine the dynamic gaseous and thermal responses of SOCs with varying
dimensions, material properties, and operating conditions. For the first time,
we proposed characteristic times to describe the relationship between SOC
transients and multiple parameters. These characteristic times represent the
overall heat and mass transfer rats in SOCs. Their effectiveness was validated
against literature and demonstrated potential in characterizing the transient
characteristics of other electrochemical cells. Besides, two examples are
provided to illustrate how the characteristic times facilitate SOC design and
control at minimal computational cost.
