As an electrochemical cell stack gets older the internal resistances
within the stack rise overtime as the materials that the stack is made of
degrade. Consequently, an old and "worn" electrochemical cell stack draws
less current at the same stack voltage and operating temperature as a new
stack. When the current draw falls the electrochemical reaction rates
also fall, as less energy is available to drive the electrochemical
reactions. However, if the operating temperature of an older stack is
controllable raised the current draw by an electrolyzer cell stack also
rises, which in turn causes the reaction rates to rise again.
Accordingly, in some embodiments, a balance-of-plant system is operable
to regulate the current draw of an electrolyzer cell stack by first
manipulating the operating temperature of the same electrolyzer cell
stack.