TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Apparatus: The fuel processing assembly has a maximum production rate of the feed stream, where the selected variable includes the maximum production rate of the feed stream and/or the maximum rated power output of the fuel cell stack and/or the currently available power output of the fuel cell stack.The system further includes a battery bank adapted to store electrical power, and having a maximum stored charge, and variable including the maximum stored charge of the battery bank.The control system includes threshold value(s) for each of the variables.The control system adapted to regulate the rate power is produced by the fuel cell system if one or more of the selected variables exceed the corresponding threshold value(s).The control system is adapted to regulate the rate power production by adjusting the currently available production rate of the feed stream.The system is in communication with one or more facilities adapted to load the system to draw the power from it.The selected variable(s) includes the load including a thermal load, on the system, from one or more facilities.The control system is adapted to regulate the fuel cell system to meet the thermal load.The control system is adapted to limit the power provided by the fuel cell system to prevent the power provided from exceeding a maximum rated power output of the fuel cell stack or a currently available power output of the fuel cell stack.The fuel cell system includes a battery bank including a charge of stored power, regulated to produce power for increasing the charge of stored power when the charge of stored power falls below a selected threshold.The fuel assembly includes processor(s) adapted to produce the feed stream by electrolysis.The fuel assembly is adapted to produce a mixed gas stream from feedstock(s), and fuel processing assembly including a purification region including a membrane including hydrogen selective membrane, in which the mixed gas stream is separated into the feed stream and byproduct stream(s).The load includes a demand for electrical power, preferably demand for heat.Preferred Feed: The feed stream includes hydrogen gas.