The present invention provides an apparatus and methods for variably supplying power from a stand-alone fuel 
cell power supply 
system including a power conversion unit, a 
power switching unit and a load 
control unit. Preferably, a controller manages 
system configuration to switch the loads, the power conversion and the delivery between the two without 
reducing capacity by redundantly backing up each individual portion with a 
bank of at least two modules for each unit. Preferably, controller actuated devices are triggered automatically in response to monitors that sense performance operating parameters and detect values operating outside a threshold range. Preferably, each of the units and the components in each unit are banked in a plurality of modular units so that individual 
converters may be interchanged, individual 
fuel cells may be interchanged, individual controllers may be interchanged, and individual storage units such as batteries may be interchanged to ensure proper operation of each 
bank despite changes or failures in individual components of the 
bank. The power 
system may include couplers for connecting the system to dedicated outlets such as an NEC standard 120 / 240 
volt building circuitry. The invention monitors multiple elements from 
fuel supply, 
fuel cells, 
converters, storage units, and controls as well as the loads for balanced, reliably robust, high 
power quality, and independent power supply.