TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred System: The system further comprises an expander coupled to a compressor. It further comprises a first exhaust stream conduit in fluid communication between the moisture-laden exhaust outlet and the condensation side and a second exhaust stream conduit in fluid communication with the moisture-laden exhaust outlet, where during the operation mode, the controller actuates some of the valves to place the second exhaust stream conduit in fluid communication between the moisture-laden exhaust outlet and the expander; and during the startup/shutdown mode, the controller actuates at least some of the valves to vent the second exhaust stream conduit. The membrane-based humidifier is a hollow fiber membrane-based humidifier. It preferably permeates oxygen (O2) over nitrogen (N2). Preferred Method: Operating the fuel cell system further comprises: (i) providing a compressor coupled to an expander; (ii) compressing the humidified feed with the compressor before the humidified feed is directed to the cathode side; and (iii) expanding the dried exhaust stream with the expander before the dried exhaust stream is vented to produce energy, where the energy is transferred to the compressor. The moisture-laden exhaust stream is split into first and second moisture-laden exhaust streams and the first moisture-laden exhaust stream is directed to the fuel cell in the step of directing the moisture-laden exhaust stream from the fuel cell; and the second moisture-laden exhaust stream is vented and also expanded by the expander. The method further comprises: (i) discontinuing the directing of the dry air feed to the evaporation side thus preventing humidification of the dry air feed at the evaporation side; (ii) discontinuing the directing of the hydrogen from the source of compressed hydrogen to the anode side; (iii) discontinuing the venting of the dried exhaust stream; (iv) directing the dry air feed to the cathode side; (v) directing a first portion of the dried exhaust stream to the evaporation side to sweep moisture from it and venting the combined moisture and dried exhaust stream; and (vi) directing a second portion of the dried exhaust stream to the anode side. It further comprises: (i) providing a compressor coupled to an expander; (ii) compressing the dry air feed with the compressor before the dry air feed is directed to the cathode side; and (iii) expanding the second portion of the dried exhaust stream with the expander before the second portion of the dried exhaust stream is directed to the anode side thus producing energy, where the energy is transferred to the compressor.