This paper reports on the development of key components, specifications, configuration and operation characteristics of a 5 kW H-2/air proton exchange membrane fuel cell (PEMFC) system for stationary power. A 5 kW class PEMFC module operating on a membrane humidifying method was developed for stationary power applications. The stationary system can supply full power within 1 min from startup, and offers a high-power generation efficiency of 30% or higher in overall output range, yielding good-quality electrical power with little noise. (c) 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All fights reserved.