Fuel Cell/Photovoltaic Integrated Power System for a Remote Telecommunications Station

The Schatz Energy Research Center (SERC) has designed, built, and operated a PEM fuel cell power system that supplies back-up power to a remote radio-telephone repeater. The repeater, located within Redwood National Park in northwestern California, is part of the Yurok Indian Reservation’s telecommunications system. A photovoltaic (PV) system with batteries provides primary power for the repeater. When solar insolation is insufficient to maintain battery state-ofcharge, the 100-Watt fuel cell system starts automatically and provides clean, quiet, reliable power. The system began unattended operation in November 1999. The original fuel cell stack logged 3239 hours of run time. In January 2001, SERC engineers refurbished the original fuel cell stack, incorporating improved membrane-electrode assemblies and gas diffusion media. The original resin-impregnated graphite was replaced with pyrosealed components and a temperaturecontrolled fan switch was added to protect the stack from sudden temperature increases while minimizing parasitic loads. The system ran continuously though October 2001, accumulating 3836 hours of run time and completing 283 start-stop cycles. The system and the original stack are described in detail in two earlier papers [1,2]. This paper will focus on the performance of the second stack used in the system.