Short-Term Measurement of a Photovoltaic/Fuel Cell Remote Hybrid Power System at Golden Gate National Recreation Area

Abstract

This paper reports short-term performance measurement of a hybrid photovoltaic/fuel cell power supply system at Kirby Cove Campground in Golden Gate National Recreation Area, California. The system operated reliably for two years from June 1999 to July 2001. During this period, the campground host load was met with a combination of solar power and power from the fuel cell. In August of 2001, reports of power outages justified an in-depth investigation. Data is reported over 13.5 days from September 2 to September 15, 2001. Over this period, energy delivered by the photovoltaic array totaled 42.82 kWh. Energy delivered by the fuel cell totaled 1.34 kWh, and net (out-in) energy from the battery totaled 6.82 kWh. After losses in the battery and inverter, energy delivered to the campground host totaled 34.94 kWh, an average of 2.6 kWh/day. Photovoltaic efficiency was measured at 8.9%. Fuel cell efficiency was measured at 42%, which is a typical value, but fuel cell power output was only 35 W instead of the 250 W rated power. Replacing a burnt fuse restored fuel cell power to 125 W, but several cells measured low voltage, and the fuel cell was removed for repair or replacement. Ordinarily, load in excess of the PV capability would be met by the fuel cell, and 22 cylinders of H2 (261 scf, 7,386 sl each) were consumed from April to August 2001. After failure of the fuel cell, load in excess of the solar capability resulted in discharged batteries and eight power outages totaling 48 hours in duration. Thus, overall system availability was 85% when relying only on solar power. This paper describes daily system operation in detail, presents component performance indicators, identifies causes of performance degradation, and provides recommendations for improvement.