LSA feld test annual report, August 1979-August 1980

Technical Report · Tue Dec 30 00:00:00 EST 1980

DOI:https://doi.org/10.2172/6668162· OSTI ID:6668162

Jaffe, P

After almost four years of endurance testing of photovoltaic modules, no fundamental life-limiting mechanisms have been identified that could prevent the twenty-year life goal from being met. The endurance data show a continual decline in the failure rate with each new large-scale procurement. Cracked cells and broken interconnects continue to be the principal causes of failure. Although the modules are more adversely affected physically by hot, humid environments than by cool or dry environments, there are insufficient data to correlate failures with environment. There is little connection between the outward physical condition of a module and changes in its electrical performance. Electrical degradation is a transient condition that is generally intermittent and is present before a module destined to fail finally fails. Analysis of year-long electrical performance data indicates that the fill factor is insensitive to most measurement problems and remains the best diagnostic tool for determining module degradation. Investigations at the JPL site reveal that shadowing the indirect component of irradiance can reduce the electrical output of modules and result in anomalous performance data. Extrapolating this result to arrays suggests that a loss of power can result if indirect shadowing is not considered in the array layout. The introduction of the Portable I-V Data Logger was a success. About 1200 high quality I-V curves were obtained during a tour of the 15 remote sites. Next year a major reorganization in the inventory of test modules is planned. A significant portion of the older modules will be removed and replaced with modules from the upcoming Block IV large-scale procurement.

• Research Organization: California Institute of Technology (CalTech), Pasadena, CA (United States). Jet Propulsion Lab. (JPL)
• DOE Contract Number: AI01-76ET20356
• OSTI ID: 6668162
• Report Number(s): DOE/JPL-1012-52
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
SOLAR CELL ARRAYS
FIELD TESTS
CONNECTORS
DATA
DATA ACQUISITION
DATA ACQUISITION SYSTEMS
ELECTRICAL PROPERTIES
FAILURES
FILL FACTORS
FRACTURES
HUMIDITY
INSPECTION
PERFORMANCE
PERFORMANCE TESTING
SERVICE LIFE
SHADING
SOLAR CELLS
TABLES
THERMAL DEGRADATION
WEATHER
WEATHERING
CONDUCTOR DEVICES
DIRECT ENERGY CONVERTERS
ELECTRICAL EQUIPMENT
EQUIPMENT
INFORMATION
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SOLAR EQUIPMENT
TESTING
140501* - Solar Energy Conversion- Photovoltaic Conversion
140600 - Solar Energy- Photovoltaic Power Systems