Long-term stability performance testing of amorphous silicon modules under natural sunlight

A major task of the PV Module Testing and Performance Group at SERI is to develop and coordinate the implementation of standard test procedures and instrumentation for monitoring and analyzing PV submodules and modules for determining the outdoor performance, stability, reliability, and energy output of thin-film PV devices. Through outdoor testing, researchers can identify performance issues that will require further laboratory investigation in support of flat-plate, thin-film collector research and development. To accomplish this, the SERI outdoor PV test facility was established in 1982 in Golden, Colorado. The group has designed testing systems and analysis procedures for numerous thin-film modules and submodules, and has tested them both indoors (under simulator) and outdoors. Long-term outdoor stability tests have been conducted specifically on amorphous silicon thin-film submodules and modules. Cooperative test programs have been established with private US amorphous silicon PV module manufacturers and SERI amorphous silicon subcontractors for short- and long-term outdoor stability and performance testing of submodules, prototype modules, and commercially available modules at SERI's outdoor test facility. Selected test results based on long-term stability performance testing over the past two years are presented