John Sherwin

Survey of potential-induced degradation in thin-film modules

Abstract. Two CdTe and two copper indium gallium (di)selenide (CIGS)-type modules were tested for potential-induced degradation (PID) with positive and negative 1000 V biases applied to the active cell circuit in an 85°C, 85% relative humidity environmental chamber. Various degradation mechanisms could be seen with signatures such as shunting, transparent conductive oxide (TCO) corrosion, charge carrier lifetime reduction, and dead active layer at edges along with resulting cell mismatch. All modules tested exhibited degradation by system voltage stress in chamber, but only one module type has degraded in parallel field tests. I−V curve data indicated that one CdTe-type module sequentially exhibited shunting followed by a recovery and then series resistance losses. This module type showed TCO delamination from the glass in the environmental chamber tests and also exhibited power degradation within 5 weeks in field tests. Relative rates of Coulomb transfer from the voltage-biased active cell circuit to ground are compared for the modules in chamber tests to those placed outdoors under system voltage stress to extrapolate the anticipated time to failure in the field. This analysis correctly indicated which module type failed in the field first.

Building America Industrialized Housing Partnership (BAIHP II)

This report summarizes the work conducted by the Building America Industrialized Housing Partnership (BAIHP - www.baihp.org) during the final budget period (BP5) of our contract, January 1, 2010 to November 30, 2010. Highlights from the four previous budget periods are included for context. BAIHP is led by the Florida Solar Energy Center (FSEC) of the University of Central Florida. With over 50 Industry Partners including factory and site builders, work in BP5 was performed in six tasks areas: Building America System Research Management, Documentation and Technical Support; System Performance Evaluations; Prototype House Evaluations; Initial Community Scale Evaluations; Project Closeout, Final Review of BA Communities; and Other Research Activities.