Stability testing of CdTe/CdS thin-film photovoltaic modules

High efficiency, durability, and long-term stability are critical components of cost-effective photovoltaic modules. Industry-established protocols for testing efficiency and durability such as ASTM E948, E1036, and the Module Qualification Test, are effective in ensuring the initial module performance and the integrity of the encapsulation and mechanical components. However, these protocols do not adequately test long-term module performance. This paper describes the initial development of an accelerated testing methodology utilizing various applied stresses. The results of more than 2 years of indoor testing indicate that stable CdS/CdTe modules can be produced.