Performance evaluation of flexible CIGS modules based on operational data under outdoor conditions

Abstract

Abstract As a major driver to achieve feasible long‐term goals of the Korean Green New Deal policy, a renewable system application in a building, such as the building‐integrated photovoltaics (BIPV) system, has been expedited by raising a BIPV installation subsidy to 70%. Among the technology of BIPV modules, the CuInGaSe2 (CIGS) type module has been drawing attention and considered as one of the effective alternatives because of its benefits, including its flexibility, lightweights, and relative ease to use as a building material. However, the lack of information understanding of its real application to buildings has still existed under various outdoor experimental conditions. In response to this gap, this study analyzed the power generation performance of flexible CIGS modules under outdoor exposure conditions to evaluate their applicability to BIPV buildings. To conduct the test, the CIGS module was installed on an inclined plane (30°) and vertical plane (90°) using a mock‐up installed facing the south. In particular, this study assessed performance ratio (PR) values to analyze the power generation performance behaviors under direct/diffuse irradiance conditions along with diverse cloud cover conditions. Results from this experimental case study indicated that the power generation performance of the vertical CIGS module decreased compared with that of the inclined CIGS module during all analysis periods, except for the February period. This phenomenon became more distinct as the solar altitude angle increased, and the power generation performance of the vertical module became similar to that of the inclined module as the altitude angle decreased. By experimenting with the diffuse irradiance condition depending on the change in cloud cover, the PR decreased by approximately 12%.

Keywords

• building‐integrated photovoltaics (BIPV)
• CuInGaSe2 (CIGS)
• performance ratio
• solar altitude angle