Degradation of back surface acrylic mirrors: Implications for low concentration and mirror augmented photovoltaics

Abstract

In developing photovoltaic (PV) technology for widespread adoption, it is crucial to provide PV power with comparable prices to traditional technologies. A method to lower the cost of energy delivered by a PV system is to increase power output. While PV panel costs account for as much as 50% of system costs [1] balance of system (BOS) is among the other major costs associated with PV technologies. Because mounting, wiring, and installation tend to scale with system area, higher efficiency devices will lower these BOS costs. Under this concept, our research group seeks to provide opportunities for lower cost power using flat-panel PV modules augmented through the addition of low cost solar mirrors. Since mirror augmentation costs ~10% of module cost, and increased irradiance scales almost linearly with power production, in order to harvest more incident solar irradiance, an optimized configuration design between flat-panel module and mirror are necessary in this fixed (non-tracked) mirror-augmented photovoltaic (MAPV) system. As with many renewable energy technologies, PV energy generation requires durability of systems, components, and materials for 25 years in order to be economically viable. In order to ensure investors and early adopters that MAPV can fulfill expected service lifetimes of 25+ years durability studies have been performed showing the effects of artificial aging in terms of angle distribution of reflected light and reflectance loss.

Statistical and Domain Analytics Applied to PV Module Lifetime and Degradation Science

“…This lifetime approach must also cross-correlate realworld and accelerated exposures [22]- [24]. We propose and develop a PV module lifetime and degradation science model (PVM L&DS) using an unbiased analytical approach (combined with both sound statistical analysis and proven domain knowledge and refined iteratively with the latest evidence) and encompassing a comprehensive set of degradation pathways aimed at determining the lifetime of current and next generation technologies.…”

BRDF characterization of Al-coated thermoplastic polymer surfaces

“…Moreover, it became obvious from the BRDF data that incident light is reflected within a narrow scattering angle, which brings us to compare the samples with perfect mirrors. These two observations lead us to employ the empirical ABg model, which is widely used in many fields, 22,23 to fit the BRDF data. 24 To analyze the specimens with the ABg model, we switched to the Harvey Shack representation; the most important coordinate in this reference system is |b À b 0 |, which is the difference between the projection of the scattered beam (b = sinh scatter ) and the projection of the specular direction (b 0 = sinh specular ) in the plane of incidence.…”

Degradation pathway models for photovoltaics module lifetime performance

“…This lifetime approach must also cross-correlate real-world and accelerated lab based exposures [9], [10], [11]. An unbiased analytical approach that considers full system level modeling and a comprehensive degradation model, PV module lifetime and degradation science model (PVM L&DS), that is refined iteratively by updated analysis is necessary in order to determine lifetime of current and new technologies.…”