BACKFLIP: Determination of Backsheet Material Properties

DuraMAT is comparing market-benchmark technologies to novel non-fluoro-based, co-extruded backsheet materials and their correlation and impact on photovoltaic (PV) module degradation rate. This includes: 

  • Understanding the role of backsheets in the PV module lifetime and their impact on energy yield.
  • Studying a variety of co-extruded, fluorine-free backsheet materials, in direct comparison to market-benchmark backsheets: as is, artificially weathered, and when utilized outdoors in a PV module.
  • Evaluating the degradation behavior of these backsheets and derive parametrized equation(s) that describe degradation rates to predict useful material lifetime. 

Materials

  • Backsheet development (Endurans Solar, formerly DSM Advanced Solar)
  • Polymer expertise on structure-property relations (Endurans Solar) 

Advanced Characterization and Forensics

  • SLAC National Accelerator Laboratory (DSC, WAXS/SAXS chemical and structural analysis)
  • National Renewable Energy Laboratory (NREL) (IV, EL, FTIR, VBD) 
  • Sandia National Laboratories (FTIR, IV, EL) 

Module Testing

  • Module performance and failure mode analysis at NREL
  • Accelerated testing in hydrolytic and photolytic chambers at NREL 

Field Deployment

  • Mini-modules and backsheet samples field exposure at Sandia (BSk Köppen-Geiger climate) and University of Florida (Cfa) sites

Techno-Economic Analysis

  • Correlation between indoor accelerated aging tests and long-term outdoor exposures in different climates

Core Objective

Module Material Solutions

Location

SLAC, Sandia, NREL, and Endurans Solar

Applications

Through its work, BACKFLIP anticipates to primarily impact three distinct applications. Research institutes would secure progress beyond the state of the art in understanding of module failure and degradation-modes, as well as in predicting the service life of backsheets. Backsheet manufactures will improve backsheet performance and reliability, enabling better differentiation and product positioning. Developers and financing institutions will benefit from lower financing costs and no long-term liabilities from toxic and non-recyclable assets. 

Availability

PV industry players, certification bodies, financing institutions, and research institutes across the globe.

References

Nicola Sicchieri, Laura T. Schelhas, Sona Ulicna, Bruce King, Ashley Maes, David C. Miller, Nicola Sicchieri, Kurt van Durme, Nicoleta Voicu, Peter Pasmans, Rob Janssen, "BACKFLIP:Determination of backsheet material properties. A comparison of market-benchmark BACKsheet technologies to novel non-FLuoro-based co-extruded backsheet materials and their correlation and ImPact on PV module degradation rates", Proc DuraMAT Autumn Work., 2020. 
 
Milica Mrcarica, Frederic Dross, David C. Miller, Laura T. Schelhas, Bruce H. King, Xiaohong Gu, John Sherwin, "Determination of BACKsheet material properties: a comparison of market-benchmark technologies to novel non-FLuoro-based co-extruded backsheet materials and their correlation and ImPact on PV module degradation rates", Proc DuraMAT Autumn Work., 2019.

DuraMAT Autumn Virtual Workshop, 23rd September 2020: A comparison of market-benchmark BACKsheet technologies to novel non-FLuoro-based co-extruded backsheet materials and their correlation and ImPact on PV module degradation rates, Nicola Sicchieri. 
 
DuraMAT TechTalk, webinar, 3rd of August 2020: Material properties, Laura Schelhas and Michael Thuis. 

Contact

To learn more about this project, contact Kurt van Durme or David Miller.

Figure 1. Local shading detection in a time series of global horizontal irradiance (left) and street view of instrument location (right).

Chart showing Axial Strain - Video Extensometer (mm/mm) on the x-axis and Tensile Stress (Mpa) on the y-axis.

Figure 1. Local shading detection in a time series of global horizontal irradiance (left) and street view of instrument location (right).