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Thermal-Mechanical-Electrical Model for PV Module-Level Failure Mechanisms

DuraMAT's thermal-mechanical-electrical model simulates how photovoltaic (PV) module deployment environments induce the damaging thermal and mechanical stresses leading to module degradation via delamination, cell fracture, solder bond fatigue, and other mechanisms.

The module-scale model will capture key degradation physics at the length- and time- scales of interest. It's tightly coupled with experimental material and module characterization efforts to receive information for model inputs and validation while enriching interpretation of measurement results.

Currently, we've developed proof-of-concept models that accept direct environmental loads on a full-size module including:

  • Wind pressure
  • Temperature changes
  • Rack mounting constraints
  • Gravity.

We can couple cell-scale sub-models to full module results for resolving detailed mechanisms including interconnect thermal-mechanical fatigue and delamination stresses. Additionally, we're developing coupled electrical models to predict thermal loads and hotspot effects in operational modules. All models may be utilized parametrically for optimization, uncertainty quantification, and sensitivity studies.

This final validated and informed modeling capability will enable more accurate lifetime predictions and more representative accelerated test specifications. It will also allow for optimized module material selection and design for durability.

Primary Capability Area

Predictive Simulation

Location

Sandia National Laboratories (SNL)

Applications

  • Prediction of key high-stress areas of interest to monitor for damage in as-deployed modules
  • Design trade studies to minimize susceptibility of components to fatigue damage
  • Assessment of accelerated mechanical testing for field representativeness
  • Prediction of module operating temperatures

Availability

This capability is available to SNL scientists and external collaborators.

References

Hartley, J. Y.; Roberts, S. A.; Bosco, N.; Schelhas, L. (2018). “Thermal-mechanical modeling of PV modules and components.” Photovoltaic Reliability Workshop, Lakewood, CO.

Hartley, J.Y.; Roberts, S. A. (2018) “Effects of Solar Cell Materials and Geometries on Thermally Induced Interfacial Stresses.”45th IEEE Photovoltaics Specialists Conference, Waikoloa, HI.

Contact

To learn more about the thermal-mechanical-electrical model capability, contact James Hartley.

Yellow, rectangular image with a green grid showing hotspots in red. "Fixed" with arrows pointing at four locations on the long sides. Three questions surround the image: "Is testing a 2x2 cell mini-module representative?" "Are cell stresses symmetric?" "What cell positions see the most stress, under what loads?"