What advancements have been made in the testing and modeling of bifacial solar panels

Testing Advancements

• Field Data and Energy Gains:
  Multi-year studies, such as one by the National Renewable Energy Laboratory (NREL), have empirically demonstrated up to a 9% increase in energy production from bifacial panels compared to traditional monofacial modules under real-world conditions. This data helps validate and refine predictive models for bifacial systems.
• I-V Curve Testing Enhancements:
  Advanced I-V curve measurement tools, like Fluke’s SMFT-1000 and PVA-1500, capture critical parameters such as tilt angle, module temperature, and frontside irradiance, enabling accurate translation of field performance into standardized test conditions. These tests help detect underperforming modules, accounting for bifacial gains that standard conditions do not capture, thus optimizing maintenance and installation strategies.
• Capacity Testing and Standards Development:
  Researchers are developing capacity tests specific to bifacial modules that incorporate backside irradiance and increased electrical currents. This is crucial for updating industry standards, safety regulations, and ensuring proper sizing of system components like conductors and fuses to handle the higher outputs of bifacial panels.

Modeling Advancements

• Backwards Ray-Tracing Simulation:
  Sophisticated simulation approaches, such as backwards ray-tracing, model how photons interact with complex environments and panel geometries. This allows evaluation of bifacial panel performance in the presence of topographical variations, structures (e.g., carports, canopies), and dynamic shading scenarios, improving system design accuracy prior to installation.
• Bifacial Tracking Systems Modeling:
  Integration of bifacial modules with tracking systems (single-axis and dual-axis) has been extensively studied. Modeling efforts include simulations of tracker designs, backtracking algorithms to reduce shading, and the impact of albedo enhancement on energy yield. A recent IEA PVPS Task 13 study compared multiple predictive models to improve accuracy and provide best practices for bifacial tracking system optimization.
• Market and Design Simulation:
  Forecasting models predict bifacial modules will capture 50-60% of global PV market share by 2029, driven by improved glass-glass or transparent backsheet designs, higher cell efficiencies, and advanced encapsulants like polyolefins that reduce degradation. Modeling weighs trade-offs between durability, cost, and energy yield to aid manufacturers in design optimization.

Material and Design-Driven Testing Impacts

• Encapsulant and Backsheet Innovations:
  Testing protocols now consider the effects of new encapsulants (POE vs EVA) that improve reliability and reduce degradation in bifacial modules. Manufacturers also test the trade-offs of glass-glass versus transparent Tedlar backsheets regarding transparency, durability, weight, and warranty impacts.
• Durability and Damage Assessment:
  Ongoing studies evaluate how physical damage such as cracked cells from shipment affect module reliability and performance over time, particularly when used with tracking systems. This informs maintenance protocols and warranty standards.

Summary:

The latest advancements in bifacial solar panel testing and modeling encompass extensive field data collection, enhanced I-V curve diagnostics, and sophisticated simulation tools that account for environmental and system-level complexities. These improvements allow for more precise energy yield prediction, performance optimization with tracking systems, and informed material and design choices supporting durability and cost-efficiency. Emerging standards and testing methods are evolving to reflect the unique characteristics of bifacial technology, paving the way for broader commercial adoption and integration into utility-scale solar markets.