Key challenges in accurately simulating the performance of bifacial solar panels stem from the many complex variables affecting their rear-side energy production, measurement difficulties, and modeling uncertainties. The main challenges include:
1. Complexity of Rear-Side Irradiance and Environment Variables
- Bifacial panels generate electricity from both front and rear sides, where rear-side production depends heavily on site-specific factors such as ground albedo (reflectivity), shading, module temperature, ground cover, and even topography. These factors vary spatially and temporally, making accurate modeling difficult.
- Variations in irradiance type—direct versus diffuse sunlight—also affect rear-side output, complicating the irradiance input needed for simulations.
2. Measurement and Monitoring Challenges
- Measuring the actual performance of bifacial panels is complicated due to shading on the rear surface from sensors and mounting structures, which can interfere with accurate temperature and irradiance readings.
- Traditional back-of-module temperature sensors can shade cells and provide inaccurate readings, so specialized sensors with minimal shading and improved thermal coupling are needed to improve measurement quality.
3. Modeling and Simulation Limitations
- Simulation tools often struggle with accurately accounting for partial shading effects and view factors (the fraction of reflected radiation reaching the rear side), especially in complex installation layouts such as rooftops or uneven terrain.
- Many bifacial modeling approaches assume ideal or simplified geometries (like unlimited sheds or trackers), which may not reflect real-world conditions, resulting in significant uncertainty in predicting bifacial gain and shading losses.
- The availability of detailed irradiance and geospatial data has improved simulations but still cannot fully eliminate uncertainties.
4. Financial and Risk Assessment Implications
- Due to the uncertainties in accurately predicting rear-side production and associated installation costs, investors and lenders often discount the projected bifacial gains, thereby complicating financing for bifacial projects and increasing levelized cost of electricity (LCOE).
5. Reliability and Degradation Issues Affecting Performance Forecast
- Bifacial panels can be more susceptible to certain degradation mechanisms such as potential-induced degradation (PID), which directly impacts performance over time and complicates long-term yield predictions.
- The complex interaction between front and rear sides during degradation further complicates modeling accurate lifespan and financial returns.
In summary, the key challenges to accurate bifacial solar panel performance simulation are intricately linked to:
- Capturing variable environmental inputs like albedo, shading, and irradiance type;
- Measuring rear-side performance without disturbing the system;
- Overcoming limitations in current modeling tools to handle complex geometries and shading;
- Incorporating degradation and reliability factors that impact long-term output; and
- Translating these technical uncertainties into reliable financial models for project viability.
Ongoing improvements in data collection, sensor design, modeling sophistication, and reliability testing are gradually addressing these challenges to better optimize bifacial solar installations.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-are-the-key-challenges-in-accurately-simulating-the-performance-of-bifacial-solar-panels/
