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| Boost Solar Energy Yield with Artificial Ground Reflector ( Bifacial PV Systems ) |
This research (conducted by scholars from the University of Ottawa and the National Renewable Energy Laboratory (NREL)) examines the influence of artificial ground reflectors on the energy yield and economic feasibility of single-axis-tracked bifacial photovoltaic (PV) systems. The study integrates field experiments with ray-tracing modeling to assess how factors such as reflector size, placement and material characteristics impact system performance. However, the complexities involved in these variables may pose challenges. Although the findings are promising, they also suggest that further investigation is necessary because the results could vary under different environmental conditions. This approach aims to provide a comprehensive understanding of the dynamics at play.
The study, titled "Effects of Ground Reflector Size and Position on the Energy Yield and Economics of Single-Axis Tracked Bifacial Photovoltaic Systems," was published in the prestigious journal Progress in Photovoltaics.
Integrating artificial ground reflectors into solar equipment can increase energy production and efficiency. This research will contribute to the global transition to zero-emission energy.
1. Introduction to Artificial Ground Reflectors in Solar Energy
Solar energy is rapidly evolving, and bifacial photovoltaic (PV) systems are at the forefront of this transformation. Unlike traditional monofacial panels, bifacial modules capture sunlight on both sides, significantly boosting energy output. However, the performance of bifacial systems heavily depends on the ground albedo (reflectivity). Enter artificial ground reflectors—a game-changing solution to enhance energy yield, especially in areas with low natural ground reflectivity.
In this blog, we will investigate the ways in which artificial ground reflectors can enhance the efficiency of single-axis-tracked bifacial PV systems. Our focus will be on several key aspects: the optimal size, strategic placement and the associated economic benefits. However, it is essential to consider these factors together, as they can significantly influence overall performance. Although the initial investment may seem high, the long-term savings (and advantages) typically justify the costs. This analysis aims to provide a comprehensive understanding of the subject, helping readers to appreciate the potential of such innovations in renewable energy.
2. What Are Artificial Ground Reflectors?
Artificial ground reflectors are high-albedo materials, such as mirrors, white tarps, or specialized geomembranes, placed beneath solar panels to increase the amount of light reflected onto the rear side of bifacial modules. These reflectors can significantly enhance the energy yield of bifacial systems, especially in regions with low natural ground reflectivity.
3. How Do Reflectors Improve Bifacial Solar Performance?
Bifacial solar panels generate electricity from both the front and rear sides. The rear side captures reflected light from the ground, making ground albedo a critical factor. Artificial reflectors with 70% reflectivity can increase rear irradiance by up to 209.9%, leading to a 6.2% boost in daily energy yield compared to natural ground cover.
4. Optimal Reflector Size and Placement
The size and placement of artificial reflectors play a crucial role in maximizing energy gains. Here’s what the research shows:
4.1 Ideal Placement:
- Reflectors should be placed directly underneath the module to maximize rear irradiance and minimize shading.
- For single-axis-tracked systems, the optimal position is centered under the torque tube, where the reflector can capture and reflect the most sunlight.
4.2 Reflector Size:
- Larger reflectors (up to 550 cm) provide the highest energy gains, increasing annual energy yield by up to 4.5%.
- Smaller reflectors (150 cm) still offer benefits but are more sensitive to placement, with energy gains ranging from 0.9% to 1.6%.
5. Economic Benefits of Artificial Reflectors
The economic viability of artificial reflectors depends on their cost-effectiveness and the energy yield improvements they provide. Here’s what you need to know:
5.1 Breakeven Installed Cost:
- In Golden, Colorado, the breakeven installed cost for reflectors ranges from 2.50 to 4.60/m², depending on size and placement.
- In cloudier regions like Seattle, Washington, the breakeven cost can reach $6.00/m², making reflectors more economically viable in areas with higher diffuse irradiance and lower energy yield.
5.2 Inverter Clipping Considerations:
- Clipping losses (due to inverter capacity limits) can reduce the energy gain from reflectors by 0.5%–2.8%. However, the optimal placement (centered under the torque tube) remains the same.
6. Why Reflectors Work Best in Cloudy, High-Latitude Regions
Artificial reflectors are particularly effective in regions with high cloud cover and low natural ground albedo, such as Seattle. These areas benefit from higher diffuse irradiance, which enhances the bifacial gain. In contrast, sunny regions like Tucson, Arizona, see smaller energy gains but can still benefit from reflectors.
7. Key Takeaways for Solar Developers
Maximize Energy Yield: Use 70% reflective materials and place reflectors directly under the module for optimal performance.
Economic Viability: Reflectors are most cost-effective in regions with high LCOE and low energy yield, such as cloudy or high-latitude areas.
Consider Clipping: Account for inverter clipping losses when designing systems with reflectors to ensure accurate energy yield predictions.
8. Conclusion
Artificial ground reflectors offer a promising solution to enhance the performance of single-axis-tracked bifacial PV systems. By optimizing reflector size, placement, and material properties, solar developers can significantly boost energy yield and improve the economic viability of their projects, especially in regions with low natural ground albedo.
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Keyphrase:
Artificial ground reflectors for bifacial solar systems
Keyphrase:
Artificial ground reflectors for bifacial solar systems
Keywords:
- Artificial ground reflectors
- Bifacial solar systems
- Single-axis-tracked PV
- Solar energy yield optimization
- Ground albedo
- Solar reflector placement
- Solar reflector size
- Solar reflector economics
- Inverter clipping losses
- High-albedo materials
