3D backtracking algorithms minimize shading issues in solar trackers by significantly improving the management of inter-row shading, especially on uneven or complex terrain where traditional backtracking methods fall short. Unlike classical backtracking that considers only East-West slopes, 3D backtracking accounts for terrain inclinations and slopes in multiple directions—including North-South and irregular topographies—thus preventing corner and diagonal shadows that can drastically reduce photovoltaic (PV) output.
How 3D Backtracking Minimizes Shading:
- Terrain-Aware Angle Adjustment: 3D backtracking algorithms analyze the 3D topography of the solar site, using advanced polygonal and geometrical analyses to determine the optimal tracker tilt angles. This involves calculating the precise positions of panels to avoid casting shadows on adjacent rows, even in sites with complex slopes and irregular terrain elevations.
- Dynamic Optimization for Low Sun Angles: At times when the sun is near the horizon (sunrise and sunset), trackers move to angles that prevent shadows from falling on the back rows. 3D backtracking dynamically adjusts these angles considering multiple directional slopes, which traditional algorithms that focus only on one slope direction fail to do effectively.
- Local Computation for Real-Time Efficiency: Some 3D backtracking systems perform significant computational optimization ahead of time to create angle transformation tables. These allow individual trackers or tracker control units (TCUs) to quickly compute the best positioning locally without relying on continuous central communication, improving reliability and performance.
- Maximizing Energy Yield Despite Minor Shading: While traditional backtracking aims to completely eliminate shading—sometimes at the cost of not orienting the panels optimally toward the sun—3D backtracking smartly balances between minimizing shading and maximizing sun exposure, even tolerating minor edge shading to improve total energy harvest.
Performance Gains:
- Implementation of 3D backtracking algorithms has resulted in measurable energy yield improvements, with reported gains such as up to 6.2% increase in production in tested projects and nearly complete elimination of shading during low sun elevation times.
- The system effectively reduces shading to nearly zero even in sites with slopes under 3%, confirming its ability to adapt well to common irregular terrain.
In summary, 3D backtracking algorithms minimize shading issues by taking a comprehensive 3D approach to terrain and solar geometry, optimizing tracker angles in multiple dimensions to prevent inter-row shading and thus maximize the overall photovoltaic energy output on challenging sites.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-3d-backtracking-algorithms-minimize-shading-issues-in-solar-trackers/
