The Challenge
String cable routing on terrain-intensive sites is rarely straightforward. Rows follow slope contours, inverter positions are dictated by civil constraints, and the optimal cable path between them isn’t always the shortest straight line. A large-scale tracker project needed to evaluate three topology options before committing to a cable schedule.
The Three Topologies
Line string — cables run from end of row to combiner in a straight line. Simple to design, but often the longest total run due to backtracking.
U-shape string — cables loop from both ends of a row to a central combiner. Reduces backtracking but requires careful balance between string halves.
Leapfrog string — alternating string polarity routes across rows in a leapfrog pattern. Higher design complexity but shortest total cable path for many terrain configurations.
Results
PVX.AI generated all three topology variants from the same terrain-aware layout model, computing exact cable lengths along terrain-aware routing paths:
- $430K total cable cost reduction using Leapfrog vs. Line baseline
- 14% reduction in total cable run length — directly translating to procurement savings
- Leapfrog was optimal for 73% of inverter blocks; U-shape was preferred for blocks near ridge terrain features
- Full BoM generated for all three scenarios, enabling direct procurement comparison
Outcome
The engineering team adopted a hybrid approach — Leapfrog for most blocks, U-shape for three ridge-adjacent blocks — achieving 96% of the maximum possible savings while avoiding the installation complexity of pure Leapfrog across difficult terrain.