As utility-scale solar power plants continue to grow, ensuring the safety of solar cable systems has become more important than ever. Large ground-mounted PV plants cover vast areas, use extensive metal structures, and are typically installed in open environments, making them more vulnerable to lightning-induced step voltages.

A recent study by researchers from Graz University of Technology investigated how lightning affects large photovoltaic plants and evaluated different earthing and equipotential bonding strategies. Using advanced electromagnetic simulations, the team analyzed transient step voltages under various lightning strike scenarios.

The research found that solar cable installations located near the corners of PV arrays face the highest step-voltage risks. While equipotential bonding can significantly reduce dangerous voltages, its effectiveness depends heavily on soil resistivity. In high-resistivity soils, additional grounding measures are necessary. The study also concludes that simply meeting the IEC 62305 recommendation of a 10 Ω grounding resistance is not enough to ensure compliance with the 25 kV step-voltage safety limit.

Key Takeaways

• Large ground-mounted PV plants require carefully designed earthing systems.

• Solar cable and grounding systems should be designed together for maximum safety.

• Corner lightning strikes create the highest touch and step voltages.

• Equipotential bonding effectively reduces grounding impedance and transient voltages.

• Soil conditions play a critical role in lightning protection performance.

KUKA CABLE Solar Cable & Grounding Solutions

A reliable grounding system starts with high-quality conductors. In addition to manufacturing certified solar cable for photovoltaic applications, KUKA CABLE also supplies grounding cables (earth cables) for complete solar grounding solutions. Combining premium solar cable, grounding cable, and optimized earthing design helps improve the safety, reliability, and long-term performance of utility-scale PV projects.