1. Introduction With the increasing adoption of renewable energy in Iraq, photovoltaic (PV) power plants have become a critical component of the country's energy transition. However, the harsh environmental conditions, including high temperatures, dust storms, and soil resistivity variations, pose significant challenges to the safe and efficient operation of PV systems. Proper grounding is essential to ensure personnel safety, protect equipment from lightning strikes, and maintain system reliability. This case study explores the implementation of an integrated grounding system for a large-scale PV field in Iraq, addressing design considerations, challenges, and solutions to achieve optimal performance. 2. Project Overview The project involved a 50 MW solar PV plant located in southern Iraq, characterized by: High soil resistivity (ranging from 150 Ω·m to 300 Ω·m) Arid climate with extreme temperatures (up to 50°C in summer) Frequent dust and sandstorms, increasing the risk of electrical faults The grounding system was designed to meet IEEE 80 and IEC 62305 standards, ensuring safety and minimizing ground potential rise (GPR). 3. Grounding System Design 3.1 Key Challenges High soil resistivity – Traditional grounding methods were insufficient. Corrosion risks – Saline and sandy soil conditions accelerated metal degradation. Lightning protection – The region experiences occasional but severe lightning strikes. 3.2 Solutions Implemented Hybrid Grounding Grid A combination of galvanized steel and copper-bonded electrodes was used to balance cost and corrosion resistance. Deep-driven ground rods (3-6 m) were installed to reach lower-resistivity soil layers. Soil Enhancement Bentonite and conductive backfill materials were applied around electrodes to reduce resistance. A ring grounding configuration was adopted around PV arrays and inverters. Lightning Protection Integration Surge arresters were installed at key points. A meshed grounding network connected all metallic structures (PV frames, inverters, and transformers). 4. Performance and Results After implementation, the grounding system achieved: Ground resistance below 5 Ω, meeting international standards. Reduced step and touch potentials, enhancing worker safety. Improved surge protection, minimizing equipment damage from lightning. 5. Lessons Learned Soil treatment is critical in high-resistivity regions. Regular maintenance (e.g., checking corrosion and moisture levels) extends system life. Integrated design (combining PV mounting structures with grounding) improves efficiency. 6. Conclusion The successful deployment of an integrated grounding system in Iraq’s PV field demonstrates the importance of adapting to local environmental conditions. By using hybrid materials, soil enhancement, and lightning protection measures, the project ensured safe and reliable solar power generation. This approach can serve as a model for future PV installations in similar arid and high-resistivity regions.
