The world is quickly moving towards full scale renewable energy adoption. As such, solar farms are becoming increasingly common. There are over 1,300 operational solar farms in the UK, with many more in the planning or construction stages. They’re taking over brownfield sites, ex-agricultural land, hilly terrain, and even former landfills. This variety of conditions can make installation difficult. You need foundations that are strong and can withstand varying axial and lateral loads. You also need the flexibility to change and scale. And that’s where the screw pile system comes in. A modern, efficient solution for securing solar arrays, screw piles are changing the game for solar farm developers.
Why Screw Piles are popular for solar farms with challenges
What are screw piles?
Screw piles, also known as helical piles, are deep foundation systems made from steel shafts with helical flights. They are rotated into the ground, much like a giant screw, using hydraulic machinery that ensures minimal vibration or soil disturbance. Unlike traditional concrete foundations screw piles don’t require excavation, curing time, or heavy earthworks, making them a specialized solution for specific solar farm applications.
Why steel C-section piles are typically used for solar farms
For most solar farm projects, steel C-section piles are the default choice due to their low cost and straightforward installation. These piles, driven directly into the ground, provide sufficient stability for solar panel arrays in standard soil conditions. Their affordability and ease of use make them ideal for large-scale solar fields on stable, even ground with minimal geotechnical challenges. However, in certain conditions—such as made ground, unstable soil, or uneven terrain—steel C-section piles may not provide the necessary stability or practicality, and screw piles become the preferred solution.
When are screw piles required for solar farms?
Screw piles are typically specified for solar farms when site conditions present specific challenges that make steel C-section piles or concrete foundations less viable. These conditions include:
• Made ground: Sites with fill material, such as reclaimed land or areas with non-natural soil, often lack the uniformity needed for standard piles. Screw piles can penetrate and anchor effectively in these inconsistent layers.
• Unstable ground: In areas with loose, soft, or shifting soils, screw piles provide deep anchoring to ensure long-term stability where steel C-section piles might fail.
• Uneven or sloping terrain: On hilly or uneven sites, screw piles adapt to varying ground levels without the need for extensive leveling or excavation, maintaining structural integrity.
• Environmentally sensitive areas: Where minimizing soil disturbance is critical, such as agricultural land or protected ecosystems, screw piles’ low-impact installation is advantageous.
• Brownfield or capped landfill sites: Screw piles can be installed without penetrating hazardous or unstable layers, offering a secure foundation in contaminated or restricted sites.
Why screw piles are ideal for challenging solar farm sites
1. Rapid installation
Time is critical in solar development. Screw piles allow for quick deployment without waiting for concrete to cure. In challenging conditions, crews can install piles and mount solar panels almost immediately, accelerating project timelines compared to traditional methods.
2. Minimal environmental impact
Because screw piles require no excavation or concrete, they disturb less soil, making them ideal for environmentally sensitive sites or areas with unstable ground. This aligns with the eco-conscious ethos of solar energy.
3. Versatility in difficult conditions
Screw piles excel in challenging environments, such as soft soils, rocky terrain, slopes, or made ground. Their helical design ensures deep, stable anchoring where steel C-section piles or concrete footings might struggle.
4. Reusability and decommissioning
At the end of a solar farm’s life cycle, screw piles can be unscrewed and reused, reducing waste and costs. This is particularly valuable for temporary installations or sites requiring relocation, aligning with solar energy’s sustainability goals.
5. Cost-effectiveness in complex sites
While steel C-section piles are generally cheaper, screw piles reduce costs in challenging conditions by eliminating the need for concrete, extensive excavation, or specialized ground preparation. Their fast installation also lowers machinery and labor expenses.
6. Accessibility for remote or restricted sites
In remote areas where concrete delivery is logistically challenging or on brownfield sites where penetrating the ground is restricted, screw piles offer a practical alternative. Their installation requires minimal equipment, making them suitable for off-grid or constrained locations.
Conclusion
While steel C-section piles remain the go-to choice for solar farms due to their affordability and simplicity in stable, even ground conditions, screw piles are essential for sites with specific challenges like made ground, unstable soil, uneven terrain, or environmental restrictions. Combining speed, sustainability, and adaptability, screw piles provide a robust foundation solution for complex solar farm projects. As solar technology evolves, screw piles will continue to play a critical role in ensuring long-term stability and cost efficiency in challenging environments.
Do you need support with screw pile design, supply, or installation for your solar farm? Get in touch with UK Helix. Our screw pile services can answer all of your needs.