In-Field and Laboratory Hail Study Quantifies Stow Effectiveness to Support Solar Plant Extreme Weather Mitigation Strategies
The Challenge: Closing the Data Gap in Extreme Weather Planning
As extreme weather events grow in frequency and severity, utility-scale solar developers must proactively protect their assets—especially in hail-prone regions like the Midwest and South-Central U.S. Traditional lab models have offered limited insights into real-world hail impact, leaving developers with a gap in data to support operational and design decisions.
To address this, Recurrent Energy partnered with GroundWork Renewables to conduct the industry’s first in-field and lab-validated hail impact study at Recurrent Energy’s 120 MW North Fork Solar Project in Kiowa County, Oklahoma.
The Solution: Measuring and Validating Stow Effectiveness
Together, GroundWork and Recurrent Energy deployed a comprehensive monitoring and testing strategy to quantify how well tracker stow angles reduce hail impact energy—backed by both field measurements and laboratory validation.
On-Site Monitoring with GroundWork’s Hail Event Service
- Captured hailstone size, fall angles, and terminal velocities in real time.
- Provided the industry’s most accurate in-situ data on impact force and frequency.
Tracker Stow Angle Impact
- Compared hail impact at horizontal and 60° plane-of-array (POA) stow positions.
- Quantified energy reduction when modules were stowed ahead of hail events.
Lab Validation at GroundWork’s PV Test Lab
- Matched field data with lab simulations to confirm stow effectiveness.
- Advanced impact models for improved predictive reliability.
Proving Resilience with Empirical Data
This study delivers powerful proof that operational decisions—like stowing modules at optimal angles—can materially reduce hail damage. The combination of real-world data and lab-tested models provides the solar industry with a stronger foundation for risk mitigation planning.
Key Findings:
- Kinetic Energy Reduction: Significant reductions in kinetic energy and impact count were observed when PV modules were stowed, validating the effectiveness of mitigation strategies.
- Field vs. Lab Data: Comparison between field measurements and lab models showed alignment in energy dissipation trends, boosting confidence in predictive modeling.
- Enhanced Impact Models: Laboratory testing revealed more accurate models over simple elastic collision models for hail impact at different angles, improving predictions for probable maximum loss (PML) assessments.
- Storm Microphysics Insights: Analysis of hail fall angles and velocities offered new insights into storm behavior and its effect on impact forces.
- On-Site Monitoring: On-site monitoring proved essential for capturing real-world environmental variables that affect PV module resilience.
The Result: Smarter Decisions, Stronger Projects
With this research, Recurrent Energy demonstrated a commitment to data-driven resilience. GroundWork’s service provided actionable insights that enhanced Recurrent’s stow strategy, validated their operating procedures, and contributed to better-informed long-term planning.
“Hail has been a significant, and increasing, challenge for utility-scale solar installations. Effective mitigation strategies are vital. At Recurrent, we are prioritizing resilient plant designs and operating procedures. GroundWork’s solution helps us quantify and verify our assets’ resilience.”
— Mike Arndt, President, North America, Recurrent Energy
The Takeaway: Proven Strategies Backed by Real-World Evidence
When real-world data backs operational strategies, developers can build more resilient, more reliable solar plants. GroundWork’s partnership with Recurrent Energy sets a new standard for evidence-based weather mitigation in the utility-scale solar industry.
Interested in quantifying hail resilience at your site?
Contact GroundWork to learn how our Hail Event Monitoring and Reporting service can support smarter design and operational decisions.
