For utility-scale solar project developers and EPCs, high winds pose a dual threat: structural damage to photovoltaic (PV) assets and significant energy yield losses caused by overly conservative active stowing.
During Solar Tracker Week, organized by MPV Solar, ARRAY Product Management Director Ariadna Yerpes detailed how our patented mechanical passive wind stow technology helps mitigate these risks. By operating independently of grid power and sensors, this row-by-row system may help reduce average annual energy losses to just 0.05%, while being engineered to support structural integrity from the construction phase onward.
The Structural Challenge: Wind Mitigation vs. Energy Production
Traditional active wind stow strategies force entire solar plants into defensive positions during high wind events, aiming to prioritize baseline safety but potentially causing up to 2.8% in average annual energy production losses.
In traditional solar tracking systems, wind protection typically relies on active mechanisms. These systems depend on an unbroken chain of operational components: anemometers, motors, backup batteries, power supplies, and communication networks. When wind speeds hit a predefined threshold (often around 35 km/h), the entire plant or large blocks of trackers are forced into a flat stow position. While this is designed to help protect the modules, it can lead to substantial energy losses—even for rows not directly experiencing high wind pressure.
How Mechanical Passive Wind Stow Technology Works
ARRAY’s fully mechanical passive wind stow technology utilizes a calibrated clutch integrated into the central structure of each tracker row, mechanically disengaging to a secure position when direct wind pressure exceeds tested torque limits.
Rather than relying on secondary variables like anemometer readings, ARRAY’s system is triggered directly by the physical pressure (torque) the wind exerts on the PV modules. When the wind generates a torque exceeding the system’s calibrated value, the mechanical clutch disengages, and a mechanical damper smoothly allows the row to rotate to a steep-angle position designed with safety in mind in just a few seconds.
Row-by-Row Granularity Engineered to Maximize Uptime
Because the system is 100% mechanical and operates row-by-row, it offers high granularity. During a high-wind event, only the most exposed exterior rows—and approximately 17% of interior rows—typically adapt to the defensive stow position. The remaining rows act under the windbreak and continue sun tracking engineered to optimize energy output.
Technical Comparison: Active vs. Passive Stow
| Feature | Active Wind Mitigation | ARRAY Passive Wind Stow |
| Trigger Mechanism | Anemometers / Wind Speed Sensors | Direct Wind Pressure (Torque) |
| Power Requirement | Grid power, batteries, and communications | None (100% Mechanical) |
| Granularity | Entire plant or large blocks | Row-by-Row / Single row |
| Response Time | Dependent on sensor communication | ~3 Seconds |
| Average Energy Loss | 2.8% average (up to 4.3% max) | 0.05% average |
Helping Reduce LCOE: The Impact on Energy Production
Validated by a study from independent engineering firm DNV, ARRAY’s passive wind stow technology can help reduce average wind-related energy losses to 0.05%, which can help improve project bankability and lead to a lower Levelized Cost of Energy (LCOE) compared to active systems.
Helping to minimize energy loss can directly improve a project’s financial viability. In a 2024 study validated by independent engineering firm DNV utilizing high-resolution, 5-minute wind data, simulations demonstrated that average annual production losses with passive mitigation were 0.05%. In contrast, active systems incurred average losses of 2.8%, ranging up to 4.3% depending on the control algorithm used.
For sites located in regions with frequent or intense wind events—such as Southern Chile, Argentina, or Spain’s Aragon region—heat map simulations indicate that passive wind stow can help recover between 2% and 6% of total annual energy production that might otherwise be lost to active stowing.
Want to dive deeper into the financial impact of wind events? Estimating future energy losses due to wind stow is complex, making financial planning and risk assessment difficult. Discover how ARRAY’s advanced stow strategies can help improve project bankability and navigate the financial complexities of renewable energy operations. Download our detailed white paper, “Is Wind Costing You?”
Designed to Help Protect Assets: From the Construction Phase to Extreme Weather
Because it requires no electrical commissioning to function, ARRAY’s passive wind mitigation is engineered to help protect solar assets from severe wind damage during the highly vulnerable construction phase.
- De-risking Construction:The construction phase of a utility-scale solar asset is highly complex. Since passive mitigation is integrated mechanically into the tracker’s central structure, it is fully available the moment the structure is installed. It does not rely on electrical or communication systems that are not yet operational, helping reduce risk management complexities for EPCs before the plant is even commissioned.
- Engineered for Extreme Weather:As the frequency of extreme weather rises, the system’s design naturally supports asset protection strategies. The maximum-angle stow position designed to deflect high winds is the exact same steep angle utilized to help mitigate damage to PV modules from severe hailstorms, reducing the need to choose between wind stow and hail stow.
Ready to optimize your solar farm’s installation and operation? Pave the way for future growth and conquer your project’s unique environmental challenges with failure-free wind design. Contact ARRAY today to evaluate your site’s wind data using our advanced simulation tools.
