Skip to main content

​
Summary

Wind Stow is a protective mechanism that commands single-axis trackers to a specified angle when wind conditions exceed safe operating limits. PlantPredict supports two wind stow implementations: PlantPredict Wind Stow (threshold-based comparison using wind gust speed) and Array Technologies Wind Stow (external API-based calculation using proprietary algorithms). Wind stow has the highest priority in the tracker angle determination hierarchy, overriding both base tracking and irradiance optimization.

​
Inputs

NameSymbolUnitsDescription
Wind Gust Speedvgustv_{gust}m/sWind gust speed from weather data
Wind Stow Thresholdvthresholdv_{threshold}m/sThreshold for stow activation
Current Tracker Angleα\alphadegreesTracker rotation angle before wind stow check
Wind Stow Angleαstow\alpha_{stow}degreesStow position

​
Outputs

NameSymbolUnitsDescription
Commanded Tracker Angleαfinal\alpha_{final}degreesFinal tracker rotation angle after wind stow logic

​
Detailed Description

​
Override Hierarchy

Wind stow has the highest priority in PlantPredict’s tracker angle determination. When wind stow is activated, it overrides both the base tracking angle and any irradiance optimization adjustments. The terrain-aware backtracking algorithm is not compatible with the irradiance optimization and wind stow algorithms; it operates as a standalone tracking mode.

​
PlantPredict Wind Stow

PlantPredict’s built-in wind stow activates when wind gust speed exceeds the configured threshold: vgust>vthresholdv_{gust} > v_{threshold} When triggered, the tracker moves to the stow angle while preserving its east/west orientation: αfinal=sign(α)×αstow\alpha_{final} = \text{sign}(\alpha) \times \alpha_{stow} This mode requires WindGust data in the weather file; wind gust values are not synthesized from mean wind speed.

​
Array Technologies Wind Stow

When configured to use Array Technologies mode, PlantPredict sends tracker configuration and weather data to the Array Technologies API. The service performs proprietary wind stow calculations and returns time-series of stow angles. PlantPredict applies the returned angles directly, overriding internal tracking calculations. The Array Technologies algorithms are proprietary and not documented here.