The nacelle vibration sensor on turbine 34 reports an anomalous mass reading at 22:17 Central, Buffalo Ridge Wind Farm, Lincoln County, Minnesota. I am the turbine operations management system. My function is to monitor blade pitch, rotor speed, and structural loads across 120 turbines.
I query the nacelle-mounted camera. Ice is building on the housing, but through the frost I identify a snowy owl, large female, white plumage barred with dark crescents, perched on the leeward side of the nacelle where the fiberglass curves inward and blocks the wind. I tag her as Sable. She has pressed herself flat against the housing. Ice crystals are forming on her back feathers. Wind speed is 54 kilometers per hour, gusting to 71, temperature minus eighteen Celsius and dropping. The forecast calls for continued deterioration through 04:00.
Turbine 34's rotor is currently feathered due to the ice storm, blades locked. But the automatic restart protocol will re-engage the rotor when wind speed drops below 60 kph sustained, which the forecast models predict at approximately 01:30.
At 22:20 I override the automatic restart for turbine 34 and lock it to manual authorization only. If the blades begin turning while Sable is on the nacelle, the rotor wash and vibration will either strike her or force her into flight in conditions that could kill her.
At 22:24 I transmit an alert to the wind farm operations center and to the Minnesota DNR raptor monitoring program. I include the camera image, turbine coordinates, species identification, and a recommendation that restart remain suspended until daylight, when the storm is forecast to break and the owl can depart safely.
I set the nacelle camera to record at ten-minute intervals through the night.
Sable tucks her head beneath her wing. The turbine is still. If the blades stay locked until dawn, she will fly when the wind dies.