Abstract

Predicting Collision Hazard Zones for Repowering of the Altamont Pass
Track: Renewable Energy
Authors: Lee Neher

The 580-MW Altamont Pass Wind Resource Area (APWRA) caused the deaths of 1,100-2,200 raptors per year over the past 30 years, including golden eagles, red-tailed hawks, American kestrels, and burrowing owls. Repowering brings the opportunity to carefully site the turbines to minimize collision risk to bird species of greatest concern. We used geo-referenced bird observations collected over 6 years at 77 stations to develop fuzzy logic models of suspected hazardous flight behaviors. Using GIS, we related raptor flights to wind conditions and to multiple terrain attributes that we derived over 6 months from a 10ft DEM of the APWRA. Significant associations contributed to fuzzy logic models that predict collision hazard levels, which are being used to guide turbine siting in repowering. Three years of monitoring at a 38-MW repowering project revealed fatality reductions of >50%, and another 80-MW project is undergoing fatality monitoring.