Wind:
New Model Examines Cumulative Impacts of Wind Energy Development on Sensitive Species

Greater Sage-Grouse (Centrocercus urophasianus)

Argonne National Laboratory recently developed a spatially explicit individual-based model prototype for examining the cumulative impacts of wind energy development on populations and habitats of the greater sage-grouse, an important wildlife species that has been affected by energy development in the western United States. The two-year project, “Wind Energy Development in Critical Wildlife Habitats: Considering Cumulative Impacts and the Maintenance of Sustainable Populations,” was initiated in September 2009 with funding from DOE’s Wind and Water Power Program, and Argonne completed testing of the prototype model in July 2011. The fully developed model would allow stakeholders to proactively assess cumulative impacts of extensive regional wind development on sensitive species early in the planning and siting process, identify appropriate mitigation strategies if necessary, and avoid/reduce potentially lengthy and costly project delays.

The sage-grouse has an unusual, complex life history that includes movements between seasonal ranges and the use of traditional strutting grounds (called leks) where males perform courtship displays. Disruption of any portion of the annual life cycle could result in long-term impacts on the species throughout a larger portion of its range. A model that considers the species’ complex life cycle is needed to understand how projects could affect the species’ life cycle and evaluate cumulative impacts of development.

Argonne developed the model as a proof-of-concept for Albany County, Wyoming, an area that currently supports important populations of greater sage-grouse and has high wind energy development potential. The model incorporates life history and seasonal habitat preferences that are unique to this species. Five major processes (seasonal movements, habitat selection, condition change, reproduction, and survivorship) for seven age-sex classes are represented in the model.

The Argonne model provides the ability to predict potential impacts of wind development based on assumed wind deployment scenarios. A comparison of two scenarios (with and without new wind development) is shown in Figure 1. The model predicted both a shift in distribution and a decrease in population size after development. The results of model runs using other tested wind scenarios demonstrated the importance of location and configuration of wind farms.

The model provides valuable information to support siting decisions and minimize ecological impact. With this tool, users can determine the proximate cause of population changes (e.g., changes in survivorship, reproduction, and habitat suitability), and this information could be used to help design improved mitigation strategies. The model can also be adapted and applied to other regions with high wind potential and species that are identified as at-risk from wind development.

Argonne's current effort focuses on improving the model to be a fully functioning, user-friendly tool for land management agencies, planners, developers, and other stakeholders to evaluate the effects of wind development on sage-grouse. Argonne is exploring the application of the model to a larger area (multi-county, metapopultion, or state) using alternative modeling platform. In addition, the model is being refined to incorporate the latest information on sage-grouse biology and the effects of wind energy development.

Figure 1. Argonne National Laboratory's sage-grouse model predictions of distribution and population trajectory under baseline (existing oil and gas development, but no future wind development, left) and Scenario 1 (existing oil and gas development and development of a new 17 km2, 85-turbine wind farm, right). Distribution of individuals during the spring (post-lekking) is shown.

March 2012