Sandia and the DOE are continuing to fully understand the effects of wind turbines on the environment in which they are placed—to identify the barriers to renewable-energy development and to suggest barrier-mitigation solutions, where available. The effort to develop accurate wind-turbine/radar-interference (WTRI) models will ultimately improve the understanding of their impact and allow viable paths to increase wind-energy deployment across the country.

As part of this effort, Sandia and its partners, BEM International and Peak Spatial Enterprises, have developed TSPEAR. The toolkit supports renewable-energy development interests including developers, consultants, and government-agency users who desire to design, analyze, track progress, and maintain configuration control of energy projects. Initially, the toolkit was designed to support wind-energy developments and assess their impact on potential constraining factors such as radars. The TSPEAR framework and architecture was designed and developed in 2013. The TSPEAR framework uses databases that already exist—developed and maintained by other organizations.

The current TSPEAR version includes a portal capability to combine a commercial planning/management tool with

  • an existing radar model;
  • a line-of-sight tool modified to analyze several radar types including
    • the common air route surveillance radar (CARSR),
    • the air route surveillance radar (ARSR, in this case the ARSR-4), and
    • the airport surveillance radar (ASR, in this case the ASR-9 and ASR-11); and
  • a “Radar Viewshed” user-interface tab.

The new “Radar Viewshed” tab includes a “Select Point for Viewshed” which begins the process. The tool identifies all radars within a 75 mile radius around the selected point. The user also selects the “Elevation” or target height of objects (200, 300, 400, and 500 ft) that would be visible to the particular radars. Once a target height is selected, the user selects the “Compute Viewshed” button and the system creates the viewsheds for all radars selected against the target height selected.

TSPEAR screenshot of Viewshed and user-interface results.

TSPEAR screenshot of Viewshed and user-interface results.

The specific viewshed model extracts a digital elevation model (DEM) around each of the radars from the Shuttle Radar Topography Mission (SRTM) DEM data set. Once extracted, the radar-specific parameters (antenna height, beam pointing, and locations) along with the elevation offset determined by the user-selected target height, are processed into a viewshed and displayed in the map display. For single radars identified, the viewshed is returned in blue. For multiple radars, overlapping areas are depicted in system-defined colors. The returned viewsheds also include a radar symbol for the radars used in the viewshed determination and general name and type information about those radars can be retrieved using a “map tips” feature.

Efforts continue to improve the TSPEAR toolkit’s capabilities. Sandia expects to release TSPEAR Version 1.0 in 2014 to a select number of trial users for feedback.