This summer, the U.S. Geological Service (USGS) announced the results of a peer-reviewed study that examined a variety of remote sensing and sampling techniques. Their objective: To determine which technology might be most effective for monitoring how solar power facilities impact flying animals.

Among the study’s findings, detailed in a press release engagingly entitled Videos Reveal Birds, Bats and Bugs near Solar Project Power Towers:

  • “The new study showed that although birds and bats were occasionally seen near the towers at Ivanpah, most observations involved insects.”
  • “Although this study did not quantify impacts, fewer than 15 birds were observed being impacted by the solar flux in more than 700 hours of video.

Recently, the U.S. Geological Service (USGS) issued a press release to announce the results of a peer-reviewed study designed to examine a variety of remote sensing and sampling techniques to determine which technology might be most effective for monitoring how solar power facilities impact flying animals.

The USGS press release headline states the obvious, Videos Reveal Birds, Bats and Bugs near Solar Project Power Towers, but included in the body of the release is some very important news which prompted the investigation in the first place:

  • “The new study showed that although birds and bats were occasionally seen near the towers at Ivanpah, most observations involved insects.”
  • “Although this study did not quantify impacts, fewer than 15 birds were observed being impacted by the solar flux in more than 700 hours of video.

The video footage proves what we have said from the start – the vast majority of so-called “streamers” are insects – not birds.

Ivanpah has one of the most comprehensive approaches to monitoring avian impact at a thermal energy power plant – renewable or fossil fuel. The USGS’s observations and conclusions are entirely consistent with previous findings by independent experts who qualified Ivanpah’s avian impact as “LOW” based on monitoring data gathered during the project’s first two years of operation.

The scientific data is clear: Ivanpah’s impact on avian species is minimal, especially in comparison to other anthropogenic causes of bird mortality. This is important news for those who care about renewable energy and its immediate impact on the local environment.  It’s also a reflection of the extensive efforts that Ivanpah’s owners have undertaken to help reduce avian mortality.

Ivanpah’s owners have mitigated and offset the impacts of the facility by purchasing more than 7,000 acres of private land – double the land used at Ivanpah – and set it aside for permanent habitat protection. The project owners also provided more than five million dollars to manage the land for the benefit of all species, including birds. Ivanpah also maintains a staff of approved biologists on-site to care for, monitor and respond to the needs of animals and plants. To date, Ivanpah’s efforts to protect species, such as the desert tortoise, have yielded invaluable scientific data that will inform future desert development projects.

DISCUSSION

The peer-reviewed paper, Evaluating the Effectiveness of Wildlife Detection and Observation Technologies at a Solar Power Tower Facility, is objective and presents some fascinating information, including information about radar detections and comparisons between thermal and optical cameras, as shown in the following images:


Fig 3. Examples of radar-monitored airspace around a solar tower.

Sweeps of the radar at 0600 PDT (A) and 1100 PDT (B) on 16 May 2014 while operating near Tower 3. Range rings in green denote 250-m intervals out to 1,500 m. The radar is located in the center of the image and is surrounded by ground clutter caused primarily by the heliostat field. Tower 3 causes discernible clutter to the SSW and throughout a ~200° ring at about 1,000 m range. Flying animals, shown as yellow dots (most recent location) with blue tracks (previous locations), were nearly absent in the airspace at 06:00 (A) but occurred in large numbers by 11:00 (B), consistent with patterns observed daily (see text). An animation of (B) is available in S1 Video.

 

Fig 9. Burning insect imaged with different kinds of video cameras.

Single frame from the scientific-grade thermal (SGT) camera (left) and wide dynamic range (WDR) camera (right) showing the same burning insect (arrow) in the Tower 1 flux field at 08:45:35 on 6 September 2014. The tower is just out of the field of view to the right. The images are adjusted to the same spatial scale, and the ~1 m spatial reference is an estimate based on approximate line-of-sight range to the insect. Bright points in the SGT image represent other probable insects in or near the flux field. A dark region in the upper-right of the thermal image is the ‘ghost’ of a target that was in the frame when a non-uniformity correction was performed. An animation from the SGT that concludes in this frame is available in S9 Video.

The complete technical study can be downloaded here.