The Ivanpah solar project is deadlier to birds than previously thought, but the plant still presents a low risk to any species or group of species, according to a new report.
In April 2015, the annual monitoring report prepared for the California Energy Commission estimated 3,504 birds died at the solar power tower plant in the Mojave Desert in its initial year of operation, ending in October 2014. The Year 2 report (PDF), filed late last month, revises that first-year number up to 5,128, while estimating that 5,181 birds died at the plant in the most recent operating year.
The report’s preparer, Western EcoSystems Technology, said the revision to the first-year number reflects improved understanding of bird migration timing and better information about how many of the birds that die at the plant are being found by searchers.
After coming up with a Year 2 estimate using the same methodology as in Year 1 – 6,186 – the company went through and applied the improved methodology to both years and arrived at the revised numbers.
“Overall, the estimates calculated using biologically informed seasons are greater for the first year, lower for the second year, and greater overall for both years combined. The changes are driven by two main factors: re-categorizing a number of detections from winter seasons to fall seasons because a monitoring year ends in fall, and the effect of additional bias trial data from the period between 21 October 2015 and 15 December 2015,” the report said.
In the end, “the new analysis does not change any conclusion of the impacts of the Project” on birds, the report said, categorizing that risk as “low.”