Curtailing turbines to protect bats cut electricity generation by up to 15%
Over 78 days, curtailed turbines generated 5% to 15% less electricity. With wind-only curtailment, even a reduction in deaths remained uncertain.
The key idea
Curtailing turbines cost electricity. How much it protected bats depended on the method and how deaths were counted.
The study, in plain language
Thirty turbines were randomly assigned to three conditions: normal operation, curtailment based on wind speed, or a rule that also used acoustic detections of bats. For 78 days, the team searched beneath turbines and adjusted counts for the probability of finding carcasses, how long remains persisted at the site, and the area searched. They completed 2,268 searches and found 296 bats.
Both curtailment rules generated less electricity than normal operation, with a greater loss under the acoustic-informed rule. Wind-only curtailment pointed to fewer deaths, but with uncertainty that included no reduction at all. The estimated reduction was larger under the acoustic-informed rule. The authors treat it as a maximum because carcasses may have fallen outside searched areas.
There is another detail: the two rules curtailed turbines at different wind-speed thresholds, and the acoustic rule operated at higher wind speeds. Therefore, the contribution of the acoustic sensor cannot be isolated. The comparison was between two complete operating strategies, each with estimated fatalities and forgone electricity.
What they found
- Both curtailment strategies generated less electricity than normal operation, with a larger loss under the acoustic option.
- With wind-only curtailment, estimates pointed to fewer deaths but were also consistent with no reduction.
- The reduction under the acoustic option is an upper bound: some animals may have fallen outside the searched area.
How they studied it
Thirty turbines, ten per group, were randomly assigned to three conditions. Over 78 days, researchers combined bat searches, adjusted counts, and records of electricity generated at one wind farm.
What the study cannot show
- The trial took place at one wind farm, and the search area did not adequately characterize where bats fell under the acoustic strategy. Different thresholds make it difficult to attribute differences to a specific component.
Something to think about
When comparing wildlife-protection measures, do people also count the electricity given up and the uncertainty in those figures?
The original study
Efficacy and cost of acoustic-informed and wind speed-only turbine curtailment to reduce bat fatalities at a wind energy facility in Wisconsin
Source under CC BY 4.0. English adaptation and explanation by PaperFlow, with AI assistance. The text has been reorganized for a general audience; it is not the complete paper and does not imply endorsement by its authors.
One study alone does not represent a field's consensus. Educational content does not replace professional advice. Report a possible error.
