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Providing evidence to improve practice

Individual study: Bat Detection and Shutdown System for Utility-Scale Wind Turbines

Published source details

Electric Power Research Institute (2017) Bat Detection and Shutdown System for Utility-Scale Wind Turbines. EPRI report.


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Automatically reduce turbine blade rotation when bat activity is high Bat Conservation

A randomized, replicated, controlled study in 2015 at a wind energy facility in Wisconsin, USA (Electric Power Research Institute 2017) found that using automated ‘Smart Curtailment’ operating systems that reduced turbine blade rotation speed resulted in fewer fatalities for all bat species combined and for little brown bats Myotis lucifugus than at normally operated wind turbines. There was an 83% reduction in fatalities for all bats and a 90% reduction in fatalities for little brown bats at automated turbines (all bats: average 3 fatalities/day; little brown bats: 0.3 fatalities/day) compared with normally operated turbines (all bats: 18 fatalities/day; little brown bats: 3 fatalities/day). Twenty turbines were randomly selected for the study (10 operated by automated systems and 10 normally operated). At automated turbines, fatality risk was calculated by a predictive model using real-time bat activity and wind speed data every 10 minutes. If fatality risk was high (wind speed ≥3.5 m/s and >1 bat call detected in the previous 10 minutes), rotors were slowed (to ≤2 rpm) for 30 minutes. Normally operated turbines rotated freely. Carcass searches were carried out daily at all turbines in June–October 2015. Electricity generation was reduced by 90 MWh/turbine at automated turbines during the study period.

(Summarised by Anna Berthinussen)