Presentations

Abstract

Wind energy is a vital part of the renewable energy transition, but it can pose a challenge for bats. Acoustically Triggered Curtailment (ATC) is an emerging mitigation strategy involving feathering a wind turbine’s blades when bats are detected to be present.  One of the first commercially available systems to do this is the SMART (Song Meter with Analysis and Remote Transfer) System from Wildlife Acoustics. The SMART System uses advanced acoustic technology to first detect bats at a wind turbine, and then signal the control system to feather the blades until 10 minutes after the bat was last detected. We present analysis of (1) bat activity data and (2) ATC log files collected from a SMART System installed on a UK wind turbine in 2023 and 2024, together with associated wind speeds. We also present thermal imaging showing the SMART System responding to a bat. Analysis of bat calls showed that overall 5% of activity occurred at wind speeds over 5 m/s, but for the Noctule bat this figure was 9%. Bats flew in wind speeds as fast as 9 m/s. These findings underscore the importance of precise, real-time monitoring to identify the times when bats are at risk and to trigger curtailment appropriately.  Data from July to September, when bat activity was greatest, revealed that ATC significantly reduced turbine downtime compared to wind speed-based Operational Curtailment. Numbers of false positive and false negatives are a useful KPI with which to assess SMART and were sufficiently low for continued operation at the site. Our data from a SMART System installed on a wind turbine in the UK suggests ATC has the potential to reduce bat mortality while increasing energy production at wind farms compared with current curtailment protocols.