What is shutdown-on-demand (SDOD) and how does it reduce wind farm bird collision risk?

Q: What is shutdown-on-demand (SDOD) and how does it reduce wind farm bird collision risk?

Shutdown-on-demand (SDOD) is a real-time mitigation strategy where trained observers stationed at vantage points around a wind farm trigger turbine shutdowns when at-risk birds approach the rotor swept zone. The IFC PCFM Handbook identifies observer-led SDOD as the most widely used method for reducing collision risk to soaring birds and raptors. Effectiveness depends entirely on the observer-to-SCADA communication loop.

Shutdown-on-demand (SDOD) lets a wind farm operator stop a turbine in real time when an at-risk bird is heading for the rotor swept zone, preventing the collision before it happens. The IFC PCFM Handbook identifies observer-led SDOD as the most widely used mitigation method for collision risk to soaring birds and raptors, and it is increasingly required at wind farms in flight corridors or near sensitive populations. The mechanism is simple on paper: trained observers at vantage points around the site call shutdowns when target species approach, and SCADA operators stop the turbines until the bird has cleared.

The most widely used method involves observers strategically located at vantage points around the WEF implementing shutdown of one or more turbines in response to birds approaching rotor blades. Turbines are restarted once observers determine that birds are no longer at risk (observer-led shutdown on-demand). Shutdowns of this type are typically short (<30 minutes).

— IFC PCFM Handbook, Box 6.1

How an SDOD program works

Observers stationed at fixed vantage points around the wind farm during high-risk periods
Sightings of target species recorded with species, GPS, time, behavior, and direction of flight
Threat assessment made in real time by the observer, based on the bird’s altitude, distance, and trajectory
Shutdown requested via radio or app to the SCADA operator
Turbines restarted by SCADA once the observer confirms the bird is no longer at risk

Where SDOD breaks down

The IFC PCFM Handbook is direct that communication breakdowns inside the SDOD loop are where the program loses its mitigation value:

Near-miss incidents are relevant when WEFs implement shutdown on-demand of turbines as a mitigation strategy. During shutdown on-demand, an example of a near-miss incident would be when a PCFM target species is observed flying through the rotor swept zone unharmed, and shutdown was initiated too late or not at all because of communication problems between bird observers and SCADA operators.

— IFC PCFM Handbook, §6.2.3

Underneath the comms problem is a data problem. Sightings sit on paper sheets in observer notebooks with no central record, no live view for the project manager, and no aggregate visibility until weeks after the moment to act has passed.