20170925Utah DPU 3.7-2 Informed Curtailment Protocol.pdf

Informed Curtailment Protocol
Glenrock/Rolling Hills/Glenrock III (GRH) Wind Site
and
Seven Mile Hill/Seven Mile Hill II (SMH) Wind Site
This Informed Curtailment protocol applies to PacifiCorp’s Glenrock/Rolling Hills/Glenrock III (GRH) Wind Site and Seven Mile Hill/Seven Mile Hill II (SMH) Wind Site during established time
periods and conditions. “Informed Curtailment” means the use of biological monitors stationed at a
Wind Site, when safe to do so, that have the capability to call for curtailment of one or more turbines based on the protocol set forth in Attachment 2.
The informed curtailment of wind turbine generators due to eagle proximity is an experimental ACP
method intended to help reduce potential turbine collisions with eagles. The goal of informed
curtailment is to identify risky eagle flight behavior/pathways and notify site personnel prior to
potential turbine interaction. Curtailment of turbines will be based on knowledge of eagle activity and observed behaviors for the GRH Wind Site and the SMH Wind Site. An observer will notify site
personnel whenever eagle flights are observed near/toward individual turbines or a grouping of
turbines. An observer will also notify site personnel when risk is reduced to an acceptable level to
release the turbine or grouping of turbines from curtailment.
Due to the geographic extent of the GRH Wind Site and the SMH Wind Site, an observer may not be able to visually identify every eagle in the vicinity of turbines. Positioning of an observer will be as
appropriate to maximize eagle detection in known eagle high use areas. An observer will be mobile,
as necessary, to best detect potential risky flights by eagles. The location of an observer may also be altered over time as eagle activity changes at the GRH Wind Site or the SMH Wind Site.
An observer will notify site personnel of a recommendation to implement turbine curtailment if:
• Eagle(s) are observed within 800 meters of a turbine or grouping of turbines;
• Eagle(s) flight paths are reasonably likely to cross through or near turbine(s) based on observed
heading or assumed trajectory;
• Eagle(s) are observed actively foraging within or near turbines or a group of turbines; or
• Any other behavior is observed in which an observer believes it is reasonably likely that an
eagle(s) is moving toward a potential collision with a turbine.

An observer will use their professional judgment based on knowledge of the GRH Wind Site or the SMH Wind Site and eagle behavior; however, it is understood that eagle activity and other
environmental variables (e.g., wind conditions) are unpredictable.

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An observer will monitor eagle activity while within sight, or until a higher priority risk is observed
(e.g., eagle approaching turbines). An observer will notify site personnel with an “all clear” once
eagle risk is reduced to an acceptable level as determined by the observer. Site personnel will notify
the observer when turbine curtailment has ended. The following is a list of factors that an observer will consider when deciding when to notify facility personnel to resume turbine activity:
• No eagle activity has been observed for 10 consecutive minutes in a turbine group;
• Eagle is perched beyond 800 meters from closest turbine or turbine group;
• Eagle flight direction observed away from turbines or turbine group and eagle is beyond a 1,600 meter buffer;
• Eagle is observed increasing elevation above turbines or turbine group in patterned behavior at
least 400 meters above ground level; or
• Time of day, visibility, or other factors.
Informed Curtailment will not occur if weather conditions create potentially unsafe conditions for an observer, or if observer visibility is heavily impaired.
Under this Protocol, PacifiCorp will employ biological monitors for the purpose of Informed
Curtailment according to the following schedule:
GRH Site – Two biological monitors seven days per week, seven hours per day (0900 hours to 1600 hours, Mountain time), during the months of October, November, December, January,
February and March.
SMH Site – One biological monitor seven days per week, five hours per day (0900 hours to
1400 hours, Mountain time), during the months of December, January, February, and March.
Modifications to this protocol may be warranted over time as new information becomes available.

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