Background Growth in wind energy production Mortality via. - - PDF document

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Managing bird and bat turbine strikes using weather radar

Robb Diehl & Todd Preston

US Geological Survey Northern Rocky Mountain Science Center Bozeman, MT

Bethany Straw, Simon Thao, & Elise DeGeorge

National Renewable Energy Lab National Wind Technology Center Golden, CO

• Growth in wind energy production
• Mortality via….
• Attraction, turbines likely become so‐called

‘ecological or evolutionary traps’

• Incidental contact
• Options
• Alter the environmental cue, i.e., change how

turbines are perceived ….or….

• Alter the environment, i.e., curtailment

Background

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Habitat quality Perception

High Low High Low <<< Curtailment, siting <<< <<< Alter perception <<<

Background

• Best solutions
• Effective at minimizing impacts to wildlife
• Simple to deploy
• Inexpensive to operate
• Highly reliable, require little maintenance
• Minimize operational energy loss

Background

10/1/2018 3 NEXRAD

NEXt generation weather RADar

TDWR

Terminal Doppler Weather Radar

KLOT, Romeoville, IL Las Vegas, NV (credit Simpson)

Can NEXRAD be used as a real‐time platform for informing curtailment?

e.g., Van Doren and Horton 2018

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NEXRAD metrics

• >140 stations in continental US
• Six measures
• Reflectivity, radial velocity, spectrum width,

differential reflectivity, correlation coefficient, differential phase

• Updates nationally every 6‐10 minutes
• Range limited by altitude of birds and bats, not

sensitivity

Forecasting v. Real‐time

• What is the time horizon for a potential NEXRAD‐based

curtailment scheme?

• Forecasting
• Van Doren and Horton (2018) Science
• Weather‐based model that can forecast a day in advance with

80% accuracy

• Real‐time
• More accurate, requires constant vigilance
• Hybrid scheme
• Shifting accuracy as the movement event approaches
• Integrates planning (forecasting) with realization (real‐time)

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Advantages and disadvantages of using NEXRAD

Advantages

• Existing embedded radar network requires no support
• Highly reliable
• Data is free and centrally archived
• Considerable advances in data processing in recent years

Disadvantages

• Discriminating among target types
• Measuring low‐height targets at range
• Radars do not co‐occur with turbines
• Manage by strategic curtailment

Goals

• Are NEXRAD target identities corroborated by those on

portable radar?

• Do vertebrate target densities identified by NEXRAD index

bat activity?

• Are NEXRAD vertical profiles corroborated by those

measured by portable radar?

• At what range are NEXRAD profiles still operational?
• What proportion of turbines fall within this range?

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Six weather radar parameters

Reflectivity Radial Velocity Spectrum Width Differential Reflectivity Correlation Coefficient Differential Phase

Purple Martin roost ring Precipitation Insects?

Probability of classification ≥95% Probability of classification ≥50%

Biological Precipitation

Biological v. non‐biological discrimination

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Insects Vertebrates Weather

Reflectivity (Z) Classified (p>0.5)

Purple Martin roost ring Precipitation Insects?

Corroborate via portable radar, thermal imaging

Parabolic antenna

• Good data on speed and direction
• Good data on height
• Longer range
• Less comprehensive

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Goals

• Are NEXRAD target identities corroborated by those on

portable radar?

• Do vertebrate target densities identified by NEXRAD index

bat activity?

• Are NEXRAD vertical profiles corroborated by those

measured by portable radar?

• At what range are NEXRAD profiles still operational?
• What proportion of turbines fall within this range?

NEXRAD density profile

see Buler and Diehl 2009

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Portable radar density profile

Goals

• Are NEXRAD target identities corroborated by those on

portable radar?

• Do vertebrate target densities identified by NEXRAD index

bat activity?

• Are NEXRAD vertical profiles corroborated by those

measured by portable radar?

• At what range are NEXRAD profiles still operational?
• What proportion of turbines fall within this range?

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Limited range of overlap

Region of

• verlap
• NEXRAD installed base offers

limited potential to directly monitor airspace at the height

• f rotor swept areas

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e.g., Denver radar

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