benjamin bell slides 6.7.11

8/11/2019 Benjamin Bell Slides 6.7.11

1/34

Wind Turbine Design and Operation: How to Mitigate Impacts

New England Wind Energy Education Project Conference & Workshop

Marlborough, Massachusetts, June 7, 2011

Presented by: Benjamin Bell

Technical by nature


2/34

GL GH offices in 38 locations - 23 countries

Countries with GL Garrad Hassan presence

Countries with newly established GL Garrad Hassan presence

Staff Americas: ~150 Staff Europe: ~460 Staff Asia/AU/NZ: ~70

Beijing, CN

Tokyo, JP

Shanghai, CN

Mumbai, IN

Bangalore, IN

Newcastle, AU

Melbourne, AU

Wellington, NZ

Vancouver, BC

Ottawa, ON

Portland, OR

San Diego, CA

Montreal, QC

Peterborough, NH

Austin, TX

Monterrey, MX

Santiago, CL

Porto Alegre, BR

Heerenveen, NLSint Maarten

Kaiser-Wilhelm-Koog, DE

GlasgowBristol, UKSloughLondonDublin, IR

Paris, FR

Izmir, TK

Copenhagen, DKHinnerupOldenburg, DEHamburgPoland

Lisbon, PTBarcelona, ESZaragozaMadrid

Imola, IT

Cairo, EG


3/34

A US Historical perspective and design evolution

B Design to minimize impacts

C Key factors to consider during development and operation

Contents


4/34

First decade of wind

0

500

1000

1500

2000

2500

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992

Year

CumulativeInstalledCa

pacity(MW

Rest of World

Europe

United States

Foreign Companies

VestasNordtank

Bonus

Micon

Windmatic

Howden

WEG

Aeroman

Nedwind

Mitsubishi

US Companies

US Windpower (KENETECH)

Flowind

ESI

Fayette

Enertech

Carter

JacobsDynergy

UTRC

U.S DiscontinuesRenewable Energy

Incentives in 1985

Period of IrrationalExuberance

(Source: Walt Musial NREL)


5/34

Turbines deployed in the 1980s


6/34

US installed wind power capacity in 1999

(Source: www.windpoweringamerica.gov)


7/34



C Key factors to consider during the build and operation

Contents


8/34

Tube or lattice towers?


9/34

Upwind or downwind rotors?


10/34

Horizontal- or vertical-axis rotors?


11/34

How many blades?


12/34

Small or large rotors?


13/34

Wind turbine design evolution size and rating

1982, 18 m dia., 100 kW 2008, 126 m dia. , 7.5 MW


14/34

Big blades

but not the biggest.


15/34

GL GH Offices

US installed wind power capacity 2010

(Source: www.windpoweringamerica.gov)


16/34

Boeing 747

Already the worlds biggest rotating machines

3.6 MW

Source Siemens Wind Power

108 cycles

2.3 MW


17/34



C Key factors to consider during development and operation

Contents


18/34

Environmental review and permitting

Review of endangered species

Avian and bat studies

Visual aesthetic studies

Flicker studies

Historical and archeological review

Wetlands review Noise studies

(Source: Siemens Wind Power)


19/34

Mitigating impacts

Design:

Proper siting

Upwind versus downwind

Number of blades

Tip speed and design

Tubular versus lattice towers Non reflective coatings

Audio visual warning systems

Operation:

Lighting systems

Dusk/dawn idling a case study


20/34

Mitigating impact on wildlifeAccording to current studies:

3 bat species account for a majority of mortalities at wind farms:Hoary Bat Eastern Red Bat Silver-haired Bat

All three bats are migratory

None of the species are currently classified as threatened or endangered

Bat fatalities peak during the late summer and early fall migration Similar, but smaller peak during spring migration period

Exact reason behind why and when bats collide with turbines is unknown


21/34

Project development and permitting Threatened and Endangered bats can pose a permitting risk to project development

Endangered Species Act State Wildlife Laws

Comprehensive Permit Application - State

Take of any bat species can create a large PR problem

Prior to permitting significant studies must take place

Can last several nights to several months

Cost ranges from $50k to $100k+

Current technology can not always decipherbeyond genus

Poses large problem in understanding whatimpacts will be to protected species

Likely that if bats do occur on project site,

state wildlife agency will recommend 2-yearspost-construction monitoring

Cost ~$50k+ per year


22/34

Reasons for bat mortalities

Unknown why bats are killed by turbines or why certain species appear to be

more affected than others. There is growing information about the mortalityevents and reasons for the mortality.

Bats can be killed by direct collision mortality or from barotraumas by flyinginto the low-pressure zone behind a blade

Mortalities appear to be concentrated during low wind speed nights, duringthe migratory periods, and possibly shortly before and after the passage ofstorms

Suggestions include: proximity, attraction, migratory behavior

Greatest impacts are being seen at forested ridge tops in the East. Lowestmortalities in the West


23/34

Infrared image of bat collision


24/34

Bat curtailment study summary

The purpose of this project was to analyze, estimate, and quantify the impacts of batcurtailment strategies on the energy output of wind farms

Comparison to actual mortality reduction estimates were limited by the lack of fieldstudies available

Measurement data from 60 sites, over 170 years of time series power data

Data was matched with local daily sunset/sunrise times

Reproduced field studies:

April-November, night hours, full curtailment April-November, night hours, 5.0 m/s cut-In

April-November, night hours, 6.5 m/s cut-In


25/34

Casselman wind farm in Pennsylvania


26/34

Increased cut-in wind speeds


27/34

Bat fatality study for higher cut-in wind speeds

Casselman Wind Project, Pennsylvania


28/34

Regional differences in energy impact


29/34

Bat curtailment and energy impact

Northeast

Time Period: Apr-Nov

Night Curtailment

Annual

Energy Loss

Bat Mortality

Reduction 2, 3Curtailment

Effectiveness*

Full Curtailment 31% Assumed > 90% 3

6.5 m/s Curtailment 3% 44-93% 15-30

5.0 m/s Curtailment 1% 44-93% 60-130

* Curtailment effectiveness = % Bat Mortality Reduction / % Energy Loss


30/34

GL GH perspective on bat curtailment

Curtailment is one method to reduce bird and bat mortality risks,but it shouldnt necessarily be the first approach.

GL GH supports proper siting of projects, adequate surveys, andthe use of other mitigation techniques as ways to prevent sitemortality.

Post-construction baseline studies and fatality monitoring may bea first step to understanding if curtailment is a viable approach.


31/34

Regional differences and local siting benefits

Casselman Project

New York Projects

~Northeast / Mid-Atlantic ~ Other


32/34

Summary Over the past 30 years wind turbine technologies have evolved and many

environmental impacts have been mitigated through smart design, proper siting and

responsible operation. Review of endangered species, avian and bat studies, visual aesthetic studies,

historical and archeological review, wetlands review, and noise studies are common inwind project environmental review and permitting.

A case study showed that at wind farms with bat curtailment studies, low wind speedcurtailment is an effective operating strategy for reducing bat mortality from wind

turbines by offering reductions in bat mortality in exchange for modest losses in energy. Additional research is needed to determine the causes of bat mortality at wind farms

and other environmental impacts which could lead to more effective curtailmentmethods and prevention devices. Additional research will also improve siting and othermitigation methods that reduce the need for curtailment.

Disclaimer: Bat mortality reductions are based on a limited number of studies at sites

with observed high bat mortality. Caution should be taken in extrapolating mortalityreductions to other sites as the magnitude and the type of bat mortality is site specific.Projects that are sited to avoid bat interference or that employ other mitigationtechniques may not see comparable mortality reductions.


33/34

References

1. GL GH Environmental Permitting Services

2. Bat Conservation International: http://www.batcon.org/

3. NREL Wind-Wildlife Impacts Literature Database (WILD): http://www.nrel.gov/wind/wild.html

4. Arnett et al., Patterns of Bat Fatalities at Wind Energy Facilities in North America,The Journal ofWildlife Management, 2008

5. Baerwald et al., A Large-Scale Mitigation Experiment to Reduce Bat Fatalities at Wind EnergyFacilities,The Journal of Wildlife Management, 2009

6. Arnett et al., Altering Turbine Speed Reduces Bat Mortality at Wind-Energy Facilities,Frontiers in

Ecology and the Environment, 2010

7. Arnett et al., Effectiveness of Changing Wind Turbine Cut-in Speed to Reduce Bat Fatalities atWind Facilities,Annual Report for the Bats and Wind Energy Cooperative and the PennsylvaniaGame Commission, May 2010

8. Hunz et al., Ecological Impacts of Wind Energy Development on Bats: Questions, ResearchNeeds, and Hypotheses, Frontiers in Ecology and the Environment, 2007

9. National Wind Coordinating Collaborative, Wind Turbine Interactions with Birds, Bats, and theirHabitats: A Summary of Research Results and Priority Questions, Spring 2010

10. Barclay, R. Bat Detectors: Their Uses and Abuses; Capabilities, Limitations, and Utility inAssessing Use and Impacts of Wind Farms,University of Calgary
http://www.batcon.org/http://www.nrel.gov/wind/wild.htmlhttp://www.nrel.gov/wind/wild.htmlhttp://www.batcon.org/


34/34

For more information please contact:

Benjamin Bell

President and CEO

GL Garrad Hassan America, Inc.

45 Main Street, Suite 302Peterborough, NH 03458

(603)924-8800

[email protected]

www.gl-garradhassan.com

Thank You!

benjamin bell slides 6.7.11

Documents