March 24 2011Rev 4 – CD Harbourt
GE Infrastructure – Energy
Wind Energy 101Introduction to wind turbine technology
Cy Harbourt
GE Energy
March 24, 2011
Virginia Mountain Section IEEE
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March 24 2011Rev 4 – CD Harbourt
•This presentation was originally authored by Aaron Barr from GE Energy in Greenville, SC and was presented at the December meeting of the ASME in Greenville.
•Thanks to Aaron for making it available to us
March 24 2011Rev 4 – CD Harbourt
Agenda
• Introduction – GE and Wind energy
•Wind Energy first principles
•Wind energy market
•Wind Turbines – component view
•GE Wind Energy opportunities
•Q & A session
3
Introduction
05 November 2010Rev 2
416 December 2010Rev 3 – Aaron Barr
March 24 2011Rev 4 – CD Harbourt
Early wind energy engineer…
Of all the forces of nature, I should think the wind contains the largest amount of motive power.
All the power exerted by all the men, beasts, running-water, and steam, shall not equal the one hundredth part of what is exerted by the blowing of the wind.
Quite possibly one of the greatest discoveries, will be the taming and harnessing of it.
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– Abraham Lincoln - 1860– Abraham Lincoln - 1860
March 24 2011Rev 4 – CD Harbourt
“I'd put my money on the sun and solar energy. What a source of power! I hope we don't have to wait ‘til oil and coal run outbefore we tackle that.”
~Thomas Edison - 1931
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March 24 2011Rev 4 – CD Harbourt
Europe Renewables HeadquartersSalzbergen, Germany
Energy Learning CenterNiskayuna, NY
Global Research CenterMunich, Germany
JF Welch Technology CenterBangalore, India
Global Research CenterShanghai, China
Global Research CenterNiskayuna, NY
Global Renewables HeadquartersSchenectady, NY
GE Wind ManufacturingGreenville, SCPensacola, FLTehachapi, CA
Powerful Heritage… Innovative Solutions
Energy EngineeringGreenville, SC
Global team with diverse expertise
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Power Conversion Center of ExcellenceSalem, VA
March 24 2011Rev 4 – CD Harbourt
Wind
• Leading N. American
wind turbine supplier
• 6x unit growth since ‘02
•16,000+ 1.5MW installed globallyBiogas
• Power range: 0.25 MW-4 MW
• Fuel flexibility: Natural gas or a variety of renewable or alternative gases
Solar
• Residential, commercial and utility applications
• Largest commercial solar project in Asia
• PrimeStar Solar thin film technology investment
• 10 manufacturing/assembly sites• 4,000 global employees• Installed base: 24+GW• Projects in 40+ countries•10,000 sub-supplier jobs created
GE Energy….The largest renewables business on Earth
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March 24 2011Rev 4 – CD Harbourt
Wind Turbine Components
Rotor35 metric tons77 meters diameter
Nacelle52 metric tons
Tower120+ metric tons60 to 100 metersCar (for scale)
GE 1.5 MW1200-1700 HouseholdsWorsham Field
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March 24 2011Rev 4 – CD Harbourt
Small vs. Big wind energy
Two Related technologies
Different applications and economics
10kw
You
1500kw
Utility-Scale Wind Power - 850 - 6000 kW
•Owned by utilities, multi-million $ companies
•Installed on wind farms, 10 – 600 MW
•Professional maintenance crews
•>13 mph (6 m/s) avg wind speed
Small Wind Power - 300 W - 250 kW
•Individual homes, farms, businesses, etc.
•On the “customer side” of the meter
•Or…off the grid entirely
•High reliability, low maintenance
•>9 mph (4 m/s) avg wind speed
Source: NREL
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March 24 2011Rev 4 – CD Harbourt
1981 1985 1990 1996 1999 2001Rotor Dia. (m)10 17 27 40 50 71
KW 25 100 225 550 750 1,500
200588
2,500
Increased size, improved performance and technology innovation
Wind energy now cost competitive with conventional fuels
CoE
From ~60 cents/kWh down to 5-6 cents/kWh for the period
Wind Turbine Growth: Size, Power and Cost
2010+125+
7,500+
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Wind Energy First Principles
05 November 2010Rev 2
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March 24 2011Rev 4 – CD Harbourt
Wind Turbine PrinciplesConverting one form of energy to another
KineticEnergy
Mechanical Energy
Electrical Energy
Overall: 42 – 50% Efficient Today… Theoretical Maximum is 59.3% (no losses)
Component
Rotor Gearbox Generator Converter
Efficiency 45-52% 95-97% 97-98% 96-99%
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March 24 2011Rev 4 – CD Harbourt
Rotor power
Ideal (Betz limit)
(wind velocity slows by 2/3)
Rotor power
Ideal (Betz limit)
(wind velocity slows by 2/3)
V1
V2
area swept rotor A
density air
tcoefficien power rotor
:
312
1
p
p
C
where
CρAVP
131
2
p
VV
:where
5930C
.
Wind Turbine Energy Capture
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Source: “Wind turbines: Fundamentals, Technologies, Application and Economics”, Erich Hau, ISBN: 3540570640; (April 30, 2000)
Cp vs. PU Exit Velocity
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 0.2 0.4 0.6 0.8 1 1.2
PU Exit Velocity
Cp
Cp vs. PU Exit VelocityCp vs. PU Exit Velocity
March 24 2011Rev 4 – CD Harbourt
Source: “Wind turbines: Fundamentals, Technologies, Application and Economics”, Erich Hau, ISBN: 3540570640; (April 30, 2000)
Unsteady dynamics•Turbulence•Shear•Density changes
Design challenges•Across diameter•15% average difference•30% Instant difference
Loads analysis critical to maintaining 20-year life
Wind Variation
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March 24 2011Rev 4 – CD Harbourt
Wind energy technologies
3-blade horizontal axis turbines are optimal
Wind is….
•Really solar power!
•Uneven heating of earth
•Coreolis - earth rotation
•Moving mass
•Kinetic Energy!!!
AreaSweptA
velocity windV
density airρ
EfficiencyC
ρAV2
1CP
P
3Pw
59.3% 16/27CMax P
DRAG LIFT
Source: NREL
1616
March 24 2011Rev 4 – CD Harbourt
Horizontal axis Horizontal axis Vertical axis 3-bladed 2-bladed
( HAWT )( VAWT )
Wind Turbine Design Concepts
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March 24 2011Rev 4 – CD Harbourt
0
0.1
0.2
0.3
0.4
0.5
0.6
0 5 10 15
= Tip Speed Ratio
Cp
1 Blade
2 Blades
3 Blades
4 Blades
Ideal
= Vtip / V1
Blade calculations include realistic airfoils, L/D, and tip losses. Each point along a curve represents an optimized airfoil for given tip speed ratio. Ideal curve is zero drag optimum with rotational wake.
-4 blades cost more than 3 – provide marginal performance benefit
-2 blades provides loads balancing issue - requires teetered hub/downwind rotor
-3 blades (tripod) provides solution to loads resolution
Actual Cp is constrained by Betz limit
Also: noise (tip speed), loads, blade geometry
Why 3 Blades?
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March 24 2011Rev 4 – CD Harbourt
Aerodynamic LiftU – Windspeed, m/sR – Blade radial position, m - Rotational Velocity, rad/s
Varies with windspeed - Local twist angle, deg
Varies with radius - Blade pitch angle, deg
Varies with windspeed - Angle of attack, deg
Varies with radius and wind speed
Wind
Roto
r Pla
ne
0-P
itch
Lin
eC
hord
Lin
eFl
ow D
irec
tion
Thrust
Torque
Drag
Lift
U
R
Trade-offCost: Thrust loads = Material, weight
Benefit: Torque Loads = PowerThrust:Torque ~ 10:1
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March 24 2011Rev 4 – CD Harbourt
Power Curve Terminology
Power output vs. wind speed at hub height – 10min average wind speeds Example: official power curve for 1.5s
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56 MPH!
56 MPH!
Wind turbines
Component view
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March 24 2011Rev 4 – CD Harbourt
Nacelle & Hub components
Rotor main shaft
Pitch drive
Hub
Main bearing
‘Top box’:low voltage, control…
Generator
Bed Frame Yaw
drives
High-speed coupling
Gearbox
Wind Sensors
GE 1.5 wind turbine52 metric ton nacelle35 metric ton rotor
Pitch bearing
Mechanical brake
Yaw bearing
6-ft
Hokie Bird is registered trademark of Virginia Tech 22
March 24 2011Rev 4 – CD Harbourt
Wind turbine assembly
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March 24 2011Rev 4 – CD Harbourt
Wind turbine installation
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March 24 2011Rev 4 – CD Harbourt
Blades – Product Differentiators
Blades critical to performance:Energy capture … revenueAerodynamic loads… cost
Design optimization:MaterialsAirfoil geometryLoadsNoiseEfficiencyCostLogistics
Spar CapLeading Edge
Shell
Trailing Edge
Shear Webs
Blade Cross-section
Blade Fatigue testing
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Source: National Renewable Energy LabSource: National Renewable Energy Lab
March 24 2011Rev 4 – CD Harbourt
Hub & Pitch system
Hub Assembly
Pitch system… critical to safety Pitch blades out of the windMaintain rated powerShut turbine down
Source: GE energy – 2007 Sandia reliability conferenceSource: GE energy – 2007 Sandia reliability conference
Source: GE energy – 2007 Sandia reliability conferenceSource: GE energy – 2007 Sandia reliability conference
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March 24 2011Rev 4 – CD Harbourt
Gearbox and mechanical drivetrain
MW-scale Gearbox
Torque arms
Input - ~15RPM
Planetary stage
Output – 1600RPM
Parallel stages
Source: GE transportation
Drivetrain… critical to reliabilityDesign optimizations:Reliability… 20 year lifeTorque capabilityMaintainabilitySize, weight, CostGlobal source-ability
Source: GE energy – 2007 Sandia reliability conferenceSource: GE energy – 2007 Sandia reliability conference
Root cause analysis processRoot cause analysis process
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March 24 2011Rev 4 – CD Harbourt
3
3GEAR BOX
WOUND ROTOR INDUCTION GENERATOR TRANSFORMER
GRID
IGBT POWER CONVERTERS
3
3
GEAR BOX
INDUCTION GENERATOR TRANSFORMER
GRID
GEAR BOX
SYNCHRONOUSGENERATOR TRANSFORMER
GRID
Rectifier
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IGBTInverter
2) Doubly-Fed High speed Generator
1) Fixed Speed System – no converter
3) High speed synchronous generator
Wind Turbine generator types
C) Direct-drive generator – no gearbox
Pros: Low cost, simplicity
Cons: Poor performance
Poor grid integration
Pros: Low cost, simplicity
Cons: Poor performance
Poor grid integration
Pros: Grid integration, controllability
Cons: Higher power electronics cost
Pros: Grid integration, controllability
Cons: Higher power electronics cost
Pros: Excellent compromise of cost & gridPros: Excellent compromise of cost & grid
Pros: Elimination of gearbox – reliability
Cons: Large generator – high cost
Pros: Elimination of gearbox – reliability
Cons: Large generator – high cost
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Generator choice is critical to operational flexibility & grid integration
March 24 2011Rev 4 – CD Harbourt
Source: GE energy – 2007 Sandia reliability conferenceSource: GE energy – 2007 Sandia reliability conference
Tower and Power Electronics
View of 2.5MW tower base
Source; GE EnergySource; GE Energy
Power conversion… critical to flexibilityGrid integration and complianceVariable speed capabilityDesigned & manufactured at GE in Salem, VA
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Wind Energy Market
30
2009
31
2030
Power Required Doubles !32
March 24 2011Rev 4 – CD Harbourt
Pasterze Glacier, Austria
Environmental Challenges
Increasing atmospheric CO2 is warming the planet
Power generation is leading cause of CO2 emissions
1875 2004
Carbon constraints increase demand for renewable energy
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March 24 2011Rev 4 – CD Harbourt
US Power Generation Mix
Half the US power is coal-fired
2009 new installs : 39% wind, 9% coal
Source: Energy Information Administration
Non Renewable
Non Renewable
RenewableRenewable
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March 24 2011Rev 4 – CD Harbourt
> 8
7- 8
6-7
4-6
< 4
Wind Speed (m/s @ 50m)
US percent of electricity consumption
from wind: ~1%
(10 m/s = 22.4 mph)
Wind Resource – U.S.A.
Midwestern United States is ‘Saudi Arabia of Wind’
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March 24 2011Rev 4 – CD Harbourt
> 8
7- 8
6-7
4-6
< 4
Wind Speed (m/s @ 50m)
Wind power penetration
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
Denmark Spain Germany Ireland Portugal Greece Netherlands EU
% o
f e
lec
tric
ity
co
ns
um
pti
on
Source: BTM Consult ApS - September 2005
Wind power penetration
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
Denmark Spain Germany Ireland Portugal Greece Netherlands EU
% o
f e
lec
tric
ity
co
ns
um
pti
on
Source: BTM Consult ApS - September 2005
(10 m/s = 22.4 mph)
Wind Resource - Europe
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March 24 2011Rev 4 – CD Harbourt
Top Wind Power countries
US and China with more than 1/3 of the World’s MW
China expected to take #1 position by 2015
Source: BTM Consult [3]
MW % world
35,195 22%
25,853 16%
25,813 16%
18,784 12%
10,827 7%
4,845 3%
4,775 3%
4,340 3%
3,474 2%
3,408 2%
22,770 14%
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March 24 2011Rev 4 – CD Harbourt
Top Windpower US States
26.8%
10.4%
7.95%
5.6%5.1%5.0%
4.4%
3.6%
3.5%
3.42%
24.1%
TexasIowaCaliforniaWashingtonMinnesotaOregonIllinoisNew YorkColoradoNorth Dakota26 Others
Texas, Iowa and California generate ~½ of total
Dakotas could power the entire US
CapacityTop 10 producers
Source: AWEA
Source: AWEA
Source: AWEA
Production
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http://www.awea.org/http://www.awea.org/
March 24 2011Rev 4 – CD Harbourt
Source: AWEA
2005: 5 turbine manufacturer active in US
2009: 10+….Competition is growing, GE remains in good position
Wind Industry Growth - USA2009 Installs2009 Installs
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Wind Energy Grid Challenges
05 November 2010Rev 2
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March 24 2011Rev 4 – CD Harbourt
Utility Scale Wind Generation …5-10% Penetration Easily Managed
Managing a Variable Resource
•1 to 48 Hour Wind Forecasting
•Coordinated Economic Dispatch of Hydro, GT, .…
Danish Transmission Grid w/ Interconnects & Offshore Sites
Jutland - Western Denmark
3000 MW Wind Capacity Out of 6800 MW Total
•20% of Average Demand Supplied by Wind
•Max 1 Hr Penetration Is 80%, max 20% change per hour
•HVDC Link to Norway, Hydro As Virtual Storage
Wind Site Forecasting
Utility Windfarms
100-500 MW Farms Being Developed
•Grid Codes Rapidly Evolving150 MW Trent Mesa, TX
EON - LVRT spec
March 24 2011Rev 4 – CD Harbourt
Application Characteristics
Single WTGs Large Farms Multiple Farms
Low Penetration High Penetration
Per
form
ance
Req
uir
emen
ts
Bas
ic
A
dvan
ced
LVRT
O/U VoltageOvercurrent
O/U Frequency
Anti-islandingAnti-islanding
PF control
Voltage control(old DVAR)
Zero Zero PowerPower
Voltage Voltage ControlControl
Fancy Voltage Control
(WindVAR)
None
Protection Volt/VAR Control
Active Power Control
None
LVRT – no trip(e.g. Taiban, E-ON)
Zero VRT – no tripZero VRT – no trip(e.g. Western (e.g. Western
Australia)Australia)
LVRT with controlled LVRT with controlled current injectioncurrent injection
Curtailment
Frequency Frequency ResponseResponse
Reserve Reserve FunctionsFunctions
Active Anti-islanding,Active Anti-islanding,Torsional, Torsional,
othersothers
Grid Requirements Evolution
EON - LVRT spec
March 24 2011Rev 4 – CD Harbourt
Grid Integration …Critical for Large Scale Wind
Composite (Worst Case) Emergency Voltage
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1.10
1.20
1.30
1.40
1.50
0.0 0.1 1.0 10.0 100.0 1000.0 10000.0
Time (seconds)
Vo
ltag
e (P
U)
Australia
EON
Denmark
France
Scotland
ScotlandEON Denmark
EONLVRT Full Power Tests
Global Transient Voltage Requirements
Rapidly Evolving Grid Codes
• Success of wind is driving sweeping changes
• New electrical control features evolving
• Ride-Thru, Real/Reactive Power control
• Wind needs to be as Grid-Friendly as Traditional Generation for 50 GW Global market
Voltage
Power
March 24 2011Rev 4 – CD Harbourt
Unit Dispatch
0
100
200
300
400
500
600
700
0 2000 4000 6000 8000
Hour
MW
9500
10000
10500
0 60 120 180
MAPS Load MAPS Pgen Total MAPS Base Load
QSS Load QSS Pgen(i) QSS Pgen Total
600 seconds
Voltage Power
Spinning Reserve (Day Ahead Scheduling)
Load Following(5 Minute Dispatch)
Frequency & Tie-line Regulation (Seconds)
Ancillary Services & Wind Variability
multiday forecasting –participation in SMD
<-
Fas
ter
Tim
e S
cale
S
low
er -
>
Operational/Cost Regime
Technology Advancements
Short-term forecasting and wind farm active power management
WTG level active and reactive power controls
March 24 2011Rev 4 – CD Harbourt
Taiban Mesa 204 MW
~ 1500 mi
Colorado Green 162 MW
Windfarm Electrics –Real & Reactive Power Control
Clean volts on
host utility grid
Taiban Plateau 204 MW
March 24 2011Rev 4 – CD Harbourt
GE Wind farms are more stable that conventional synchronous generators.
Voltage recovery of the wind farm is better
Synchronous Generator swings dramatically???
Time (seconds)
Wind Turbine Transient Response
March 24 2011Rev 4 – CD Harbourt
Wind ForecastingEltra, Denmark - 2000 Study
• 1.9GW onshore farms, 16% consumption
• 3.4TWh produced, 1.3TWh miscalculated (38%)
• Climatology-based forecast, inaccuracies up to 800MW
• $12M imbalance payments (0.3c/kWh)
Current State-of-the-Art• Local statistical model + 3D climatology model - 10-15% mean abs error for day-ahead and 5-10% error for 6 hr ahead forecasts• 2005 regulations in Spain provide:
- Penalties for >20% error on 24hr production forecast- Incentives for <10% error over rolling 4hr forecast
• 2003 Cal ISO regulations – unbiased hourly, daily forecasts – settlement monthly for net deviations at average rate• Utilities need short (<6h), med (24-36h) and long term (>72h) forecasts
AWSTruewind forecast using a combination of local statistical models,
and 3D meso-scale climatology
Wind Energy Offshore
05 November 2010Rev 2
48
• US East Coast, Great Lakes, BC, UK, Germany, …
• Proximity to Population & Load Centers
• 10-20 Km Offshore, Water Depths to 10-40 M
Challenges
• Hurricane Exposure, Waves, Sea Bed Stability
• Deep Water Foundations > 40 m Can Open Vast Resource
• Tough Service Environment, Need Autonomous Operation GE 7x 3.6 MW –
Arklow Banks, Irish Sea
Offshore Construction,7.2 GW RFP’s in UK
Offshore Wind … GW Scale Renewable
20 GW Potential off NE Coast,Capacity Factors to 50%
March 24 2011Rev 4 – CD Harbourt
Offshore Wind Potential
300300
150150 400400
86008600 750750
300300
900900
27002700200200
Germany
Sweden
Denmark
Ireland
Belgium
Netherlands
86008600 600600
UK 23 GW
83008300 600600
USA
700700
Canada
9.6 GW
Concept / Early Stage
Active Develop
Source: Emerging Energy Research / GE Wind
Significant Offshore Growth Potential . . . Drivers Are:• Renewable Obligations ( UK, US) • Kyoto compliance (Germany, Ireland)
Over 30GW Of Specific Sites In Various Stages Have Been Announced
March 24 2011Rev 4 – CD Harbourt
Offshore Multi-Generational Plan
Depth dependence on weight can be reduced substantially
with a floating foundation system
Now
Phase I
Jacket weight increases with depth even at
constant MW rating
Phase II
Fatigue Effect
?
March 24 2011Rev 4 – CD Harbourt
Floating Wind Challenges
f2 > 1.785 Hz
0.312 < f1 < 0.383 HzExcitation from
rotor operation
Excitation from
blade passing
Current Wind Opportunity(Narrow)
Oil & Gas Opportunity(Wide)
Compliant Floating System
March 24 2011Rev 4 – CD Harbourt
DOE LWST 2 Offshore Program – 5MW+
2 Blade vs 3 Blade Tradeoff
Offshore Turbine System Design• 5-7 MW turbine rating• Design for Availability, Reliability• Access & service strategies• 5-6 c/kWh target in 20 m depth
R&D Focus• Foundation technology• Turbine configuration – 2 vs. 3 blade• Drivetrain development• Rotor development to 140 m• RM&D, CBM
Medium & Deep Water Foundations
Service Technology, RM&D
Wind Turbines
Gearbox Epoxy-Glass
Composite Blades
Electrical Pitch Drives
Transformer & Electrical
Doubly-FedGenerator
Main Shaft & Bearing
Power ElectronicConverter
GE 1.5 MW• 77 M Rotor Diameter
• 50-100 M Tower
• 98% Availability
• Speed 10-20 RPM
• Variable Pitch
Wind Energy Opportunities
05 November 2010Rev 2
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March 24 2011Rev 4 – CD Harbourt
Advanced technology developmentBlade
Construction
Power Electronic
s
Wind Sensin
g
Aerodynamic
optimization
Advanced Load
Control
Advanced Material
Development
Advanced
Generators
Wind Farm Manageme
nt
Compact Drivetrain
s
Advanced Tower Design
Possibilities are endless
Engineers Needed! VT Grad
GE Electrical Engineer 56
March 24 2011Rev 4 – CD Harbourt
Additional ReadingGE Wind Energy external
http://www.gepower.com/businesses/ge_wind_energy/en/index.htm
Organizations
European Wind Energy Association www.ewea.org
American Wind Energy Association www.awea.org
Danish Wind Industry Association www.windpower.org
Windpower Monthly www.wpm.co.nz
AGORES www.agores.org A Global Overview of Renewable Sources
Competition
Overall list: http://energy.sourceguides.com/businesses/byP/wRP/lwindturbine/byN/byName.shtml
Vestas, Denmark www.vestas.com
Enercon www.enercon.de
REpower, Germany www.repower.de/index.php?id=347&L=1
Suzlon ww.suzlon.com
Siemens, Danmark http://www.powergeneration.siemens.com/products-solutions-services/power-plant-soln/windpower/windturbines.htm
Nordex www.nordex.dk
Gamesa, Spain http://www.gamesa.es/index.php/en
Against windpower lobby: www.windkraftgegner.de in German with links to English sites
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