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Mark A. RumseyWind Energy Technology Department

Sandia National Laboratories (SNL)

Albuquerque, NM

Wind Turbine Technology

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company,for the United States Department of Energy’s National Nuclear Security Administration

under contract DE-AC04-94AL85000.

Montana State UniversityBozeman, Montana

November 28, 2007

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Calculation of Usable Wind Power

Where: P ≡ usable power in the wind, in Watts

≡ air density, in kg/m3

(1.225 at sea level; 0.993 in Albuquerque, NM)

Cp ≡ coefficient of performance (Cpmax is the Betz Limit ~0.59)

N ≡ mechanical and electrical system efficiency (~0.75)

π ≡ pi (3.142)

R ≡ blade length, in meters

V ≡ inflow wind speed, in meters/second

P = 1/2 Cp N π R2 V3

The drivers!

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Wind Power Densityat 10 meters above ground

US Wind Resource Map

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Wind Industry Trends

1985 1995 2000 2003 2006 2007

All US electrical generation in 2005 was 1,067,019 MW (Source: DOE/EIA)

. . .

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Wind Turbine TechnologyTrends and Challenges

• Wind Turbine specifications:– Electrical Power: 1.5-5.0 MW

– Turbine Weight: 150-500 tons

– Tower Height: 65-100 meters

– Blade Length: 34-60 meters

– Blade Weight: 6-23 tons

• Costs:– System < $3/lb– Blades < $5/lb– ~$1.40/Watt *$0.03-0.06/kWh * (Cost Of Energy)

* - Volatility in the cost of steel and copper- Variable currency exchange rate- Few domestic manufacturers

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Trends - Blade Weight versus Blade Length

SNL

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Wind Turbine Lifecycle

Cyc

lic

Str

ess

Needs for a 30 Yr Lifetime

1978 WECS Design

1982 WECS Design

5 6 7 8 109 11

Aircraft Design

Log10(Cycles to Failure)

WECS ≡ Wind Energy Conversion Systems

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• Blade Technology– Materials and Manufacturing– Structural, Aerodynamic, and Full

Turbine Modeling– Lab and Field Testing, and

specialized Data Acquisition Systems– Advanced Blade Concepts– Sensors, Smart Structures and

Structural Health Monitoring

• System Reliability– Industry Data Collection– Improve reliability of the existing

technology and future designs

s l i d e r

b a s e

e x t e n d e r

NREL/NWTC, Boulder, CO USDA-ARS, Amarillo, TX

Sandia Wind Energy R&D Program

TPI Composites, RI

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Laboratory and Field Testing

BSDS Flatback Gauges

0

2000

4000

6000

8000

10000

12000

-1500 -1000 -500 0 500 1000 1500

Strain (me)

Lo

ad (

lbs)

G17

G18

G19

G20

G29

FAA-SNL AANC,Albuquerque, NM

NREL/NWTC,Boulder, CO

USDA-ARS,Bushland, TX

NREL/NWTC,Boulder, CO

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Materials Testing

• Sandia National Labs and Montana State University– Composite Material Testing (1989-present)

– PI: Prof. John Mandell

– Material Properties (10000+ tests for 175 Materials)

– Database updated once per year

(Last update 04/2007)

http://www.sandia.gov/wind/

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Blade Innovations

• Prototype Sub-scale Blades Manufactured (9 meters)– CX-100

• Carbon spar cap• Glass skin and shear web

– TX-100• Carbon triax in skin for bend-twist coupling• Constant spar cap thickness

– BSDS (Blade System Design Study)• Flatback airfoils• Carbon spar cap• Slenderized planform• Large scale architecture• Highly efficient structural design

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Manufacturing Uncertainty - Big Issue!

As designed

As built

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Current Location of Sensors on a Wind Turbine

• Nacelle – lots• Tower Base – lots• Blades – few to no sensors!

Wind turbineManufacturer: GE EnergyPower Rating: 1.5 MWTower Height: 80 metersBlade Length: 34 metersBlade Weight: 6 tonsJose’s Height: 1.9 meters

Goal: Real-time blade sensing for advanced controls strategies, smart structure and structural health monitoring.

Sensor Opportunities for Turbines

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Failures!

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Questions?

Mark A. Rumsey505-844-3910marumse@sandia.gov

Wind Energy Technology DepartmentSandia National Laboratorieswww.sandia.gov/wind

… for more information:http://www.awea.org/

http://www.eere.energy.gov/windandhydro/