WHY OFFSHORE WIND?Resource near load centersMinimize greenhouse gas emissions from electricity generationMinimal water consumption for electricity generationEnergy IndependenceGreen Jobs and local economic development

Higher Capacity FactorsLow shear and turbulenceHigher wind speedsTurbines can spin at higher tip speeds and hence higher energy production

A POWERFUL RESOURCE IN US

WHY LARGER TURBINES?

CHALLENGES and OPPORTUNITIESRotor Blade StructureNew materialsTwo-pieceLarger Chords

New Tower conceptsComposite materialsLighter and corrosion resistanceDrivetrainDirect drive or low speed

Foundations

Corrosion protection

Site specific wind data collection and correlation with mesoscale weather prediction models for wind assessment.Further research and data collection using newer offshore friendly technology like LIDAR, SODAR etc is very important

Demonstration platforms or prototype farms are required for offshore wind specific technology development and long term cost competitiveness of offshore wind. This is similar to land based turbine testing at NREL and UKs (public-private) initiative to have 100MW offshore wind farm available for prototyping and testing.

CHALLENGES and OPPORTUNITIES

Static strength testing and accelerated fatigue testing of wind turbine blades are required for Turbine certification Reduce the risk of widespread failuresImprove blade reliabilityReduce COEBlades over 50m can not be fatigue tested in the United StatesBlades 62m long are in production and longer blades are being designedThis project will reduce COE by Reducing frequency of blade failuresLowering machine costIntroducing more efficient bladesReducing technical and financial risk of large-scale deploymentProviding industry with low cost test facilities to comply with certification requirements and support value engineering

BLADES - Statement of the ProblemSlide courtesy of Jason Cotrell of NREL

Chart3

91989

199319

1934

241999

372002

50.752004

200550

61.52006

NWTC IUF Blade Test Facility built for blades up to 34m

NWTC Blade Test Facility modified to test blades up to 50m

.1 MW

.5 MW

.75 MW

3.6 MW

5 MW

1.5 MW

7 MW Clipper Offshore)

Blade Length (m)

Sheet1

Onshore Blade LengthOnshore Rating (MW)Offshore Blade LengthOffshore Rating (MW)Onshore & Offshore Blade LengthsBlade Test FacilitiesLM

198990.190.1198814.5

199319251

1996190.5190.534IUF199821

1999240.75240.75200233

2002371.5371.5200462.5

2004452.5513.6512.5

200550IUF

2006625625

PROJECTIONS

402.1151431027

503.3049110979

604.759071981

706.4776257519

808.4605724106

9010.7079119572

10013.2196443916

Sheet1

NWTC IUF Blade Test Facility built for blades up to 34m

NWTC Blade Test Facility modified to test blades up to 50m

.1 MW

.5 MW

.75 MW

3.6 MW

5 MW

1.5 MW

7 MW Clipper Offshore)

Blade Length (m)

Sheet2

NWTC IUF Blade Test Facility built for blades up to 34m

NWTC Blade Test Facility modified to test blades up to 50m

.1 MW

.5 MW

.75 MW MW

3.6 MW

5 MW

1.5 MW

Blade Length (m)

Sheet3

Development of Test EquipmentProcuring a state of the art hydraulic based static test system from MTSWorking with MTS to scale up NREL UREX Fatigue Test SystemDesigning and procuring a new generation of the NREL data acquisition hardwareDeveloping a new version of data acquisition software

Schematic of MTS Static Test SystemCourtesy of MTS websiteTechnical ApproachSlide courtesy of Jason Cotrell of NREL

Picture courtesy of MTS and NRELStatic and Fatigue TestingLatest hydraulic actuators/winches will allow matching various specified bending moment distributions.

Dual-axis resonant test system (NREL patent pending)

THANK YOU

*****