Offshore Wind Walt Musial Power and the Manager Offshore Wind Challenges of and Ocean Power Systems Large Scale National Renewable Energy Laboratory Deployment

Inaugural Meeting of the North American Wind Energy Academy

August 7th - 9th, 2012 Photo: Baltic I – Wind Plant University of Massachusetts Amherst Germany 2010 Credit: Fort Felker William E. Heronemus University of Massachusetts Circa 1973

UMass has Pioneered Offshore Wind Energy • 51 projects, 3,620 MW installed (end of 2011)

• 49 in shallow water <30m

• 2-5 MW upwind rotor configuration (3.8 MW ave) • 80+ meter towers on monopoles 2.0 MW Turbine Horns Rev, DK • Modular geared drivetrains • Marine technologies for at sea operation. • Submarine cable technology • Oil and gas experience essential • Capacity Factors 40% or more

• Higher Cost and O&M have contributed to project risk.

Alpha Ventus – RePower Siemens 2.0 MW Turbines 5-MW Turbine Middlegrunden, DK 3 National Renewable Energy Laboratory Offshore Wind Projects Cumulative And Annual Installation; The U.K. And Denmark Account For Nearly 75% Of Capacity

1,600 4,000

1,400 3,500

1,200 3,000 (MW)

(MW) 1,000 2,500 Capacity Capacity 800 2,000 Installed

Installed

600 1,500 Annual Cumulative 400 1,000

200 500

‐ ‐ 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Offshore Wind Power 4 National Renewable Energy Laboratory Offshore Wind Projects Installed, Under Construction, and Approved 30 25,585 MW 25

20 (GW)

15 Capacity 10 3,500 MW

5 3,620 MW

0 Installed Under Construction Approved Offshore Market Is Becoming Increasingly Diversified

Fuji Heavy Shanghai Electric GE 1% 0% 0% 1% WinWind 1% BARD China Energine 2% 0% 0% Iberdrola 3% Mingyang vel 3% 0% 0% Goldwind % Repower 2% 6%

BARD 11%

Projected Siemens Installed Capacity Siemens Near-Term Capacity* 44% ~3,620 MW 48% Areva 15%

Vestas 39% Sinovel 5% Vestas Repower 10% 6%

* Includes projects under construction and approved projects that have announced a turbine manufacturer 6 Installed capital costs have increased substantially from 2005 levels

Weighted-average cost of planned offshore wind projects = $4,862/kW Offshore Wind Cost of Energy Reduction

Scale of Global Deployment Risk Reduction Technology Innovation • Learning Curve • Permitting • Turbine Optimization • Volume Production • Construction Delays • Balance of Station • Supply Chain Maturity • Ops – Reliability & Production • Offshore Grid • Deployment and Field • Financial and Market • Array optimization Experience Uncertainty • Integration

Initial Cost

Scale

Risk

Mature Technology Market Cost

Present Year Time Installed capital costs for offshore wind turbines Turbines account for only 32% of ICC

9 Larger scale is needed to achieve lower offshore wind cost

Larger Turbine Sizes Large Scale Increased Wind Deployment Plant Sizes Capacity (MW) 100 10 20 30 40 50 60 70 80 90 0 National deploymenttargets in the E.U., U.S., and Chinacall Offshore Wind Offshore Wind Power 0.1 for ~86 GW of offshore wind to be installed by 2020 for ~86GW of offshore windtobeinstalled 0.1 0.2 0.2 0.3 0.3 0.5 0.6 11 0.7 1.3 3.0 5.2 EU 6.0 National RenewableEnergy Laboratory USA 10.0 China 18.0 46.3 10.0 30.0 86.3 Offshore Wind Technology is Depth Dependent

Offshore Wind Power 12 National Renewable Energy Laboratory Depth (m) hi 200 210 220 ‐ Near-term offshorewindprojectswillbeinstalled indeeper Offshore Wind Offshore Wind Power 10 10 20 30 40 50 60 0 0 2 Near-shore 0 waters andfurtherfromshore Project Installed Bubble size represents project capacity Bubble 4 0 Distance 13 Construction Under 6 (DC power export technology becomes exporttechnology power competitive)(DC 0

to Shore (km) 8 0 Project Approved Far-shore National RenewableEnergy Laboratory

1 0 0 Transitional Water Shallow Water Shallow Deep Water 1 2 0 Depth (m) hi 200 210 220 ‐ Near-term offshorewindprojectswillbeinstalled indeeper Offshore Wind Offshore Wind Power 10 10 20 30 40 50 60 0 0 2 Near-shore 0 waters andfurtherfromshore Project Installed Bubble size represents project capacity Bubble 4 0 Distance 14 Construction Under 6 (DC power export technology becomes exporttechnology power competitive)(DC 0

to Shore (km) 8 0 Project Approved Far-shore National RenewableEnergy Laboratory

1 0 0 Transitional Water Shallow Water Shallow Deep Water 1 2 0 Depth (m) hi 200 210 220 ‐ Near-term offshorewindprojectswillbeinstalled indeeper Offshore Wind Offshore Wind Power 10 10 20 30 40 50 60 0 0 Wind Cape 2 Near-shore 0 waters andfurtherfromshore Project Installed Bubble size represents project capacity Bubble 4 0 Distance 15 Construction Under 6 (DC power export technology becomes exporttechnology power competitive)(DC 0

to Shore (km) 8 0 Project Approved Far-shore National RenewableEnergy Laboratory

1 0 0 Transitional Water Shallow Water Shallow Deep Water 1 2 0 Depth (m) hi 200 210 220 ‐ Near-term offshorewindprojectswillbeinstalled indeeper Offshore Wind Offshore Wind Power 10 10 20 30 40 50 60 0 0 Wind Cape 2 Near-shore 0 Demonstration Projects Floating Technology waters andfurtherfromshore Project Installed Bubble size represents project capacity Bubble 4 0

Distance 16 Construction Under 6 (DC power export technology becomes exporttechnology power competitive)(DC 0

to Shore (km) 8 0 Project Approved Far-shore National RenewableEnergy Laboratory

1 0 0 Transitional Water Shallow Water Shallow Deep Water 1 2 0 Common Foundation Types Used in Shallow Water (0-30m depths)

Monopiles Gravity Base 73% of Current Installations 21% of Current Installations

Offshore Wind Power 17 National Renewable Energy Laboratory Cape Wind 468-MW Wind Plant - Massachusetts

Location: Nantucket Sound, MA Turbine Size/Description: 130 Siemens 3.6 MW wind turbines

Expected Deployment 2013 Date : Foundation Type: Monopiles Average distance from 9.5 miles shore Average Water Depth 11-m Expected Energy 1.5 Billion KWh/yr production Approximate Budget: $ 2.6 B USD

The Cape Wind project is the first and only offshore wind project to receive a license to begin construction in U.S. federal waters The project will produce 75% of the electricity for Cape Cod and the Islands. Transitional Water Depths Need Multi-pile Support Structures (30-60m)

Tripod Type Jacket or Truss Type

Offshore Wind Power 19 National Renewable Energy Laboratory Multi-pile foundation designs are gaining market share as larger turbines are installed in deeper water

5.3% 1.0% 0.3% 0.1%

28.9% 20.9%

Installed Capacity Projected ~3,620 MW Near-Term Capacity* ~10,070 MW 58.0%

12.8% 72.7%

Gravity bases are not represented in the near-term plans of developers

* Includes projects under construction and approved projects that have announced a foundation design 20 Turbine Scaling Trend Based on Current Installations: Generator size, rotor diameter, and hub height are increasing 10.0 130 Weighted Average Capacity (right axis)

9.0 Individual Project Capacity (left axis) Weighted Average Rotor Diameter (right axis) 110

8.0 Weighted Average Hub Height (right axis)

90 7.0 (m)

6.0 Height 70 (MW) Hub 5.0 and

50 Capacity 4.0 Diameter

Rated 3.0 30 Rotor

2.0

10 1.0

0.5 0.5 0.5 0.6 0.6 2.0 1.9 2.0 2.2 2.5 3.0 3.0 3.0 3.2 2.8 3.1 3.9 3.9 4.1 4.2 4.9 0.0 (10) 1990 1995 2000 2005 2010 2015 Offshore Wind Power 21 National Renewable Energy Laboratory Offshore Turbines Sizes are Expected To Continue To Grow

Source : Jos Beurskens - ECN Netherlands Offshore Wind Power 22 National Renewable Energy Laboratory Large Offshore Turbine Technology (5-10 MW)

Challenges • Mass scaling laws limit conventional designs • Installation vessel capacity limits design options • Composite technology for large machines is unproven

Enabling technologies for large machines • Ultra-long blades/rotors • Downwind rotors • Direct drive-generators (possible HTSC) • High reliability integrated systems • Innovative deployment systems • Special purpose vessels

Offshore Wind Power 23 National Renewable Energy Laboratory Blade Scaling Critical for Large Turbines The need for larger blades is driving advanced material, manufacturing, and design innovations

Commercial Wind Turbine Blade Weights

50,000 Historic trend y = 1.5336x2.3183 OfO Onshore

40,000 f fshore Bladesfsho

30,000 re Blades Blad Quadratic Scaling Can this be achieved?

20,000 es

10,000 Approx Blade Weight (kg) Weight Blade Approx 0 0 20 40 60 80 100 Blade Length (meters)

Offshore Wind Power 24 National Renewable Energy Laboratory Offshore Trend Toward Direct Drive Generators

Goldwind

Graphic: Courtesy of American Superconductor

• Conventional gear driven turbines offered lightest and lowest cost but have had suffered high maintenance costs • Direct drive generators (DDG) promise higher reliability due to fewer moving parts • New designs promise lighter weight • Most OEMs are developing 5-7MW class DDGs wind turbine (or medium speed) Siemens Wind Power Offshore Wind Power 25 National Renewable Energy Laboratory Electric Grid and System Integration

Challenges • 54-GW by 2030 of Offshore Wind • Constrained land-based grid in high population density coastal regions • Variable power delivery and establishing capacity value • Up to 80% of Offshore Insurance claims New Offshore Grid Technologies • Offshore backbones for power delivery • HVDC for long distance power Proposed Super-grid for European Offshore Wind • Aggregate offshore wind plants • Cable protocols

HVDC Power Networks Credit: KEMA Baltic 1 Substation Offshore Wind Power 26 National Renewable Energy Laboratory Offshore Metocean Characterization Tools Challenges • High cost of MET masts has inhibited widespread metocean characterization • Marine boundary layer (wind shear, stability, and turbulence) is not well characterized • Resource assessments rely on sparse measurements for validation • External design conditions for turbines are not well understood Floating wind LIDAR; The Natural Power Sea ZephIR (from http://blog.lidarnews.com)

New Technology for Metocean Characterization: • Remote sensing (LIDAR, SODAR) • Measurement campaigns for metocean conditions at hub height • Improved weather models • Integration of multiple data sources for validation (e.g. satellites, met towers) • Improved forecasting

Offshore Wind Power 27 National Renewable Energy Laboratory OFFSHORE WIND ARRAY EFFECTS

Offshore Wind Power 28 National Renewable Energy Laboratory Offshore Wind Turbines in Atlantic and GOM Must be Designed for Hurricanes

• Wind Turbines are often Type Certified before site conditions are known • High uncertainty in predicting hurricane probability and intensity • U.S. Hurricane conditions can exceed IEC Class 1A wind specifications • New Standards and Protocols will address Hurricane Design

Table 1. Saffir/Simpson Hurricane Scale, modifed from Simpson (1974).

Typical characteristics of hurricanes by category Scale Number Winds (Category) (Mph) (Millibars) (Inches) Surge (Feet) Damage

1 74-95 > 979 > 28.91 4 to 5 Minimal

2 96-110 965-979 28.50-28.91 6 to 8 Moderate

3 111-130 945-964 27.91-28.47 9 to 12 Extensive

4 131-155 920-944 27.17-27.88 13 to 18 Extreme

5 > 155 < 920 < 27.17 > 18 Catastrophic

Offshore Wind Power 29 National Renewable Energy Laboratory Breaking Waves: A potential design driver

• Breaking waves can occur when wave height approaches water depth (critical at some locations)

• Design must consider occurrence during extreme 50/100 year return storms

IEC 61400-3 • Breaking waves can double the Breaking load magnitude Wave Model is not • Validation data is needed to validated improve and validate the model. where: C = wave celerity

Hb = wave height at the breaking location b = maximum elevation of the free water surface R = radius of the cylinder  = curling factor  0,5 Offshore Wind Power 30 National Renewable Energy Laboratory Ice Loading Design and Mitigation

Induced Mechanical Vibration Resonant Frequency Shift Ice Force •Thickness •Strength •Velocity •Fracture Mode

Baltic Sea – Windpower Monthly Cover Photo Feb 2003 Excitation Lock-in

Wind Turbines at Nysted with Ice Cones

Base Load Force

Offshore Wind Power 31 National Renewable Energy Laboratory SPAR BARGE TENSION LEG PLATFORM

Offshore Wind Power 32 National Renewable Energy Laboratory Floating Offshore Wind Turbines

Graphic: Glosten Photo: Principle Photo: Hywind/Statoil Associates, PELESTAR Power Inc. SPAR TLP SEMI- SUBMERSIBLE Summary of Challenges and Opportunities

• Initial costs are high due to smaller scales, higher risk, and immature technology • Global scale deployment is needed for cost reduction • Stable policy incentives are needed to offset first adopter cost challenges • Technology innovations are needed to lower cost and expand siting options • Unique environmental conditions require optimized turbine designs • Mature costs realized through scale and innovation. Offshore Wind Power 35 National Renewable Energy Laboratory