Walt Musial
Manager Offshore Wind and
Ocean Power Systems
National Renewable Energy Laboratory
National Oceans Science Bowl Photo: Baltic I – Wind Plant December 19, 2011 Germany 2010 Credit: Fort Felker National Wind Technology Center Overview
• Turbine testing since 1977 • Modern utility-scale turbines • Leader in development of design and • Approx. 150 staff on-site analysis codes • Budget approx. $40M • Pioneers in component testing • Partnerships with industry • Unique test facilities • Leadership roles for international • Blade Testing standards • Dynamometer drivetrain testing • Marine Hydrokinetic Technology • Controls research turbines (CART)
Offshore Wind Power 2 National Renewable Energy Laboratory National Wind Technology Center Overview
DOE 1.5 MW
Siemens 2.3 MW
Alstom 3 MW
Gamesa 2 MW
Offshore Wind Power 3 National Renewable Energy Laboratory Renewable Energy Provides 80% Electricity Under Proactive Deployment Scenario (Preliminary results from DOE renewable electric futures study 2011 )
1600 Storage
1400 Offshore Wind Onshore Wind 1200 Distributed PV Utility PV 1000 CSP 800 Hydropower Geothermal 600
Ded. Biomass Installed Capacity (GW) Capacity Installed 400 Cofire Biomass Natural Gas 200 Cofire Coal Coal 0
Nuclear
2010 2014 2018 2022 2026 2030 2034 2038 2042 2046 2050
Offshore Wind Power 4 National Renewable Energy Laboratory Wind Energy Technology
At it’s simplest, the wind turns the turbine’s blades, which spin a shaft connected to a generator that makes electricity. Large turbines can be grouped together to form a wind power plant, which feeds power to the electrical transmission system. A Few Basic Wind Energy Rules
Power in the wind is proportional to the area swept by the rotor
Power in the wind is proportional to the wind velocity cubed.
A wind turbine cannot extract more than 59% of the energy in the wind stream. SWEPT AREA Wind Turbine Power Curve
Power in the Wind = 1/2AV 3 Land Based Technology
GE 1.5-MW 77-m Land-based Utility Technology GE diameter1.5-MW 77-m diameter • 1.5 – 3.0 MW • Three bladed Vestas V-90 • Upwind Horizontal Axis Configuration • 80 – 100 Meter Tube Tower • Three stage gearbox; Multi-generator; & Direct Drive Designs • Full Span Pitch Control • Advanced Controls Systems • Variable speed with full electric Power conversion Performance • 98% Availability • 1-MW supports about 300 homes Vestas V120 4.5-MW • 32% Capacity Factor Clipper 2.5 MW Prototype – ClipperMedicine 2.5 Bow MW WY Prototype – • Improvements Needed in O&M & Medicine93-m diameter Bow WY Gearbox Reliability 93-m diameter • 51 projects, 3,620 MW installed
• 49 in shallow water <30m
• 3-5 MW upwind configuration (3.8 MW ave) • 80+ meter towers on
Vestas 2.0 MW Turbine monopoles Horns Rev, DK • Marine technologies for at sea operation. • Submarine cable technology • Oil and gas experience essential • Capacity Factors average 40%
• Cost and Reliability on early projects have contributed to uncertainty in development. Gravity Based Foundations Seimens 2.0 MW Turbines in Baltic Nysted Middlegrunden, DK Offshore Wind Power 9 National Renewable Energy Laboratory 12 countries have installed offshore wind projects to date; the U.K. and Denmark account for nearly 75% of capacity 1,600 4,000
1,400 3,500
1,200 3,000
1,000 2,500
800 2,000
600 1,500
Annual Installed Capacity (MW) Capacity Installed Annual Cumulative Installed Capacity (MW) Capacity Installed Cumulative 400 1,000
200 500
- - 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Offshore Wind Power 10 National Renewable Energy Laboratory National deployment targets in the E.U., U.S., and China call for ~86 GW of offshore wind to be installed by 2020 100
90 30.0 86.3
80
70
60 10.0
50 18.0 46.3
40 Capacity (MW) Capacity
30 10.0
20 6.0 5.2 10 3.0 0.7 1.3 0.1 0.1 0.2 0.2 0.3 0.3 0.5 0.6 0
Offshore Wind Power 11 National Renewable Energy Laboratory Offshore Wind Technology is Depth Dependent
Offshore Wind Power 12 National Renewable Energy Laboratory Near-term offshore wind projects will be installed in deeper waters and further from shore Near-shore Far-shore (DC power export technology becomes competitive)
220 hi 210 Deep Water
200
60
50
Depth (m) Depth Transitional Water 40
30
20
Shallow Water 10
0 0 20 40 60 80 100 120 Distance to Shore (km) -10 Installed Under Approved Project Construction Project Bubble size represents project capacity Offshore Wind Power 13 National Renewable Energy Laboratory 13 Near-term offshore wind projects will be installed in deeper waters and further from shore Near-shore Far-shore (DC power export technology becomes competitive)
220 hi 210 Deep Water
200
60
50
Depth (m) Depth Transitional Water 40
30
20
Shallow Water 10
0 0 20 40 60 80 100 120 Distance to Shore (km) -10 Installed Under Approved Project Construction Project Bubble size represents project capacity Offshore Wind Power 14 National Renewable Energy Laboratory 14 Near-term offshore wind projects will be installed in deeper waters and further from shore Near-shore Far-shore (DC power export technology becomes competitive)
220 hi 210 Deep Water
200
60
50
Depth (m) Depth Transitional Water 40
30
20
Shallow Water 10
0 0 20 40 60 80 100 120 Distance to Shore (km) -10 Installed Under Approved Project Construction Project Bubble size represents project capacity Offshore Wind Power 15 National Renewable Energy Laboratory 15 Near-term offshore wind projects will be installed in deeper waters and further from shore Near-shore Far-shore (DC power export technology becomes competitive) 220 Floating Technology
Demonstration Projects hi 210 Deep Water
200
60
50
Depth (m) Depth Transitional Water 40
30
20
Shallow Water 10 Cape Wind
0 0 20 40 60 80 100 120 Distance to Shore (km) -10 Installed Under Approved Project Construction Project Bubble size represents project capacity Offshore Wind Power 16 National Renewable Energy Laboratory 16 Horns Rev Wind Farm Shallow Water
Offshore Wind Power 17 National Renewable Energy Laboratory Shallow Water (0-30m depths) Foundation Types
Monopile Gravity Base
Offshore Wind Power 18 National Renewable Energy Laboratory Transitional Water (30-60m depth) Foundation Types
Tripod Type Jacket or Truss Type
Offshore Wind Power 19 National Renewable Energy Laboratory What is the situation in the United States? Offshore Wind Resource is Near Load Centers
55 million people in NE 18% of US population Highest electricity costs
21 Offshore Wind Power 21 National Renewable Energy Laboratory USDOE Program Goal: 20% Wind Electricity with 54-GW from Offshore
300 Offshore 54-GW of Land-based Offshore 250
200
150
100 20% Wind Scenario 50
Actual Cumulative Installed Capacity (GW) Capacity Installed Cumulative
0 2000 2006 2012 2018 2024 2030 Offshore Wind Power 22 National Renewable Energy Laboratory To date, no offshore wind projects have been installed in the U.S., but several projects are making significant progress
Three projects have signed Power Purchase Agreements with utilities • EMI and National Grid for 264 MWs of at the Cape Wind project • Deepwater Wind and National Grid for 29 MW at the Block Island Wind Farm • NRG Bluewater Wind and Delmarva for 200 MWs at Delaware’s Offshore Wind Park Offshore Wind Power 23 National Renewable Energy Laboratory U.S. Offshore Wind Resource by Distance from Shore
3,000,000 GROSS OFFSHORE OUTER CONTINENTAL SHELF RESOURCE RESOURCE AREA 0-50 NM CAPACITY IN USA 2,500,000 (MW)
2,000,000
1,500,000
1,000,000
Wind Resource Capacity (MegaWatts) Capacity Resource Wind 500,000
0 0 - 3 nm 3 - 12 nm 12 - 50 nm Distance from Shore (Nautical Miles) Offshore Wind Power 24 National Renewable Energy Laboratory Offshore Wind Technology Challenges Offshore Turbines Continue to Grow
Source : Jos Beurskens - ECN Netherlands Offshore Wind Power 26 National Renewable Energy Laboratory Average offshore wind turbine capacities, rotor diameters, and hub heights are expected to continue to increase 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
6.0 70
5.0
50
4.0 Rated Capacity (MW) Capacity Rated 3.0
30 Rotor Diameter and Hub Height (m Height and Hub Diameter 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 27 National Renewable Energy Laboratory 27 Large Offshore Turbine Technology (5-10 MW)
Challenges • Offshore economics favor larger machines but technology for large machines needs to be developed • O&M costs, electric distribution costs, specific energy production, installation cost, foundations costs - all improve with turbine size • Vessels for installation and service are limited
Solutions • Enabling technologies for large machines • Innovative deployment systems • Ultra-long blades/rotors • Down wind rotors • Direct drive-generators (possible HTSC) • Optimized offshore wind turbines • High reliability systems and components • Weight optimized floating wind turbines • Special purpose vessels
Offshore Wind Power 28 National Renewable Energy Laboratory Blade Scaling is Critical for New Offshore 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 Offshore Blades 40,000 Onshore
30,000
Blades Quadratic Scaling Can this be achieved?
20,000
10,000 ApproxBlade Weight(kg) 0 0 20 40 60 80 100 Blade Length (meters) Offshore Wind Power 29 National Renewable Energy Laboratory Offshore Trend Toward Direct Drive Generators
Goldwind
Graphic: Courtesy of American Superconductor
• Geared drivetrain failures contribute to O&M costs • Direct drive generators (DDG) promise higher reliability due to fewer moving parts • Gear driven turbines have the lowest weight and initial cost but have had poor reliability • Current DDG designs are heavy • Lower weight (hence cost) DDG are sought by most major turbine manufacturers today
Siemens Wind Power Offshore Wind Power 30 National Renewable Energy Laboratory Electric Grid and System Integration
Challenges • 54-GW by 2030 of Offshore Wind. • Over 100 large wind power facilities • Land-based grid expansion is constrained – especially in high population density coastal regions Solutions • Offshore backbones for power delivery • HVDC technology • Aggregate offshore wind plants Proposed Super-grid for European Offshore Wind
HVDC Power Networks Credit: KEMA
Baltic 1 Substation Offshore Wind Power 31 National Renewable Energy Laboratory Offshore MET/Ocean Characterization Tools Challenges • High cost of MET masts has inhibited accurate 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 poorly understood Floating wind LIDAR; The Natural Power Sea ZephIR (from http://blog.lidarnews.com)
Solutions: • Remote sensing systems (LIDAR, SODAR) • R&D to measure metocean conditions at sea • Improved weather models • Integration of multiple source data to validate resource models (e.g. satellites, met towers, etc) • Improved forecasting Offshore Wind Power 32 National Renewable Energy Laboratory OFFSHORE WIND ARRAY EFFECTS
Offshore Wind Power 33 National Renewable Energy Laboratory Offshore Wind Turbines in the U.S. May Experience Hurricanes
• Wind Turbines are often Type Certified before site conditions are known • U.S. Hurricane conditions can exceed IEC Class 1A wind specifications • High uncertainty in predicting hurricane probability and intensity • Data is needed to characterize hurricane conditions at hub height
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 34 National Renewable Energy Laboratory Breaking Waves: A potential design driver
• Breaking waves can occur when wave height approaches water depth
• Design must consider occurrence during extreme 50/100 year return storms IEC 61400-3 Breaking • Breaking waves can double the Wave Model load magnitude is not validated • Validation data is needed to 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 35 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 36 National Renewable Energy Laboratory SPARS TENSION LEG BARGES PLATFORMS
Offshore Wind Power 37 National Renewable Energy Laboratory Static Stability Triangle for Floating Wind Turbine Systems
SPARS Ballast Stabilized
(Statoil Spar Buoy) (SWAY Spar Buoy)
(HiPRwind Semisubmersible)
(ITI Barge) (DeepCwind TLP)
Buoyancy Mooring Line Stabilized Stabilized (Principle Power (Water Plain Area) TENSION LEG WindFloat) BARGES PLATFORMS Key Demonstration Projects Plotted- 2011
Offshore Wind Power 38 National Renewable Energy Laboratory World’s First Floating Wind Turbine
Siemens SWT-2.3 MW • R&D Project developed by Hywind StatoilHydro, and Siemens • 12 km southeast of Karmøy in Norway • SWT - 2.3 MW architecture 82 meter diameter 65 meter tower • Spar buoy technology 100 meter draft 202 meter water depth Reference: w1.siemens.com
Image Credit: www.greenlaunches.comNational Renewable Energy Laboratory Innovation for Our Energy Future
Offshore Wind Power 39 National Renewable Energy Laboratory The Next Big Industrial Transformation will be in the way that we generate, store, transmit, distribute, and save energy
Wind Solar PV Concentrating Solar Biofuels Renewable Energy Geothermal Waterpower
Buildings Load management Lighting Smart Load control Vehicles Energy Grid and Distributed generation Industry Efficiency Load Grid expansion Control Appliance System reliability Transmission
Transportation and Energy Storage EV Battery Storage Vehicle to Grid Battery Aggregation Grid firming for variable power
Offshore Wind Power 40 National Renewable Energy Laboratory Offshore Wind Power 41 National Renewable Energy Laboratory