Wind Energy Overview:
Technology, Economics and Future Evolution
Brian SmithTeam Leader, Turbine DevelopmentNational Wind Technology Center
May 8, 2002
Growth of Wind Energy Capacity Worldwide
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86 87 88 89 90 91 92 93 94 95 96 97 98 99 2000 2001 2002 2003 2004 2005
MW
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talle
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Jan 2002 Cumulative MW
Rest of World = 2,365
North America = 4,543
Europe = 16,362
Sources: BTM Consult Aps, March 2001
Windpower Monthly, January 2002
Actual Projected
Rest of World Rest of World
North America North America
Europe Europe
International Market Drivers
• Europe– high mandated purchase rates (85-90% of retail, 10-12 cents/kWh)– strong government and public commitment to the environment,
including climate change– population density & existing developments driving off shore
deployment in Europe
• Developing World– huge capacity needs– lack of existing infrastructure
(grid)– pressure for sustainable
development (IDB’s, climate change)
– tied aid
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.
Sizes and Applications
Small (10 kW)• Homes• Farms• Remote Applications
(e.g. water pumping, telecom sites, icemaking)
Intermediate (10-250 kW)• Village Power• Hybrid Systems• Distributed Power
Large (250 kW - 2+MW)• Central Station Wind Farms
• Distributed Power
Cost of Energy Trend
1979: 40 cents/kWh
• Increased Turbine Size
• R&D Advances
• Manufacturing Improvements
NSP 107 MW Lake Benton wind farm4 cents/kWh (unsubsidized)
2004: 3 - 5 cents/kWh
2000:4 - 6 cents/kWh
Finances and Incentives
• Current Situation Wind energy viable at higher wind speed sites
(Class 6 – 15 mph annual average @ 10m) Limited high wind sites in U.S. Subsidies important to compete
• Production Tax Credit 1.7 cents/kWh (escalating) for 10 years
(~ 1.1 cent/kWh reduction in contract price) deadline pressure increases costs
• State and Local tax can be significant +/- 0.5 cents/kWh impact
NREL’s National Wind Technology Center Research and Development
EW 1.5 MW Drive Train35 Meter Blade Strength Test
NASA Ames 80’X 120’ Wind TunnelYaw angle = 30°
2-D Dynamic Stall
• Basic & Applied Research• World-Class Testing Facilities
• Advanced Prototype Development
Wind Resource Mapping
• Identifies most promising areas for wind energy development
• Employs geographic information system technology to create layers of key information
• Used by state energy planners, Indian tribes, and developers
• Approach changing from empirical to numerical modeling techniques
• Forecasting, resource assessment and site specific inflow quantification methods are likely to converge into a single approach
Unsteady Aerodynamics Experiment
• Predicting the aerodynamic loads on wind turbines remains the greatest technical challenge:
- Wind is unsteady and three-dimensional.
- Rapid changes in direction & magnitude force different flow conditions (stall, skewed flow, shear, etc.)
- These conditions are unlike anything experienced by aircraft or helicopters.
• Completed joint program with NASA Ames in the 80’ x 120’ wind tunnel to resolve these aerodynamic effects.
• Results obtained will provide the benchmark data for aerodynamic code development and advanced blade concepts for the next 5-10 years.
Hybrid Systems Development
Wales, Alaska Control System Installation
Staff are currently in Wales installing innovative, high penetration control system for the wind/storage/diesel power supply system.
• Investigate problems associated with integrating multiple generation & energy storage devices-wind -diesel generation -fly wheels-PV -micro-turbines -batteries
• Develop new control strategies to optimize hybrid operation using multiple hardware components
• Test operation of user hardware in on & off line hybrid environment.
• water pumping• battery charging• power conversion• ice making• refrigeration
NREL’s Component Testing Facilities
• NREL operates the only full-scale blade testing facility in the U.S. for MW-scale wind turbines.
• NREL operates the only facility in the world for full-system wind turbine drive train testing.
• Both facilities are currently operating at maximum capacity.
• Larger facilities are necessary to support the development of new low wind speed technology:– 5-MW designs under development– GE/Enron Wind 3.6 MW prototype is
built and ready to test
34-Meter Blade Test at Industrial User Facility
750-kW Drive train test in 2.5-MW Dynamometer Test Facility
Wind Integration Monitoring & Analysis
Lake Benton and Storm Lake10-minute Average Power
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1/1/01~1/7/01
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Storm Lake Lake Benton
Wind integration barriers: • Fluctuating wind outputs raise
concern about system stability and ancillary costs
• Wind cannot be controlled or dispatched
Research needs:• Monitor windfarm output to
measure the fluctuations, and access ancillary impacts and costs
• Assist utilities develop better models of windfarm electrical output for planning, operations, and transmission requirements
• Provide technical support to utility staff developing and planning for wind integration
• Support the improvement of forecasting techniques to predict output
Challenging DOE Program Goals
Low Wind Speed Technology
Develop wind turbine technology (>100kW) capable of 3 cents/kWh in Class 4 (13.4 mph wind site) by 2010• Increase area available for wind energy development by
a factor of 20 or more
• Accelerate achievement of the domestic renewable energy generations capacity goal
Distributed Wind Systems
• Reduce the cost of energy from distributed wind systems to $.10-$.15/kWh at Class 3 wind sites (12 mph wind site) by 2007
• Increase distributed energy capacity in the United States
Transmission Line230 KV and greaterMajor Load Center
Wind Power Classification
•13-14
•15+
•Good/Excellent
•Outstanding
•4-5
•6
•Wind Speed at 10 m (mph)•Resource Potential•Wind Power Class
Wind Resource Class Comparison
Baseline (15 GW in 2020)• No technology breakthrough• Class 6 Plateau
Expands resource base 20-fold Reduces average distance to load 5-fold 35 GW additional opportunity by 2020
Program Goal: 3 cents/kWh Class 4 COE in 2010
Benefits of Low Wind Speed Technology to U.S. Industry
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2005 2010 2015 2020
GW Competitive Class 4 Technology*
*Growth trajectory from NEMS using AEO 2001 assumptions with 3 cent/Class4/2007 technology
EIA/AEO 2001 Renewables Cases
Opportunity
2001
Reference
High Renewables
Turbines Under Development with IndustryH
eigh
t in
met
ers
WindLiteCorporation
SouthwestWindPower
BergeyWindpower
AtlanticOrient
Corporation
NorthernPower
SystemsEnron WindCorporation
Enron WindCorporation
WindTurbine
Company
Rated Power(kW)
10 5 50 50 100 750 1500 750
Rotor Diameter(m)
7 5 14 15 19 50 77 55
Number ofBlades
3 3 3 3 3 3 3 2
Prototype Year 2002 2002 2001 1999 2001 1999 2002 2001
Hei
ght i
n m
eter
s
Turbine Research Prototypes
EW 750i (NTRT)
AOC 15/50 (NTPT)NPS NW 100 (CWT)
WTC 500 kW EMD-1 (NGT) EW 1.5 MW POC (NGT)
Bergey XL.50 (SWT)
Technology Challenges – Very Tall Towers
Vestas V66 on 117 m tower
•Steel tube•Truss towers•Pre-stressed concrete•Composite•Hybrid towers•Self-erecting/no cranes
Tall Tower Concepts:(85 – 120 m, 280 – 400 ft)
Development Challenges:
•Weight and cost•Shipping•On site manufacturing•Fatigue loading•Tower load feedback control•Foundation cost
Source: Multibrid Technology Brochure
Generator and Single Stage Gearbox Integrated Low Speed
Technology Challenges – 5 MW Drive Train
A Future Vision for Wind Energy
2002Maturing Technology
Bulk Power Generator
4-6¢ at 15mph
Land Based
Bulk Electricity
Wind Farms
Potential 20% of Electricity Market
Business as Usual PathTransmission
Barriers
Regulatory Barriers
Land & OceanLarge & Small• Electricity• Electrolysis• H2
Cost & Infrastructure Barriers
Land Based LWSTMid-West Plains
Offshore WindOcean Based LWST
5MW ScaleCoastal Markets
FutureLow Wind Speed
Technology3¢/kWh at 13mph20% of Electricity
High Probability of Success
2010
Low Wind Speed Technology Offshore
?¢/kWh at 13mph20% of Electricity
2010
Wind-H2 Technology•Transportation•Firm Electricity•Industrial•ResidentialUnlimited Market2030 & Beyond
Offshore Path
Wind-Hydrogen Path