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

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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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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)

EW 1.5 MW

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