wind energy: status, challenges, opportunities · mission statement: support the development of...

1Wind Energy OverviewWind Energy Overview

Wind Energy:Wind Energy:Status,Status,Challenges,Challenges,OpportunitiesOpportunities

C.P. C.P. ““CaseCase”” van Dam van Damcpvandam@[email protected]

NASA Internal Workshop on WindPower Capabilities

March18, 2010


OutlineOutline

• Background

• Why Wind Energy?

• Wind Energy– Status

– Challenges

– Opportunities

Source: Mayda


California Wind EnergyCalifornia Wind EnergyCollaborativeCollaborative

Mission Statement:Support the development of safe,reliable, environmentally sound,and affordable wind electricgeneration capacity within thestate of California by managing afocused, statewide program ofscientific research, technologydevelopment & deployment, andtechnical training.

CALIFORNIAWIND ENERGY

COLLABORATIVE

CaliforniaEnergy

Commission

Federal, state, andlocal government

agencies

Academia

Industry

Publicprograms

Government andindustry research

labs

Education&

Outreach

EngineeringResearch

Inter-agency,Inter-sector

Coordination

• A partnership of theCalifornia EnergyCommission and theUniversity of California

• Established in March 2002

• http://cwec.ucdavis.edu/

• [email protected]


Why Wind Energy?Why Wind Energy?• Renewable

– Guaranteed “fuel” availability– Large available resource in USA– No cost volatility– Does not rely on water

• Clean– Emission free operation– No waste generation

• Installation– Rapidly deployed

• Security– Non-centralized installation and operation– No imported fuel requirement

• Economics– Cost effective energy– Local economic benefits

Source: van Dam

Source: GE

Cost of wind-based electricity, $c/kWh


Simple COE ComparisonSimple COE Comparison• Wind turbine

– 1 MW, $2.0 million, 20 years, Capacity Factor = 0.35

– COE = $32.62/MWh (based on capital cost only)

• Natural gas fired combined-cycle gasturbine CCGT– Natural gas = $4.50/MBtu (or MMBtu)

– Heat rate = 7000 Btu/kWh = 7.0 MBtu/MWh

– COE = $31.50/MWh (based on fuel cost only)


• In the 1980s, USA was theleader in installed wind-based electric powergeneration capacity

• From the 1990s untilrecently, other countriesoutpaced the USA

• Over the last few years,pace of installation in theUSA has increased rapidlyReasons:– Increase/uncertainty in

fossil fuel prices– PTC (Federal)– RPS (States)

Installed WindInstalled WindPower CapacityPower Capacity


Global InstalledGlobal InstalledWind PowerWind PowerCapacityCapacitySource: GWEC


U.S. Installed Wind PowerU.S. Installed Wind PowerCapacityCapacitySource: AWEA


Evolution of U.S. Utility-ScaleEvolution of U.S. Utility-ScaleWind Turbine TechnologyWind Turbine Technology

Year

Rot

or D

iam

eter

(m)

Source: NREL


Standard ArchitectureStandard Architecture

• Represents nearlyall new equipment

• Three blades

• Upwind rotor

• Active yaw

• Freestandingtower


VestasVestas3.0 MW3.0 MW90 m90 m


Technical Specifications - Technical Specifications - VestasVestasV90V90

• Rotor– Diameter 90 m– Swept area 6,362 m2

– Nominal rpm 16.1→Tip speed= π⋅D⋅rpm/60 = 75.9 m/s– Operational range 8.6 - 18.4 rpm– Number of blades 3– Power regulation Pitch/OptiSpeed

(Note, OptiSpeed not available in USA and Canada)

– Brake Independent blade pitch(Three separate hydraulic pitch systems)

• Tower– Hub height 80 m, 105 m


Technical Specifications - Technical Specifications - VestasVestasV90V90• Operational data

– Cut-in wind speed 4 m/s– Nominal wind speed 15 m/s– Cut-out wind speed 25 m/s

• Generator– Type Asynchronous with OptiSpeed– Rated output 3,000 kW– Operational data 50 Hz, 1000 V

• Gearbox– Type Two planetary and one helical stage

• Weight– Nacelle 70 t– Rotor 41 t– Tower

• 80 m, IEC IA 160 t• 105 m, IEC IIA 285 t


Region 4

• Region 1Turbine is stopped orstarting up

• Region 2Efficiency maximizedby maintainingoptimum rotor RPM(for variable speedturbine)

• Region 3Power limited throughblade pitch

• Region 4Turbine is stoppeddue to high winds(loads)

Turbine Power CharacteristicsTurbine Power CharacteristicsSource: Johnson et al (2005)Source: Johnson et al (2005)


• Solidity = Blade Area / Ad

• TSR = Tip Speed / Vw

• High power efficiency forrotors with low solidity andhigh TSR

• Darrieus (VAWT) is lessefficient than HAWT

Efficiency of Various Rotor DesignsEfficiency of Various Rotor DesignsButterfield (2008)Butterfield (2008)

Cp

Tip Speed Ratio TSR = π D RPM / (60 Vw)


Challenges: Challenges: OldOld and New and New• Environmental Impacts

– Birds and bats• “Reliance on fossil fuels hurts birds, plain and simple. Pollution, destruction of habitat from mining,

and potentially disastrous global climate change are all significant stresses on birds and other wildlife.Wind power, when sited properly after adequate study, is a better option. Modern wind projectsundergo a significant amount of review and study for a variety of factors before construction begins.”David, J. Miller, Executive Director, Audubon New York, 2006(http://ny.audubon.org/news/060711.htm)

– Visual• Windplant aesthetics have improved significantly since the 1980s

– Noise• Newer turbines are significantly quieter, driven by zoning ordinances and strict European noise

standards

• Cost– Cost of electricity from wind compares favorably to wholesale power prices

• Reliability– Improved engineering and design through accumulated years of experience

and international design standards have resulted in increased reliability butproblem areas remain


Challenges: Old and Challenges: Old and NewNew• Variability / Integration

– Increasing penetration of variable power sources such as wind has resulted in grid impact concerns– It is not necessary, economical, or desirable to manage the variability of each wind turbine or each wind

plant… manage the entire system, instead.– Load is the dominant component of the system.– Successfully integrating high penetrations isn’t trivial, but it is economically feasible

• Electric power transmission constraints– Transmission constraints are an issue for renewable and other electric power sources

• Size– Large size of turbines leads to challenges:

• Manufacturing• Transport• Construction cranes• Setbacks• Aviation safety

• Costs are up– Weak dollar, supply chain shortages

• Education– Rapid growth is creating demand for qualified personnel at all levels

• Financial crisis– Projects are halted because of difficulty accessing credit– Large financial losses diminish value of PTC


Challenges to Meet Goal of 20%Challenges to Meet Goal of 20%Wind by 2030Wind by 2030• Massive growth in installed

capacity– 25 GW at start of 2009– > 300 GW by 2030

• Widely distributed across the USA– High wind sites– Moderate wind sites– Offshore

• Performance is critical– Capital cost– Capacity factor– O&M cost

• Human capital for manufacturing,logistics, installation, O&M

Source: NREL


Critical Performance ChallengesCritical Performance Challenges• Reduction in capital cost

– Recently, turbine cost haveincreased sharply

• Increase in turbine capacityfactor– Larger rotors for given

rated power

• Reduced O&M cost– Rapid growth has resulted

in reliability issues

• Foster confidence inindustry

Source: NREL


Reduced Capital CostReduced Capital Cost• Learning Curve Effect

– Measures cost reduction foreach doubling of capacity

– Historically learning curve effecthas been small for windturbines because of rapidchanges in technology and size

• Opportunities– Maturing of industry is leading

to less frequent productchanges

• GE, shipped 10,000th 1.5MW turbine in November2008

– Weight reduction• Less material• Advanced materials

– More automation– Design for manufacturability


Increased Capacity FactorIncreased Capacity Factor• Larger rotors

– Increased energycapture

– Longer, lighter blades– Load alleviation

(passive, active)

• Taller towers– Higher wind speeds– Innovative towers,

erection methods

• Reduced losses– Improved drivetrains,

power electronics– Wake losses


Advanced Advanced Drivetrain Drivetrain R&DR&D

Enron/GE 1.5 MW Clipper Multi-Generator

NPS Direct Drive-Permanent Magnet

Zond Z-750 Integrated

GEC Medium Speed Source: McNiff, 2007


Increased ReliabilityIncreased ReliabilitySource: Veers, 2007Source: Veers, 2007

Gea

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Wind Stats: 2003-05 Stop Hours per Turbine Subsystem

• Impact- Reduced O&M- Increased energy capture- Increased availability- Increased confidence in technology- Reduced financing and insurance cost


Offshore Wind Energy DevelopmentOffshore Wind Energy DevelopmentMiddelgrunden, Copenhagen, Denmark, 1st Offshore Windplant, 20 x Siemens 2.0 MW

Depth of 20 m is about limit for off-shore wind turbines with monopile foundations

Source: van Dam


C.P. van Dam

Source: NREL

U.S. Deep Water Coastal WindU.S. Deep Water Coastal WindResourceResource


Source: NREL


Airborne Wind PowerAirborne Wind Power


Airborne Wind Power GenerationAirborne Wind Power Generation• Higher and more constant winds at higher

altitudes. Power densities as high as 20 kW/sqmcompared to < 0.8 kW/sqm for terrestrial systems

• Major hurdles facing airborne wind powergeneration are:– Cost competitiveness of land-based wind power and

other renewables (e.g., MHK: 8 kW/sqm)– Lack of airborne wind power demonstration systems– Lack of cost of energy model for airborne wind energy


Departing ThoughtsDeparting Thoughts

• Wind power is:– Clean, renewable, emission-free– A mature and reliable technology– Economically viable

• Wind power can and will continue to play asignificant role in the global energy portfolio atutility-, community- and building-scales

• Growth has brought new issues, but also newopportunities

• Lack of transmission and concerns about windintegration are most pressing issues that arebeing addressed

• RD&D is being conducted to further improvewind turbine and blade technology and reducewind COE Shiu

wind energy: status, challenges, opportunities · mission statement: support the development of...

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