Arlington, in 1978, 1980, and 1985, respectively, all in Electrical Engineering. In 1985, he joined the University of Texas at Arlington, where he is currently a professor of Electrical Engineering and director of the Energy Systems Research Center. Prof. Lee has been involved in the revision of IEEE Std. 141, 339, 551, and 739. He is the Secretary of the IEEE/IAS, Industrial & Commercial Power Systems Department (ICPSD), the Committee Chairman of the Energy Systems Committee at ICPSD, and the associate editor of IEEE/IAS. Currently, he is the project manager of the IEEE/NFPA collaboration on Arc Flash Phenomena Research Project. Prof. Lee has been involved in research on renewable energy, power flow, transient and dynamic stability, voltage stability, short circuits, relay coordination, power quality analysis, demand response, utility deregulation, and on-line equipment protection, monitoring and control systems. He has served as the primary investigator (PI) or Co-PI of more than 70 funded research projects He has published more than 160 journal papers conference proceedings. He has provided on- site training courses for power engineers in Panama, China, Taiwan, Korea, Saudi Arabia, Thailand, and Singapore. He has refereed numerous technical papers for the IEEE, the IEE and other professional organizations.
Transcript
Wei-Jen Lee (S’85-M’85-SM’97-F’07) received the B.S. and M.S. degrees from National Taiwan University, Taipei, Taiwan, R.O.C., and the Ph.D. degree from the University of Texas, Arlington, in 1978, 1980, and 1985, respectively, all in Electrical Engineering. In 1985, he joined the University of Texas at Arlington, where he is currently a professor of Electrical Engineering and director of the Energy Systems Research Center.
Prof. Lee has been involved in the revision of IEEE Std. 141, 339, 551, and 739. He is the Secretary of the IEEE/IAS, Industrial & Commercial Power Systems Department (ICPSD), the Committee Chairman of the Energy Systems Committee at ICPSD, and the associate editor of IEEE/IAS. Currently, he is the project manager of the IEEE/NFPA collaboration on Arc Flash Phenomena Research Project.
Prof. Lee has been involved in research on renewable energy, power flow, transient and dynamic stability, voltage stability, short circuits, relay coordination, power quality analysis, demand response, utility deregulation, and on-line equipment protection, monitoring and control systems. He has served as the primary investigator (PI) or Co-PI of more than 70 funded research projects He has published more than 160 journal papers conference proceedings. He has provided on-site training courses for power engineers in Panama, China, Taiwan, Korea, Saudi Arabia, Thailand, and Singapore. He has refereed numerous technical papers for the IEEE, the IEE and other professional organizations.
Prof. Lee is a Fellow of IEEE and a registered Professional Engineer in the State of Texas.
Wind Generation: A Wind Generation: A Prominent Form of Prominent Form of Renewable EnergyRenewable Energy
Wei-Jen Lee, Ph.D., PEWei-Jen Lee, Ph.D., PEDirector and ProfessorDirector and Professor
Energy Systems Research Energy Systems Research CenterCenter
The University of Texas at The University of Texas at ArlingtonArlington
February 4, 2009February 4, 2009
Humanity’s Top Ten Humanity’s Top Ten Problems for next 50 Problems for next 50
yearsyears1. Energy
2. Water
3. Food
4. Environment
5. Poverty
6. Terrorism & War
7. Disease
8. Education
9. Democracy
10.Population
2003: 6.3 Billion people
2050: 9-10 Billion peopleSource: Nobel laureate, Richard Smalley
IntroductionIntroduction
Though the oil price has dropped recently, Though the oil price has dropped recently, the concerns on limited resources of fossil the concerns on limited resources of fossil fuel and global warming remain the same. fuel and global warming remain the same. Renewable energy is a hot issue in today Renewable energy is a hot issue in today competitive market. competitive market.
Solar, wind and hydrogen are among Solar, wind and hydrogen are among blistering subjects in the last few decades. blistering subjects in the last few decades.
Wind powered generation is one of the most Wind powered generation is one of the most mature and cost effective resources among mature and cost effective resources among different renewable energy technologies. different renewable energy technologies.
World wind energy capacity has expanded World wind energy capacity has expanded at an annual rate of 25% since the 1990s. at an annual rate of 25% since the 1990s.
People Want Renewable People Want Renewable Energy!Energy!
Total Installed Wind CapacityTotal Installed Wind Capacity
Wind MapWind Map
US 1999 Installed Wind US 1999 Installed Wind Power Capacity (MW)Power Capacity (MW)
US 2008 Installed Wind US 2008 Installed Wind Power Capacity (MW)Power Capacity (MW)
TOTAL INSTALLED U.S. WIND ENERGY CAPACITY: 13,885 MW as of October 15, 2008 Source: AWEA
Top 10 Installed Wind Power Top 10 Installed Wind Power Capacities (2007)Capacities (2007)
1 2 3 4 5
State Existing Under Construction Rank (Existing)
Texas 5,316.65 1,997.10 1
California 2,483.83 290.00 2
Minnesota 1,299.75 46.40 3
Iowa 1,294.78 549.10 4
Washington 1,195.38 94.00 5
Colorado 1,066.75 0.00 6
Oregon 887.79 201.60 7
Illinois 735.66 171.00 8
Oklahoma 689.00 0.00 9
New Mexico 495.98 0.00 10
Largest Wind Farms in U.S.
1 2 3 4 5
Largest Wind Farms in U.S. (all U.S. wind farms >= 200 MW) as of end of August 10, 2007
Project Name State Capacity Year Online Owner
Horse Hollow TX 736 2005/2006 FPL Energy
Sweetwater TX 5052003, 2005, 2007
Babcock & Brown, Catamount
Buffalo Gap TX 353 2005, 2007 AES
Maple Ridge NY 322 2005/2006 PPM Energy/Horizon
Stateline OR/WA 300 2001/2002 FPL Energy
King Mountain TX 281 2001, 2003 FPL Energy
Wild Horse WA 229 2006 Puget Sound Energy
New Mexico Wind Energy Center NM 204 2003 FPL Energy
Big Horn WA 200 2006 PPM Energy
US 2030 Estimated Installed US 2030 Estimated Installed Wind Power CapacityWind Power Capacity
Wind Energy in TexasWind Energy in Texas Texas “Renewable Portfolio Standard” Texas “Renewable Portfolio Standard”
mandating 2,000 MW of electricity mandating 2,000 MW of electricity generation from renewable resources by generation from renewable resources by 2009 (Senate Bill 7, 1999).2009 (Senate Bill 7, 1999).
If fully explored, wind power could If fully explored, wind power could provide enough power for the whole provide enough power for the whole statestate..
Wind Energy in Texas Wind Energy in Texas
In July 2006, Texas exceeded California and In July 2006, Texas exceeded California and became Number One in the US in terms of became Number One in the US in terms of wind generation installation. wind generation installation.
To promote renewable energy, ERCOT has To promote renewable energy, ERCOT has identified 25 preliminary areas of interest for identified 25 preliminary areas of interest for Competitive Renewable Energy Zone (CREZ) Competitive Renewable Energy Zone (CREZ) and proposed infrastructure improvement and proposed infrastructure improvement plans to support power delivery from those plans to support power delivery from those areas to the load centers. areas to the load centers.
This development will have significant impact This development will have significant impact on the reduction of the green house gas on the reduction of the green house gas (GHS) emissions. Presently, the total installed (GHS) emissions. Presently, the total installed wind generation in Texas exceeds 6,000MW wind generation in Texas exceeds 6,000MW with more than 20,000MW in the with more than 20,000MW in the interconnection queue. interconnection queue.
Wind Energy in TexasWind Energy in Texas CREZ MAPCREZ MAP
Wind Generation Unit SizeWind Generation Unit Size
Wind Power EconomicsWind Power Economics
Can youCan yousee the man?see the man?
Source: Dr. James Liao, WFEC
BBEELLEEIIVVEE
IITT
OORR
NNOOTT!!
Source: Dr. James Liao, WFEC
The power in the wind is
proportional to
The cube of wind speed
(proportional to installation
height) Size of the rotor (swept area) The air density
(affected by temperature and
altitude)
Note : The standard air density is
1.2256 kg/m3
Power in the WindPower in the Wind
32
2
1
2
1AvvAvvPwind
v
A
Usable Wind PowerUsable Wind Power
Wind turbine is designed to produce Wind turbine is designed to produce maximum output at a certain wind speed, maximum output at a certain wind speed, normally around 33 mph [15 m/s].normally around 33 mph [15 m/s].
Betz’s law : 59% maximum limitation of the Betz’s law : 59% maximum limitation of the energy can be extracted from the wind.energy can be extracted from the wind.
Real operation : Turbine mechanics, blade Real operation : Turbine mechanics, blade design, type of rotor, friction loss, etc. affect design, type of rotor, friction loss, etc. affect the performance of the generation output.the performance of the generation output.
3
2
1AvC
vPCvP
p
windpturbine
Cp is called Power Coefficient
Power Curve (Theoretical)Power Curve (Theoretical)
5 10 15 20 25 30 35 40 45 50 550
200
400
600
800
1000
1200
1400
1600
1800
2000Power & Power coefficient curve for NM72 IEC I
Po
we
r [k
W]
5 10 15 20 25 30 35 40 45 50 550
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Wind speed [mph]
Cp
Cut-in
PowerRated
Cut-out
Power Coefficient
Power Curve (Actual)Power Curve (Actual)
Direct transformation Direct transformation (Turbine power curve) (Turbine power curve) cannot provide good cannot provide good forecast accuracy due forecast accuracy due toto Wind speed varies at Wind speed varies at
different heights. different heights. Flow of wind is not Flow of wind is not
horizontally uniform.horizontally uniform. Wind speed varies at Wind speed varies at
different locations. different locations.
Wind Speed EstimationWind Speed Estimation
The roughness of the surface will affect the The roughness of the surface will affect the wind speed at different heights.wind speed at different heights.
General speaking, we can use the following General speaking, we can use the following equation to estimate the wind speed at the equation to estimate the wind speed at the height of wind turbine:height of wind turbine:
wherewhereV(z): Wind Speed at Height zV(z): Wind Speed at Height z
V(zV(zrr): Actual Wind Speed at Height z): Actual Wind Speed at Height zrr
zz00: The Roughness of the Surface: The Roughness of the Surface
00
ln/lnz
z
z
zzVzV rr
Source: J.F. Manwell, J.G. McGowan, and A.L.Rogers, “Wind energy explained,” John Wiley & Sons, 2002
Roughness Length of Roughness Length of LandscapeLandscape
Landscape Type Roughness length (mm)
Very smooth, ice or mud 0.01
Calm open sea 0.20
Blown sea 0.50
Snow surface 3.00
Lawn grass 8.00
Rough pasture 10.00
Fallow field 30.00
Crops 50.00
Few trees 100.00
Many trees, hedges, few buildings 250.00
Forest and woodlands 500.00
Suburbs 1500.00
Centers of cities with tall buildings 3000.00
AvailabilityAvailability – a measure of the time a – a measure of the time a generating unit is capable of providing generating unit is capable of providing service. (operation hours/clock hours)service. (operation hours/clock hours)
Capacity factorCapacity factor – the ratio of the total – the ratio of the total energy generated for a specified period energy generated for a specified period to the maximum total energy that to the maximum total energy that could have been generated if operated could have been generated if operated at maximum capacity for the same at maximum capacity for the same period (It is required at least 28% to be period (It is required at least 28% to be economics)economics)
Wind Power ProsWind Power Pros PlentifulPlentiful Clean energy, no thermal dischargeClean energy, no thermal discharge Technology is well-developed, fast erectionTechnology is well-developed, fast erection Cost competitive, as low as 3 to 5 cents/kWhCost competitive, as low as 3 to 5 cents/kWh Support economy, create jobsSupport economy, create jobs Federal and state tax credit (Incentive for Federal and state tax credit (Incentive for
the investors)the investors)
Wind Power ConsWind Power Cons Variation in power productionVariation in power production Require infrastructure upgrade for power Require infrastructure upgrade for power
deliverydelivery Produce relatively small power outputsProduce relatively small power outputs Reactive compensation for induction Reactive compensation for induction
generatorgenerator Capital investmentCapital investment
Wind Power’s Natural Wind Power’s Natural Characteristics and Related Characteristics and Related
ResearchesResearches RemoteRemote: Wind resources is often distant from load sites.: Wind resources is often distant from load sites. VariableVariable: Plant output varies with variations of the : Plant output varies with variations of the
wind.wind. NewNew: Operators are more comfortable with established : Operators are more comfortable with established
power technologies.power technologies.
0
200
400
600
800
1000
1200
1400
1600
1800Power (KWatt)
0 Day 1 Day 2 Day 3
Non Coincident PeakNon Coincident Peak
Wind Generation in TexasWind Generation in Texas
Source: ERCOT
Unit Commitment Unit Commitment SchedulingScheduling
Market clearing price for energy and total Market clearing price for energy and total wind generation on February 22, 2005 wind generation on February 22, 2005
0
200
400
600
0 5 10 15 20-100
0
100
200
Price (All zones) ($)
Price (All zones)Wind Generation
Hour
Win
d G
enera
tion (
MW
)
Price DipsPrice Dips Market clearing price for energy (MCPE) and Market clearing price for energy (MCPE) and
total wind generation on April 27, 2007.total wind generation on April 27, 2007.
Committing unneeded generationCommitting unneeded generation Scheduling unneeded generationScheduling unneeded generation Allocating extra load-following Allocating extra load-following
capabilitycapability Violation of system performance Violation of system performance
criteria (For example, spinning criteria (For example, spinning reserve)reserve)
Requirement of reactive power Requirement of reactive power supply for induction-type generatorsupply for induction-type generator
These will increase the Ancillary These will increase the Ancillary Service CostsService Costs
Voltage FluctuationVoltage Fluctuation
BusesBuses % Real Power deliver by wind Generator% Real Power deliver by wind Generator
100%100% 75%75% 50%50% 25%25%
IG operate at 0.85 leading PF, Fix Qc=70.5 MVAR IG operate at 0.85 leading PF, Fix Qc=70.5 MVAR (Unity PF at 100% of real power)(Unity PF at 100% of real power)
Voltage Ride-Through Voltage Ride-Through CapabilityCapability
Possible threat when fixed capacitor is Possible threat when fixed capacitor is installed at the terminal of induction installed at the terminal of induction generator for power factor correction. generator for power factor correction. (0.95 leading power factor at rated (0.95 leading power factor at rated output)output)
10 minute ahead forecasting
Harvest Wind CapacityHarvest Wind Capacity
Wind Generation is Uncertain,Wind Generation is Uncertain, Forecast error distribution can Forecast error distribution can be used for wind generation dependable capacity analysisbe used for wind generation dependable capacity analysis
0 10 20 30 40 50 60 70 80 90 1000
10
20
30
40
50
60
70
80
Hour
Pow
er O
utpu
t [M
W]
Actual Wind GenerationEstimated Wind Generation
Forecasted Dependable Wind Forecasted Dependable Wind Capacity for Unit Capacity for Unit
