Transcript Penetration Level Impact of Wind Powered Generation to

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 Prominent
Form of Renewable Energy
Wei-Jen Lee, Ph.D., PE
Director and Professor
Energy Systems Research Center
The University of Texas at Arlington
February 4, 2009
Humanity’s Top Ten
Problems for next 50 years
1. Energy
2. Water
3. Food
4. Environment
5. Poverty
6. Terrorism & War
7. Disease
8. Education
9. Democracy
2003: 6.3 Billion people
10. Population
2050: 9-10 Billion people
Source: Nobel laureate, Richard Smalley
Introduction




Though the oil price has dropped recently, the concerns
on limited resources of fossil fuel and global warming
remain the same. Renewable energy is a hot issue in
today competitive market.
Solar, wind and hydrogen are among blistering subjects
in the last few decades.
Wind powered generation is one of the most mature
and cost effective resources among different renewable
energy technologies.
World wind energy capacity has expanded at an annual
rate of 25% since the 1990s.
People Want Renewable Energy!
Total Installed Wind Capacity
95000
90000
Capacity (MW)
85000
80000
75000
70000
65000
1. Germany: 22247 MW
2. United States: 16971 MW
3. Spain: 15145 MW
4. India: 7844 MW
5. China: 5906 MW
60000
55000
50000
45000
40000
35000
30000
25000
20000
15000
World total April 2008: 93,881 MW
United States
Europe
Rest of World
08
20
07
06
20
20
05
04
20
20
03
02
20
20
01
00
20
20
99
98
19
97
19
96
19
95
19
94
19
93
19
92
19
91
19
90
19
89
19
88
19
87
Source: Windpower Monthly
19
86
19
85
19
84
19
83
19
19
19
82
10000
5000
0
Wind Map
US 1999 Installed Wind Power
Capacity (MW)
US 2008 Installed Wind 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
Capacities (2007)
1
2
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
3
4
5
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.
Largest Wind Farms in U.S. (all U.S. wind farms >= 200 MW) as of end of August 10, 2007
1
Project Name
State
Capacity
Year Online
Owner
Horse Hollow
TX
736
2005/2006
FPL Energy
Babcock & Brown,
Catamount
Sweetwater
TX
505
2003, 2005,
2007
Buffalo Gap
TX
353
2005, 2007
AES
Maple Ridge
NY
322
2005/2006
PPM Energy/Horizon
Stateline
OR/WA
300
2001/2002
FPL Energy
2
3 Mountain
4
5
King
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 Wind
Power Capacity
Wind Energy in Texas


Texas “Renewable Portfolio Standard” mandating
2,000 MW of electricity generation from renewable
resources by 2009 (Senate Bill 7, 1999).
If fully explored, wind power could provide enough
power for the whole state.
Wind Energy in Texas



In July 2006, Texas exceeded California and became
Number One in the US in terms of wind generation
installation.
To promote renewable energy, ERCOT has identified
25 preliminary areas of interest for Competitive
Renewable Energy Zone (CREZ) and proposed
infrastructure improvement plans to support power
delivery from those areas to the load centers.
This development will have significant impact on the
reduction of the green house gas (GHS) emissions.
Presently, the total installed wind generation in Texas
exceeds 6,000MW with more than 20,000MW in the
interconnection queue.
Wind Energy in Texas

CREZ MAP
Wind turbine basic components
Generator Model
Gear
box
Squirrel cage
induction
generator Capacitor bank
Rotor
Doubly-fed
induction
generator
Gear
box
Rotor
Voltage
source
converter
Voltage
source
converter
Rotor
Direct drive
synchronous
generator
Squirrel-cage
Induction Generator
Doubly-fed
Induction Generator
Synchronous
Generator
Wind Generation Technologies

Wind Generation Unit Size
Wind Power Economics
Can you
see the man?
Source: Dr. James Liao, WFEC
B
E
L
E
I
V
E
I
T
O
R
N
O
T
!
Source: Dr. James Liao, WFEC
Power in the Wind
The power in the wind is proportional to
 The cube of wind speed
v
(proportional to installation height)
 Size of the rotor (swept area)  A
 The air density  
(affected by temperature and altitude)
Note : The standard air density is 1.2256
kg/m3
 

1
1
2
Pwind v   Av  v  Av 3
2
2

Usable Wind Power



Wind turbine is designed to produce maximum output
at a certain wind speed, normally around 33 mph [15
m/s].
Betz’s law : 59% maximum limitation of the energy can
be extracted from the wind.
Real operation : Turbine mechanics, blade design, type
of rotor, friction loss, etc. affect the performance of the
generation output.
Pturbine v   C p  Pwind v 

1
 C p Av3
2

Cp is called Power Coefficient
Power Curve (Theoretical)
Power & Power coefficient curve for NM72 IEC I
2000
1
1800
0.9
1600
0.8
Power
Rated
0.7
1200
0.6
1000
0.5
800
0.4
600
0.3
Power Coefficient
400
200
0
5
Cut-in
0.2
0.1
10
15
20
25
30
35
Wind speed [mph]
40
45
50
0
55
Cp
Power [kW]
1400
Cut-out
Power Curve (Actual)

Direct transformation
(Turbine power curve)
cannot provide good forecast
accuracy due to



Wind speed varies at different
heights.
Flow of wind is not
horizontally uniform.
Wind speed varies at different
locations.
Wind Speed Estimation


The roughness of the surface will affect the wind speed
at different heights.
General speaking, we can use the following equation to
estimate the wind speed at the height of wind turbine:
 z   zr 
V z   V zr   ln  / ln 
 z0   z0 
where
V(z): Wind Speed at Height z
V(zr): Actual Wind Speed at Height zr
z0: The Roughness of the Surface
Source: J.F. Manwell, J.G. McGowan, and A.L.Rogers, “Wind energy explained,”
John Wiley & Sons, 2002
Roughness Length of Landscape
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
Wind Turbine Characteristics

Availability – a measure of the time a
generating unit is capable of providing service.
(operation hours/clock hours)

Capacity factor – the ratio of the total energy
generated for a specified period to the maximum
total energy that could have been generated if
operated at maximum capacity for the same
period (It is required at least 28% to be
economics)
Wind Power Pros






Plentiful
Clean energy, no thermal discharge
Technology is well-developed, fast erection
Cost competitive, as low as 3 to 5 cents/kWh
Support economy, create jobs
Federal and state tax credit (Incentive for the investors)
Wind Power Cons





Variation in power production
Require infrastructure upgrade for power delivery
Produce relatively small power outputs
Reactive compensation for induction generator
Capital investment
Wind Power’s Natural Characteristics
and Related Researches



Remote: Wind resources is often distant from load sites.
Variable: Plant output varies with variations of the wind.
New: Operators are more comfortable with established
power technologies.
Power (KWatt)
1800
1600
1400
1200
1000
800
600
400
200
0
0
Day 1
Day 2
Day 3
Non Coincident Peak

Wind Generation in Texas
Source: ERCOT
Unit Commitment Scheduling
Market clearing price for energy and total wind
generation on February 22, 2005
Price (All zones) ($)
200
600
Price (All zones)
Wind Generation
Wind Generation (MW)

100
400
0
200
-100
0
0
5
10
15
Hour
20
Price Dips

Market clearing price for energy (MCPE) and total wind
generation on April 27, 2007.
US$/MWH
MCPE-April 27, 2007
$200.00
$0.00
-$200.00 1
-$400.00
-$600.00
-$800.00
-$1,000.00
-$1,200.00
6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96
MCPE
MCPE for Every 15 Minutes (0:15 - 24:00)
Variability Increases Operating Costs






Committing unneeded generation
Scheduling unneeded generation
Allocating extra load-following capability
Violation of system performance criteria
(For example, spinning reserve)
Requirement of reactive power supply
for induction-type generator
These will increase the Ancillary Service
Costs
Voltage Fluctuation
Buses
% Real Power deliver by wind Generator
100%
75%
50%
25%
IG operate at 0.85 leading PF, Fix Qc=70.5 MVAR
(Unity PF at 100% of real power)
XX000
1.0219
1.0407
1.0544
1.0651
XX004
0.9944
1.0391
1.0742
1.1043
XX121
1.0177
1.0311
1.0407
1.0480
XX122
1.0278
1.0397
1.0481
1.0543
XX001
1.0228
1.0361
1.0457
1.0529
Case with Qc=90 MVAR, 0.98 pf lagging
XX000
1.0444
1.0620
1.0751
1.0853
XX004
1.0456
1.0883
1.1223
1.1516
XX121
1.0335
1.0460
1.0552
1.0621
XX122
1.0425
1.0536
1.0615
1.0674
XX001
1.0392
1.0518
1.0609
1.0677
Voltage Ride-Through Capability

Possible threat when fixed capacitor is installed at the
terminal of induction generator for power factor
correction. (0.95 leading power factor at rated output)
Harvest Wind Capacity
10 minute ahead forecasting
80
Actual Wind Generation
Estimated Wind Generation
70
Power Output [MW]
60
50
40
30
20
10
0
0
10
20
30
40
50
Hour
60
70
80
90
100
Wind Generation is Uncertain, Forecast error distribution can be
used for wind generation dependable capacity analysis
Forecasted Dependable Wind Capacity
for Unit Commitment Scheduling
80.00
60.00
50.00
40.00
30.00
20.00
10.00
23
21
19
17
15
13
11
9
7
5
3
0.00
1
Wind Power [MW]
70.00
Hour
Forecast
90% confidence
95% confidence
99% confidence
Combining Wind Generation
and Energy Storage
Power
5/28/2006
1.5
1
0.5
0
1
11
21
31
Power w/ Storage
Power w/o Storage
41
51
61
71
81
Time (10 minutes)
91
101
111
121
131
141
Combining Wind Generation
and Energy Storage
Power
1/29/2007
1.5
1
0.5
0
1
3
5
Power w/ Storage
Power w/o Storage
7
9
11
13
Time ( hours )
15
17
19
21
23
On-Line Real Time Health Monitoring
for Wind Generation
Source: www.chinatimes.com
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