EE483 02 Slides Power and Energy V3.ppt
Transcript of EE483 02 Slides Power and Energy V3.ppt
1/21/2010
1
Renewable Energy Sources
Class Slides
Energy and Power
Group 2
Prepared by
Luis G. Pérez
School of
Electrical Engineering and
Computer Science
Important Preliminary Note
The material presented here is not to be used for profit purposes. The document is for the
sole use in the undergraduate class “Renewable Energy” at the School of Electrical
Engineering and Computer Science of Washington State University. This course is being
partially sponsored by Puget Sound Energy, Inc.
The material was prepared using, among other sources, figures and data tables which can be
found in public sites in the INTERNET. However, the slides –as a set– are not public
documents, they are intended for the exclusive use of the students registered in this class.
Some of the slides were originally created by the instructor, and some have been copyrighted
by Schweitzer Engineering Laboratories, Inc. Those slides are used here with permission. In
general, the document should not be copied, reproduced or used for any purpose without
citing the original sources.
It is strongly recommended that the students consult the original sources of the figures and
schemes using INTERNET search engines and the list of references shown at the end of this
document.
Luis G. Pérez
Instructor
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Objectives
• Outline electrical energy consumption in different
regions of the world
• Describe and use load curves (demand curves)
• Describe and use load duration curves (LDC)
• Recognize “traditional” fossil-fueled power plants
• Describe main characteristics of renewable power
plants• Hydroelectric (dam, river and tidal)
• Wind farms
• Solar thermal and solar photovoltaic
• Geothermal
• Discuss the main advantages and disadvantages of
traditional and renewable power plants
• Define generation reliability
World Regions:
Electrical Energy Consumption
4,543.15
758.95
3,242.98
1,143.46
518.73 478.44
5,072.60
15,758.31
0.00
2,000.00
4,000.00
6,000.00
8,000.00
10,000.00
12,000.00
14,000.00
16,000.00
TW
h
North
Am
erica
Cent. &
Sth
Am
erica
Euro
pe
Eura
sia
Mid
dle
East
Afric
a
Asia
&
Oceania
World T
ota
l
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U. S. Average electrical Power Per Capita
(2005)
Average power per capita (2005)
297
1,460
0
200400
600
800
10001200
1400
1600
World US
Wa
tts
/in
ha
bit
an
t
Symbols for One-Line Diagrams of
Electrical Power Systems
Generator
Transformer
Switch (Isolator)
Circuit Breaker
Power Line
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Power System One-Line Diagram
Generation
12 kV or
18 kV, etc.
TransmissionDistribution
12 kV or
15 kV, etc.
Transmission
Line
Generators
Step-Up
TransformerStep-Down
Transformers
Substation Substation
115 kV or 345 kV or 765 kV, etc.
Generation needs are determined by the demand
Load Curve
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
0.00 5.00 10.00 15.00 20.00 25.00
Time (hours)
Load
(M
W)
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Load Curve (Demand Curve)
0T t (hours)
Ppeak
P (MW)
U
Example of day curve (T=24 hours)
Peak demand = Ppeak
∫ ⋅=T
dtPU0
100
100
⋅⋅
=
⋅=
peak
peak
ave
PT
ULF
P
PLF
T
UdtP
TP
T
ave =⋅= ∫01
Energy:
Average demand:
Load factor:
Pave
[MWh]
Load Factor
0T
P (MW)
0T
P (MW)
Curve 1. Load curve with low LF
Curve 2. Load curve with a LF close to 1.0
Pave
Pave
Although the energy required in
both cases is similar (area under
the curve), the high peaks of
curve 1 impose a major
requirement. Generation has to be
set to cover the maximum (peak)
load.
How do we improve the LF?
time
time
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Load Duration Curve
P
AB
C
D
F
G
H
J
I
Load Curve
P
A
DF
G
J
I
Load Duration Curve (LDC)HC
B
time
time
Example: Load Curve for a Certain Region
Load Curve
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
0.00 5.00 10.00 15.00 20.00 25.00
Time (hours)
Load
(M
W)
Pave≈13,300 MW
Ppeak ≈17,000 MW
U=319,200 MWh
LF=78.23 %
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Example Duration Curve (1 day)
Load Duration Curve (LDC)
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
0.00 5.00 10.00 15.00 20.00
Time (hours)
Lo
ad
(M
W)
Unit Commitment
- In a system with different power plant types and sizes, how do we
assign the generation units in order to cover the demand?
- Consider reserve
- Unit commitment by plant size, cost-efficiency, reliability
- Optimum power flow considers the effect of the transmission network
0T
P (MW)
0T
P (MW)
Base Base
Peak
Peak
Reserve
Intermediate Intermediate
LDCLC
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Example Duration Curve (1 day)
Base Power and Average Power
Load Duration Curve (LDC)
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
0.00 5.00 10.00 15.00 20.00
Time (hours)
Lo
ad
(M
W)
Pave≈13,300 MW
Pbase=10,000 MW
Ppeak ≈17,000 MW
Power Production Methods
(Utility-Scale Size)
Hydroelectric Plants
Thermal Plants
Solar Plants
Wind Plants
• High Head
• Medium Head
• Low Head
• Gas Turbines
• Coal - Steam Turbines
• Combined Cycle Plants
• Nuclear – Steam Turbines
• Diesel
• Geothermal – Steam Turbines
• Photovoltaic
• Thermal (steam turbine)
• Several types
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Electric Power Generation Plants
Fuel - First Stage Second Stage Third Stage Fourth Stage
Main Conversion
Devices
Wind (G, R) Mechanical Electrical Wind turbines
Water-River (G, R) Mechanical Electrical Hydroturbines
Gas (FF) Thermal Mechanical Electrical Gas turbines
Gasoil (FF) Thermal Mechanical Electrical Diesel engine
Coal (FF) Thermal (Steam) Mechanical Electrical Steam turbines
Biomass (G, R) Thermal (Steam) Mechanical Electrical Steam turbines
Gas (FF) Thermal (Steam) Mechanical Electrical Steam turbines
Uranium [Nuclear] (G?,R?) Thermal (Steam) Mechanical Electrical Steam turbines
Solar (G,R) Thermal (Steam) Mechanical Electrical Solar heaters
Solar (G, R) Electrical Solar photovoltaic cells
Hydrogen (G, R) Electrical Fuel Cells
Chemical Elements (G?, R?) Electrical Batteries
Generation of Electrical Energy
Note:
This is how most experts consider these energy sources. There is not absolute consensus on this matter,.
G = Green; R= Renewable; FF = fossil fuel
Diesel Generation Plants
Generator
DieselEngine
Biodiesel? Alcohol? Biofuel? Transportation sector
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Basic Diagram of a Steam Generation Unit
Steam Turbine
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Also a Steam Machine
--James Watt (1736-1819)
Basic Diagram of a Coal Plant (Steam TG)
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Basic Diagram of a Nuclear Plant
Basic Diagram of a Gas Generation Unit
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Basic Diagram of a Combined Cycle Generation Compound
Basic Diagram of a Hydroelectric Generation Unit
RESERVOIR
AFTERBAY
Generator
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Hydroturbine and Generator Rotor
Also an Old Idea
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Power Formulas - Head
Pwt = ρwt·Q · g · h
Pel = η ·Pwt
h < 10 m 10 < h < 100 m h > 100 m
ρwt= 1000 kg/m3
Q= water flow rate in m3/s
g= 9.8 m/s2 (accel. of gravity)
h = effective height in m
Efficiency
η < 0.85
Three Types of Hydro Turbines
Pelton Kaplan Francis
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100
101
102
103
100
101
102
103
HE
AD
(m
)
FLOW (m3/s)
0.1 MW
0.1 MW
10 MW
100 MW
1000 MW
Plot of the Power Formula (Efficiency not Included)
100
101
102
103
100
101
102
103
HE
AD
(m
)
FLOW (m3/s)
0.1 MW
0.1 MW
10 MW
100 MW
1000 MW
Approximate application Range of Water Turbines
Pelton
Francis
Kaplan
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Nuclear, hydro, coal, combined-cycle powerful facts:
Installed capacity of a traditional plant may be very large
and the storage capacity is enormous
• A single turbine-generation unit of a coal-fired thermal
plant may reach near 1000 MW
• Typical plant capacities (steam, combined cycle) are
500 – 5,000 MW
• Largest hydroelectric plants in the world:
-Three-Gorges (China): 22,500 MW (final)
-Itaipu (Brazil): 12,000 MW
-Guri (Venezuela): 10,000 MW
-Grand Coulee (U. S. A.): 7000 MW
Basic Diagram of a Wind Generation Unit
Pwind=(1/2) · ρ · A · v3
Pelec=Cp · η · Pwind
A= turbine area in m2
V= wind speed in m/s
Cp = Betz’s coefficient≈ 0.4
η=0.85 …0.95
Air density: ρ=1.2256 kg/m3
Type of generator used:
-Synchronous (PM or traditional)
-Induction (asynchronous)
-D.C. (small units)
In all cases the generator needs
power electronic controllers.
Utility Scale Range: 1.5 .. 3.6 MW
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Talking about old ideas
Power vs Wind Speed Curve
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Wind power in the World
Wind Farms Examples
Terminology
-Capacity factor
-Capacity credit
-Wind penetration
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One-line diagram of Conventional Plants
(Thermal or Hydroelectric)
200 MW 200 MW 200 MW 200 MW
Generators
Step-Up
Transformers
Transmission
Substation
To HV Transmission System
(230 kV,345 kV, 500 kV, etc.)
Example One-line Diagram of a Wind Plant
(“Wind Farm”)WTG
Example:
2 MW
35 kV
Collector Buses
Sub-
Transmission
Substation
To other WTG
115 kV
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Wind: Advantages and Disadvantages
Disadvantages
• Operation problems (frequency and
voltage incursions, dynamic
response), harmonics
• Noise, landscape aesthetics, bird
collision
Advantages
• Practically endless fuel source
(wind)
• Costless fuel
• No pollution into the air (green,
“environmentally friendly”): no
CO2 emissions, no heat to the
atmosphere
• Minimum paperwork on
permissions
• Relative expedite construction
Other issues
1. Many generators and large areas are
needed to reach high capacity
2. Transmission infrastructure needed
3. Intermittency
4. Even worse, no-coincidence (sorage)
5. Energy in excess and storage issues
6. Low capacity factor
7. The figure of “capacity credit” is
used
A Powerful Reason
Marginal emissions in New England for the year 2002(*)
1 GWh of wind power will avoid the following amounts
(*) Source: ISO New England Inc.
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Existing solar thermal plant
Basic Diagram of a Solar Generation Plant
(Solar-thermal)
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Basic Diagram of a Solar Generation Plant
(Photo Voltaic)
Photo-Voltaic Power. Some Figures.
P= η·E ·A
A= effective cell area in m2
E = Irradiance in W/m2
η = Efficiency ≈15 .. 30% at nominal
conditions
Calculate the area needed to generate power
for 100 homes at 10 kW per home.
Suppose E = 1000 W/m2 (perfect clear
day); and η=0.2
A = P/(η·E )=100x10,000/(0.2·1000 ) =
=5,000 m2 ≈1.24 acres
Notes:
1. Obtain more voltage and current by
arranging PV cells series-parallel
2. The largest solar PV plant has a
maximum capacity of 11 MW
Max. power
Small fuel cell I-V curve
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A solar (PV) plant
Solar Power Plants:
Advantages and disadvantages
Disadvantages
• Generates in d. c. (disadvantage?)
• Need power electronics �
harmonics
• Landscape aesthetics
Advantages
• Practically endless fuel source
(sun)
• Costless fuel
• No pollution into the air (green,
“environmentally friendly”): no
CO2 emissions, no heat to the
atmosphere
• Minimum paperwork on
permissions
• Relative expedite construction
Other issues
1. Extremely large areas are needed to
reach high capacity
2. May need transmission
infrastructure
3. Intermittency
4. No-coincidence and storage issues
5. Low capacity factor
6. The figure of “capacity credit” is
used
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Small-Scale PV Solar
Power
Charger/
Rectifier
DC/AC
Inverter
BatteriesDC
Loads
AC
Loads
Sunlight
PV Panels
Solar Power - Thermal:
Parabolic Concentrator with Thermal Engine
Power ~ 3 kW per unit)
Source:
http://www.infiniacorp.com/
Thermal
engine
Parabolic
Mirror
Heat concentrator
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Basic Diagram of a Tidal Plant
(a particular type of hydro plant)
Serious Power:
Pwt=(1/2) · ρwt · A · v3La Rance – France
1966 - (240 MW)
Geothermal Plants
-This is non-conventional but might be considered non-renewable
-There are many in the USA (43 in California with total 1.8 GW installed)
-Geyser � direct
-Water injection
Geysers Valley
Power Plant
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Geothermal Plants
Geothermal Plant Schematic
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Summary
Wind turbine generation systems
Solar thermal and photovoltaic energy
Fuel cellsGeothermal energy Tidal energy
Hydroelectric power
Sources
1. U. S. Department of Energy. Energy Information Administration (EIA). Official Statistics from the
U. S. Government. WEB: http://www.eia.doe.gov/
2. “Renewable Energy: A power for a Sustainable Future,” 2nd edition, G. Boyle, Oxford University
Press, 2004, ISBN 0-19-926178-4.
3. http://www.power-technology.com/projects/san_joaquin/images/Combined3.jpg
4. http://www.powergeneration.siemens.com
5. http://www.gasturbine.pwp.blueyonder.co.uk/CT3201-schema.jpg
6. http://www.amrclearinghouse.org/Sub/landreclamation/cfb/diagram-hires.gif
7. http://blogs.orlandosentinel.com/community_conway_blog/files/Nuclear_Plant.gif
8. http://www2.cemr.wvu.edu/~smirnov/mae320/figs/F8-1.jpg
9. http://homebrewpower.blogspot.com/2008_01_01_archive.html
10. http://henk.elfwood.com/windmill.jpg.html
11. http://www.powerhousetv.com/stellent2/groups/public/documents/pub/phtv_eb_re_000315-2.jpg
12. http://vicerp.org/files/files/Anlagenschema_englisch.jpg
13. http://www.yourenergygeneration.com/images/energy/solar2.jpg
14. http://www.eas.asu.edu/~holbert/eee463/solar_photovoltaic.gif
15. http://www.infiniacorp.com/
16. http://www.edf.fr/html/en/decouvertes/voyage/usine/retour-usine.html
17. http://geothermal.marin.org/GEOpresentation/sld037.htm
18. http://www.solcomhouse.com/geothermal.htm
19. http://www.energy.ca.gov/geothermal/