To download, head to - http://solarreference.com/cspalliance-csp-thermal-energy-storage-presentation/ Also available at CSP alliance website. Key information includes - direct comparison of a CSP power plant with a conventional power plant, importance of thermal energy storage and the fact that deployment would lead to much more cost reduction than r&d. For colelction of similar resources, head to - http://solarreference.com

1. Concentrating Solar Power Alliance
CSP Overview
SEPA Webinar
Frank (Tex) Wilkins
Executive Director
CSP Alliance
January 31, 2013
CSP Alliance
1
http://www.csp-alliance.org

2. Concentrating Solar Power Alliance
• CSP Alliance - an advocacy group formed in March 2012 whose
goal is to increase the deployment of CSP
• Mission – inform utilities, grid operators, and regulators of the
benefits of CSP with its ability to store thermal energy and provide
dispatchable power
• Members - membership includes Abengoa, BrightSource, Torresol
Energy, Lointek, Cone Drive, and Wilson Solarpower
CSP Alliance
2
http://www.csp-alliance.org

3. Agenda
•
•
•
•
•
•
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Introduction
Plant characteristics
Storage
Solar collection
Projects
Cost and future developments
Question and answer
CSP Alliance
3
http://www.csp-alliance.org

4. CSP Storage & Power Block
CSP Alliance
4
Solana: photos courtesy of Abengoa
.
4
http://www.csp-alliance.org

5. Plant Characteristics
• Project start up – if the turbine is warm it takes 10 minutes from start
to full power. If the plant is operating as spinning reserve, full capacity
can be reached in 4 minutes. The plant can be started and increased
to full load in 10 minutes or less.
• Off-design operation - CSP plants can operate efficiently at off-design
conditions. For example, the efficiency of a steam turbine at 50% load
is about 95% of the design efficiency.
• Power quality – same as power from fossil plants providing reactive
power support, dynamic voltage support, and primary frequency
control.
• Dispatch of stored energy – power can be put onto the grid at any
time, day or night.
CSP Alliance
5
http://www.csp-alliance.org

6. Dispatch Examples
July
800
1.4
700
1.2
600
1.0
500
0.8
400
0.6
300
0.4
200
Solar Resource (W/m2)
900
1.6
Summer: dispatch power to
meet afternoon & early evening
peak demand
January
100
0.0
800
0
0.2
1.6
1.4
700
1.2
600
1.0
500
0.8
400
0.6
300
0.4
200
0.2
100
Hour Ending
Relative Value of Generation
Trough Plant w/6hrs TES
Solar Radiation
Winter: dispatch power to
meet morning and evening
periods of peak demand
Utility Load, Trough Plant
Output
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
0.0
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour Ending
Relative Value of Generation
Trough Plant w/6hrs TES
Solar Radiation
*Graphs courtesy of Arizona Public Service
CSP Alliance
6
http://www.csp-alliance.org
Solar Resource (W/m2)
Utility Load, Trough Plant
Output
1.8

7. CSP (trough) Water Requirements
• Cooling
– Wet Cooling
– Dry Cooling
• Mirror washing
• Steam cycle cleaning
700-900 gal / MWh
70-90 gal / MWh
~ 50 gal / MWh
~ 50 gal / MWh
Impact of Dry Cooling:
~90% less water with:
• 4-7% cost increase in hot
climates (e.g. Las Vegas, NV)
• 3-5% cost increase in cooler
climates (e.g. Alamosa, CO)
CSP Alliance
7
http://www.csp-alliance.org

8. Thermal Energy Storage
Typical CSP storage is heating a mixture of nitrate salts from 390°C
(troughs) to 560°C (towers). Salt heated in the solar field is placed in
the hot tank. Salt coming from the turbine goes to the cold tank.
*Photos courtesy Abengoa
CSP Alliance
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http://www.csp-alliance.org

9. Trough Power Plant
w/ 2-Tank Molten Salt Thermal Storage
Solar Field
Storage
Power Block
Steam Turbine
Hot
Tank
Heat Exchanger
Cold
Tank
Pump
CSP Alliance
9
http://www.csp-alliance.org

10. Trough Power Plant:
Power Generation
Solar Field
Power Block
Storage
Steam Turbine
Hot
Tank
Heat Exchanger
Cold
Tank
Pump
CSP Alliance
10
http://www.csp-alliance.org

11. Trough Power Plant
Power Generation and Charging Storage
Solar Field
Power Block
Storage
Steam Turbine
Hot
Tank
Heat Exchanger
Cold
Tank
Pump
CSP Alliance
11
http://www.csp-alliance.org

12. Trough Power Plant
Power from Thermal Storage
Solar Field
Power Block
Storage
Steam Turbine
Hot
Tank
Heat Exchanger
Cold
Tank
Pump
CSP Alliance
12
http://www.csp-alliance.org

13. Storage Provides Intraday System
Stability
1000
300
900
250
700
200
600
150
500
400
100
Power Output (MWhe)
Direct Normal Irradiance DNI (W/m2)
800
300
200
50
100
0
0:00
0
1:40
3:20
5:00
6:40
8:20
10:00 11:40 13:20 15:00 16:40 18:20 20:00 21:40 23:20
April 12, 2012 (Time of Day)
*Chart courtesy of Solar Reserve
CSP Alliance
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http://www.csp-alliance.org

14. Storage Promoting Flexibility
• Use of storage can lessen grid ramps (the rate of
increase/decrease in grid system power) and reduce operator
uncertainty due to solar forecast errors.
• High capacity value helps meet resource adequacy requirements
• Plant can provide spinning or non spinning reserves
• Importance of storage increases as grid penetration increases of
wind and solar without storage*
– Little value of storage at low grid penetration of renewable energy
– The benefits of storage at higher renewable penetration can be in the
range of $30-40/MWh relative to renewables w/o storage due to
energy, ancillary services, capacity, power quality and avoided
system costs of integration in recent studies by LBNL and NREL
• CSP with storage enables greater use of PV
* Ref: “The Economic and Reliability Benefits of CSP with Thermal Storage:
Recent Studies and Research Needs”, CSP Alliance Report, Dec 2012.
CSP Alliance
14
http://www.csp-alliance.org

15. Categories of Value
Energy
Ancillary services
(for secondary frequency
control)
Power quality and other
ancillary services
Capacity
Integration and
curtailment costs
compared to solar PV and
wind
CSP Alliance
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Hourly optimization of energy schedules
Subhourly energy dispatch
Ramping reserves
Regulation
10-minute spinning reserves
10-min non-spinning reserves
Operating reserves on greater than 10 minute timeframes
Voltage control
Frequency response
Blackstart
Generic MW shifted to meet evolving system needs
Operational attributes
Reduced production forecast error and associated
reserve requirements
Reduced curtailment due to greater dispatch flexibility
without production losses
Ramp mitigation
15
http://www.csp-alliance.org

16. Solar Collection: Trough Technology
•
Parabolic trough technology uses long parabolic mirrors, with an absorber tube running each mirror’s
length at the focal point. Sunlight is reflected by the mirror and concentrated on the absorber tube.
•
Heat transfer fluid, comprised of oil or molten salts, runs through the tube to absorb the concentrated
sunlight. The heat transfer fluid is then used to heat steam for a turbine/generator or heat storage.
•
Trough systems are sensitive to economies of scale and estimated to be most cost effective at
100 MW or greater.
•
Solar concentration: 75 suns | Operating temp: 390°C |
CSP Alliance
16
http://www.csp-alliance.org

17. Solar Collection: Power Towers
•
Power towers use an array of flat, moveable mirrors, called heliostats, to focus the sun's rays
onto a receiver at the top of a central tower. The energy in the receiver is transferred to a
heat transfer fluid (salt or steam) which is used to heat steam for a turbine/generator or
storage media (salt).
•
Molten salt allows solar energy from daylight hours to be stored to generate steam
throughout the evening. The high operating temperature enables less expensive storage.
•
Due to power block requirements, power towers are sensitive to economies of scale and are
typically most economical at 100 MW or more.
•
Solar concentration: 800 suns | Operating temperature: 560°C
CSP Alliance
17
http://www.csp-alliance.org

18. CSP Plants Under Construction in the U.S.
Solana
Mojave
Genesis
Crescent
Dunes
Ivanpah
Technology
Trough w/6
hrs storage
Trough
Trough
SaltTower
w/10 hrs
storage
Steam
Towers
Capacity
(MW)
280
280
250
110
392
Jobsconstruction
1,600
800
600
1,000
Jobspermanent
85
47
45
86
Location
Arizona
California
California
Nevada
California
DOE Loan
Guarantee
$1.45B
$1.2B
$0.85B
$0.74B
$1.6B
Completion
2013
2014
2013
2013
2013
Developer
Abengoa
Abengoa
NextEra
Solar
Reserve
BrightSource
CSP Alliance
1,000 and 80
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http://www.csp-alliance.org

19. Solana: trough 280 MW
with 6 hrs Storage
Photos courtesy Abengoa
CSP Alliance
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http://www.csp-alliance.org

20. Ivanpah: 3 towers totaling 392 MW
*photos courtesy BrightSource
CSP Alliance
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http://www.csp-alliance.org

21. Ivanpah
CSP Alliance
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http://www.csp-alliance.org

22. Crescent Dunes: 110 MW with 10 hrs storage
*photos courtesy Solar Reserve
CSP Alliance
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http://www.csp-alliance.org

23. Solar Collection
 Direct normal, diffuse, and global solar radiation
 CSP can use only the direct because diffuse can not be effectively focused or
concentrated
SOURCE: Status Report on Solar Thermal Power Plants, Pilkinton Solar International, 1996.
CSP Alliance
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http://www.csp-alliance.org

24. Solar Resource in U.S. Southwest
CSP Alliance
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http://www.csp-alliance.org

25. DOE & BLM: identifying land for CSP
deployment
Approach: a programmatic environmental impact statement
(PEIS)
•
BLM manages 119 million acres in the 6 Southwestern states where the
solar resource is most intense (CA, NV, NM, AZ, CO, and UT)
•
Identification of land that is
appropriate for solar deployment from
technical and environmental
perspectives
•
Streamline evaluation and processing
of solar projects
• Identification of additional transmission
corridors crossing BLM-managed land
• 17 solar zones proposed totaling about
285,000 acres
CSP Alliance
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http://www.csp-alliance.org

26. Cost Reduction: R&D and Deployment
• Sargent & Lundy’s due-diligence
study* evaluated the potential cost
reductions of CSP.
• Cost reductions for CSP
technology will result from R&D
and deployment.
*
CSP Alliance
26
Sargent and Lundy (2003). Assessment of Parabolic Trough
and Power Tower Solar Technology Cost and Performance
Impacts. http://www.nrel.gov/docs/fy04osti/34440.pdf
http://www.csp-alliance.org

27. Importance of Deployment on Cost
Deployment is as more important in
reducing cost as R&D advancements
CSP Alliance
27
http://www.csp-alliance.org

28. DOE’s SunShot Goal*
Reduce the installed cost of solar energy systems to about 6¢kWh
w/o tax incentives, driving widespread, large-scale adoption of this
renewable energy technology
*SunShot Vision Study, Feb 2012,
http://www1.eere.energy.gov/solar/sunshot/vision_study.html
CSP Alliance
28
http://www.csp-alliance.org

29. Paths to SunShot Goal – DOE R&D
• High Temperature Systems – higher operating temperature
increases system efficiency.
– Existing steam systems operate at 390oC – 565oC with 37-42%
efficiency.
– Research focused on supercritical CO2 Brayton operating at 600oC800oC with 50-55% efficiency
• Storage – two tank salt the standard to beat but explore other
options like higher temp storage/heat transfer fluid materials, phase
change and solid materials, including direct steam
• Solar Field – reduce collector cost while maintaining or improving
optical performance
• Receivers – develop selective coatings for high temperature
receivers
CSP Alliance
29
http://www.csp-alliance.org

30. Thank You
Frank “Tex” Wilkins
Executive Director
Concentrating Solar Power
Alliance
Phone: (410) 960-4126
tex.wilkins@gmail.com
CSP Alliance
30
http://www.csp-alliance.org