The document describes the Ivanpah Solar Electric Generating Facility, a solar thermal power plant located in California. It consists of 3 separate power plants using solar tower technology, with a total capacity of 392 megawatts. Over 173,000 heliostat mirrors focus sunlight onto boilers located on top of 340-foot towers, producing steam that drives electricity-generating turbines. The project required extensive engineering to address challenges like wind-induced vibration, and helps avoid thousands of tons of carbon emissions annually through clean solar power generation.

1. WHAT IT TAKES TO HARNESS THE SUN
IVANPAH SOLAR TOWER DESIGN
Kristin M. Santamont P.E.
Senior Civil Engineer, Bechtel Corporation
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2. IVANPAH SOLAR ELECTRIC GENERATING FACILITY
Location
San Bernardino County, California, USA
45 miles South West of Las Vegas
Customer
Solar Partners
Scope of Service
Engineering
Procurement
Construction
Startup
Project Completion
2013
Units and Megawatts
3 separate power plants totaling 392MW
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3. “GREEN” POWER GENERATING FACILITY
363,000 tonnes of CO2 emissions
avoided each year. Equivalent to
70,000 cars
140,000 homes powered by the
Ivanpah facility
Low impact construction
techniques © Bechtel 2012 | 3

4. TYPICAL UNIT
SRS
G
Air Cooled
Condense
r
Tower
Mirror
Field
Steam Turbine
Generator
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5. PROJECT SITE
1
2
3
Project Size 3,600 Acres
Project Capacity Unit 1 = 126 MW
Units 2 & 3 = 133 MW
Solar Field Size Unit 1 = 895 acres
Unit 2 = 1078 acres
Unit 3 = 1209 acres
Number of
Heliostats
Total = ~173,500
Unit 1 = 53,500
Units 2 & 3 = 60,000
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6. 173,500 HELIOSTATS
Enough reflective area to cover
approximately 600 football fields
Enough mirrors to replace all the
windows in the Empire State
Building…54 times
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7. 3,600 ACRE SITE
Manhattan
Island
1
2
3
 ~ 6 square miles
 Roughly 25% the
size of Manhattan
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8. © Bechtel 2012 | 8

9. SOLAR TOWER STRUCTURE
 120’ tall Solar Receiver Steam Generator
(SRSG)
 54’ x 54’ footprint
 Each SRSG receives solar flux from mirror field
 Conventional steel braced frame
 339’ tall Tower
 70’ x 70’ footprint at base
 45’ x 45’ main tower footprint
 Column splices located for modular erection
 Concrete Foundation
 120’ x 120’ in plan
 9’ thick mat © Bechtel 2012 | 9

10. SOLAR TOWER
 1,800 tons of structural steel
 9 Tiers ~40’ tall
 Lowest 4 Tiers are “stick built”
 5 Tiers Ground Assembled as Modules
 Columns are 36” f pipe sections
 API 5L X56 material
 1 ½” or 2” wall thickness
 2” f A354 Grade BD bolts in splices
 HSS16 square vertical braces
 Traditional floor framing
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11. TOWER STEEL ERECTION
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12. TOWER COLUMN SPLICES
 Each column splice utilizes an identical circular
pattern of 16 2”f A354 Grade BD bolts
 Extra 4 bolts for shear loads at discrete locations
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13. SRSG CONFIGURATION
Superheater Panel
Reheater Panel
Steam Generator
Panel
Protection Panel
Protection Panel
 3 Stage Steam Generator
 700 tons of structural steel
for internal framing
 Total weight including piping
& equipment ~2,000 tons
 Traditional framing
geometry and member sizes
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14. SRSG CONFIGURATION
 Highly congested
volume
 External water walls
with piping, headers
and associated
valves
 Contains steam
drum, silencers,
access platforms,
etc.
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15. SOLAR RECOVERY STEAM
GENERATOR (SRSG)
 “Modularized” in 5 Tiers
 Ground Assembled and transported
to Tower
 Lifted in thirds due to weight limits
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16. STRUCTURAL DESIGN
 2007 California Building Code
 Seismic Design Category C
 Design Wind Speed 85 mph
 Operating wind speed of 30 mph
 Flexible Structure Governed by
Wind
 Flexible Structure
 Fundamental Period 3.3 seconds
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17. VORTEX SHEDDING
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18. WIND TUNNEL TESTING
 Boundary Layer Wind Tunnel Laboratory at
University of Western Ontario
 Performed a Rigid Model Test
 The measured cross-wind loads ~3 times
calculated along-wind code prescribed load
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19. TUNED MASS DAMPER
 Changing foundation and stiffening
structure deemed not practical
 Opted for Tuned Mass Damper
Solution
 Required minimum 5% of critical
damping to mitigate cross-wind
response to an acceptable level
 Other TMD requirements:
 30 year design life
 Operating temperature range 10oF –
o
Idealized TMD with
Suspended Mass &
Dashpots
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20. TUNED MASS DAMPER
 Limited space in SRSG for
addition of TMD.
 11’-4” X 11’-4” X 20’-6” volume
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21. TUNED MASS DAMPER FINAL DESIGN
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22. TUNED MASS DAMPER INSTALLATION
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23. © Bechtel 2012 | 23

24. HELIOSTAT ASSEMBLY AREA
2 Pad Bonding
Buildings
Heliostat Storage
& Pit Lane
Material
Laydown
Assembly Building
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25. HELIOSTAT TRANSPORTATION
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26. Record Number of
Pylons Inserted in One
Day =
711
PYLON INSTALLATION
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27. Record Number of
Heliostats
Installed in One
Day =
512
HELIOSTAT INSTALLATION
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28. CURRENT CONSTRUCTION
STATUS
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29. © Bechtel 2012 | 29
CURRENT
CONSTRUCTION STATUS

30. ACKNOWLEDGEMENTS
 Boundary Layer Wind Tunnel Laboratory
 GERB Vibration Control Systems
www.ivanpahsolar.com
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