Commercial Readiness of eSolar Next Generation Heliostat
Las Vegas, Nevada, USASeptember 17, 2013
Plazi RicklinRick Huibregtse
Mike SlackDale Rogers
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2013
SCS5 Objectives and Project Status
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So far completed:• Requirements, Trades, Concepts• Preliminary design with component proto
types• Detailed design with up to 4 iterations
hardware & testing• Design Validation Testing (400+
verifications)• 2nd iteration detailed design updates
Currently:• 2nd iteration detailed design procure & test• Pilot design release and build• Smaller volume system component
detailed design
2 year project; pilot capacity installation underwayReady to fill orders in early 2014
Objectives:• Provide a low cost robust Heliostat• Develop a high volume industrial heliostat SYSTEM• Leverage previous generation knowledge• Design for expanded geographic regions• Develop design and supply chain concurrently• Shift most work into a factory• Take prudent risks to meet aggressive cost target• Design Heliostat as part of bigger plant system• Minimal departure from legacy product• Optimize for eSolar Molten Salt plants• Support legacy eSolar and 3rd party plants• Backwards compatible with Controls Software• Support pre-existing receiver designs
Applications and Deployment of SCS5
• Use of SCS5 in many fields• Scalable power ratings 5-50MW• Various receiver designs external/cavity• Various coolants steam, air, molten salt• Various locations S.W. US, MENA• Square, surround, north only
• Deployment of SCS5• Short lead time from factory• Completes ground preparation• Install many in parallel/labor linearity
• Application Engineering• Size a field for local DNI conditions• Design field layout for the receiver• Locate ancillary equipment• Adapt to local needs
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ISCC
Enhanced Oil Recovery
Process Heat & Desalination
Power Generation
GE Flex
100-MW Molten Salt
46-MW SteamLarge Single Tower
SCS5 Requirements Driving Design
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Requirement SCS5
Performance: Tracking in wind 0 to 18 mph (100% of SCS design); 29 mph (97% of SCS design); 35 - mph (91% of SCS); 35+mph (68% of SCS) ; 42 to 45 mph (0% of SCS, but able to wind stow)
Performance: Slewing in wind 45[elevation]/54[Azimuth] mph (10 min average, add durst curve gust factor)
Performance: Survival in wind (any orientation) 45 mph (10 min average, 1.51 gust factor)Performance: Survival in wind (stowed) 110 mph (system)Performance: Pointing Error (low wind) ≤ 1.5 mrad RMS (accounted for in performance budget)
Performance: Slope Error Reflector Metric <1.9 (beam quality measurement tied to spillage)
Performance: Emergency Off-point (defocus) Start within 0.5 seconds of engaging emergency defocus. Bulk salt temperature not to exceed 600C. off point 95% of energy in <90 seconds
Operational Temperature -10C to 55C
Survival Temperature -40C to 70CRAM: Availability 99%
RAM: Operational lifetime Trade 30 year equipment design life with a shorter design life with periodic repair replacement
Field shape Hexagonal or square
Location: Site characteristics Topography: uniformly sloping properties, out of flood plane, not directly on faultsSoils: sand, silt, clay, optional rock/bedrock
Installation: Size and weight limits High volume components can be installed with manual labor and hand tools
Interface to Plant: Power and COM Power: local custom AC input 50-60Hz 3 phase, 50kW per FECCOM: 1GB Fiber based redundant Ethernet
O&M: Cleaning Effective cleaning technology with minimized cost and water usage, operates day or night
Only few requirements dominate the design:Wind forces, operating temperature, installation location
Systems Design Approach and Opportunities
• Optimize heliostat as a system • Build in the right redundancy at the right location• Remove as many connectors as possible• Optimize for many receiver technologies
• Move cost from component to system• Especially important with higher volume of small heliostats• Example: some controller work is on central server, each drive needs less
complexity
• Use operating experience• Optimize system for energy delivery maximum (easy to clean)• Design system to detect failures immediately, MTTR same night re-calibrate
• Mechanical design is simple, leverages system software• Small drives cannot self-damage• Can accurate calibrate and track without sensors or encoders
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Past Experience Informs Current Design
• Design & Operation pluses -- Keep• Small components, easy install• Stiff structure, maintain rigidity• Each facet is actuated• Each heliostat has control & aim point• Low installation precision, calibrate• High density, AZ/EL, hex packed
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• Design & Operation minuses -- Change• Long structure members• Clumsy height adjustment• Significant effort for ground preparation• Electrical/electronics built inside
structure• Superfluous connection points• Exposed actuation mechanisms• Non essential features
Operating 25,000 heliostats at Sun Tower since 2009 informs current design
SCS5
ST3
Drive Differentiation: Design, Don’t Buy
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ST3 Drive• 100 parts• 70 unique parts
SCS5 Drive• 50 parts• 25 unique parts
Less parts, enclosed, high volume design = good cost and reliability
• Only procured assembly is the motor• Parts designed to share existing industry volume• Ability (and challenge) to engineer
• Gear train• Backlash compensation• Drive controller
• Purchased assemblies small part of total cost• Use same size drive for more aperture area• More mass efficient 14”
Characteristic ST3 SCS5
Mass, Excluding Foundation (kg/m2) 32.1 20.0
Drive Gear Ratio (Azimuth/Elevation) 498:1/498:1 1800:1/1800:1
Operational/Slew Wind Speed – Azimuth (mph) 35/50 35/45
Survival Wind Speed Rating (mph) 110 110
Operational Temperature Rating (deg C) -10 to 50 -10 to 55
Reflector area per Heliostat (m2) 1.1 2.2
SCS5 Reflector Module and Assembly System
• Reflector module characteristics• Reflect light in known pattern• Use simple frame and flat glass• Make optical quality in assembling
process with controlled bias
• Reflector Module Assembly System• Fully automated with glass, frame
adhesive inputs; RM output• 100% automated inspection• eSolar process developed and
automated by vendor• Supports remote, near site, on site• Production equipment is modular and
fits in sea-containers• Developed by automotive assembly
line design/build house
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Moves high volume & high quality reflector assembly to standard factory site
Reflector Module
RMAS
Heliostat Structure Details
Minimum capabilities• Interface with the ground• Secure the drive• Stiff enough for pointing precision• Strong enough for survival loads• Tolerant of field slope and soil
conditions Multiple Soil Type Field Tests
TriPod Configuration
Self-leveling, 4 bolts per Heliostat, 2 spikes, no foundation
Underlying design: • Triangle with three heliostats• Galvanized steel, common gages• Rapid assembly with pre installed
fasteners (4 per H.S.) and simple tools• Float on ground with spike for side load• Sourcing: simple to localize
SCS5 Component and Systems Testing
• Component testing Summary• Combined effects tests on system• Halt and EMI tests on electronics• Hail, extreme operating condition tests on
reflector• Water and Dust ingress on all components• Structure stiffness and anchoring in various
soils• Tested >10 full prototype heliostats in
various sets, prior to pilot build
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SCS5 POD at Sierra (pointing test)
• System testing summary• Built and deployed heliostats to Sierra
SunTower• Use Spectra to calibrate and control
Heliostats• System performance measurements
show good pointing error
Red = SCS5 Deployments
Combined effects test with artificial wind loads
System Optimization through O&M Changes
Using software and small heliostats to solve industry issues at low cost11
Image of field from camera view
Artificial Light Calibration (Patented)
Point source light-based system
• Observed problems• Pointing performance• Out of service w/o knowledge• Not calibrated• Missing or broken glass
• Fix:• Measure pointing performance
at night• Detect out of service units
same day• Calibrate at night• Detect missing reflector area
• Maximize energy collection per CapEx• Reduce spillage• Identify units not contributing and
repair swiftly• Don’t calibrate if receiver is not
maxed out• Ensure clean and maximum
reflector areas
System O&M is a Strong Influence in System Design
• Trade O&M cost vs. Capex• O&M Challenges and Cost
• Consumables• Failures and replacement• Electric power consumption• Cleaning
• SCS5 O&M Features• System self-monitoring and reporting• Low skill, low overhead unit replacement• Line replaceable units are
• Structure, Drive, Reflector Module• Components are hot-pluggable• Component replaced by 2 technicians in 30mins• Redundancy built in at optimal system level• 3rd Party drive/electronics rebuild/repair
• O&M challenges• Assure high MTTF via simple electrical system
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• Cleaning capabilities• Rows are simple to clean• Drive-by cleaning proven at Sierra• Developing more effective system• Use less water and labor
O&M can be large factor in LCOE, trade O&M vs. Capex
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Cost
per
m^2
O&M Cost Contribution
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System Cost: Definitions & Discussion• SCS5 cost reporting includes
• Ex Works• Product cost + Assembly costs + Packaging
• Shipping (Ex Works to lay down yard)• Installation
• Ground preparation +labor + logistics• Associated ancillary equipment and civil work• Licensing fees• Maintenance tools, with cleaning equipment
• Excluded from Solar Collector Scope• Plant work: power block to FEC (power and fiber)• Solar receiver and piping system• Shared control room, maintenance building, etc.
• Design to cost targets CAPEX• Select 100MW 50% capacity MS plant• Top down allocation for SCS capex• Fixed flux, known SCS performance• Have line of sight to target
• Design to cost targets O&M• Top down allocation from MS plant• Results in $3/m2 target• Currently at target at reference site• Includes 20% overhead for plant
management Leverage small heliostat cost advantages across entire system
and assure all costs are includedSCS5 POD, Sierra Field 2
SCS5 Cost Reduction in CapEx and O&M
• Reducing cost from previous generation by 40%
• Design and optimize as a system• Reduce number of unique parts• Select high volume production
processes• Design for manufacture during
concept design• Shift work from the field to the
factory• Remove nice to haves
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• System advantages• Shared wind loads• More reflector area per drive• Reduced field labor• Reduced electronics and
installation cost• Reduced ground preparation costs• Construct regular array• Leverage low skill local workers• Minimal heavy equipment overhead
Launch Supply Chain and Localization
• High volume components built in factory
• Contract manufacturer with global footprint builds drive
• 3rd party component vendors selected; currently centered around Suzhou
• Exercise vendors during design validation; prior to pilot
• Components ship ready to install
• Reflector module assembled in factory or at site
• Design control over all aspects of system allows broad localization
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Reflector module line trial parts
Inbound raw material packaging development
Commercial Readiness of eSolar Next Generation Heliostat
• Project started Feb 2012
• Adding pilot capacity at vendors now
• We are meeting our cost goals
• Have a reliable heliostat, has performance, is affordable
• Great process example of system-level thinking for all aspects of the project
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