QBR Update Rick H ATQ, SCS and Electronics

Commercial Readiness of eSolar Next Generation Heliostat
Las Vegas, Nevada, USA
September 17, 2013
Plazi Ricklin
Rick Huibregtse
Mike Slack
Dale Rogers
SCS5 Objectives and Project Status
So far completed:
• Requirements, Trades, Concepts
• Preliminary design with component proto
• Detailed design with up to 4 iterations
hardware & testing
• Design Validation Testing (400+
• 2nd iteration detailed design updates
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
• 2nd iteration detailed design procure & test
• Pilot design release and build
• Smaller volume system component
detailed design
2 year project; pilot capacity installation underway
Ready to fill orders in early 2014
Applications and Deployment of SCS5
• Use of SCS5 in many fields
Power Generation
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
100-MW Molten Salt
46-MW Steam
Large Single Tower
Enhanced Oil Recovery
• 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
GE Flex
Process Heat & Desalination
SCS5 Requirements Driving Design
Performance: Slewing 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)
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)
Operational Temperature
Start within 0.5 seconds of engaging emergency defocus. Bulk salt temperature not to
exceed 600C.  off point 95% of energy in <90 seconds
-10C to 55C
Survival Temperature
RAM: Availability
-40C to 70C
RAM: Operational lifetime
Field shape
Trade 30 year equipment design life with a shorter design life with periodic repair
Hexagonal or square
Location: Site characteristics
Topography: uniformly sloping properties, out of flood plane, not directly on faults
Installation: Size and weight limits
Soils: sand, silt, clay, optional rock/bedrock
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 FEC
O&M: Cleaning
COM: 1GB Fiber based redundant Ethernet
Effective cleaning technology with minimized cost and water usage, operates day or night
Performance: Tracking in wind
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
• 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
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
• Design & Operation minuses -- Change
Long structure members
Clumsy height adjustment
Significant effort for ground preparation
Electrical/electronics built inside
• Superfluous connection points
• Exposed actuation mechanisms
• Non essential features
Operating 25,000 heliostats at Sun Tower since 2009 informs current design
Drive Differentiation: Design, Don’t Buy
• 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
Mass, Excluding Foundation (kg/m2)
Drive Gear Ratio (Azimuth/Elevation)
Operational/Slew Wind Speed – Azimuth (mph) 35/50
Survival Wind Speed Rating (mph)
Operational Temperature Rating (deg C)
-10 to 50
-10 to 55
Reflector area per Heliostat (m2)
Less parts, enclosed, high volume design = good cost and reliability
ST3 Drive
• 100 parts
• 70 unique parts
SCS5 Drive
• 50 parts
• 25 unique parts
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
Moves high volume & high quality reflector
assembly to standard factory site
Reflector Module
Heliostat Structure Details
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
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
Self-leveling, 4 bolts per Heliostat, 2 spikes, no foundation
Multiple Soil
Type Field Tests
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
• 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
SCS5 POD at Sierra
(pointing test)
• System testing summary
Combined effects test
with artificial wind loads
Red = SCS5 Deployments
• Built and deployed heliostats to Sierra
• Use Spectra to calibrate and control
• System performance measurements
show good pointing error
System Optimization through O&M Changes
• Observed problems
Pointing performance
Out of service w/o knowledge
Not calibrated
Missing or broken glass
Artificial Light
Calibration (Patented)
Point source lightbased system
Image of field from
camera view
• Fix:
• Measure pointing performance
at night
• Detect out of service units
same day
• Calibrate at night
• Detect missing reflector area
• Maximize energy collection per
• Reduce spillage
• Identify units not contributing and
repair swiftly
• Don’t calibrate if receiver is not
maxed out
• Ensure clean and maximum
reflector areas
Using software and small heliostats to solve industry issues at low cost
System O&M is a Strong Influence in System Design
• Trade O&M cost vs. Capex
• O&M Challenges and Cost
Failures and replacement
Electric power consumption
• Cleaning capabilities
Rows are simple to clean
Drive-by cleaning proven at Sierra
Developing more effective system
Use less water and labor
O&M Cost Contribution
• SCS5 O&M Features
Cost per m^2
• 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
O&M can be large factor in LCOE, trade O&M vs. Capex
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) • Design to cost targets CAPEX
• Select 100MW 50% capacity MS plant
• Solar receiver and piping system
• Top down allocation for SCS capex
• Shared control room, maintenance building, etc.
• 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
SCS5 POD, Sierra Field 2
Leverage small heliostat cost advantages across entire system
and assure all costs are included
SCS5 Cost Reduction in CapEx and O&M
• Reducing cost from previous
• System advantages
generation by 40%
• Shared wind loads
• Design and optimize as a system
• More reflector area per drive
• Reduce number of unique parts
• Reduced field labor
• Select high volume production
• Reduced electronics and
installation cost
• Design for manufacture during
• Reduced ground preparation costs
concept design
• Construct regular array
• Shift work from the field to the
• Leverage low skill local workers
• Minimal heavy equipment overhead
• Remove nice to haves
Launch Supply Chain and Localization
• High volume components built in factory
• Contract manufacturer with global footprint builds
• 3rd party component vendors selected; currently
centered around Suzhou
Inbound raw material packaging
• Exercise vendors during design validation; prior to
• Components ship ready to install
• Reflector module assembled in factory or at site
• Design control over all aspects of system allows
broad localization
Reflector module line trial parts
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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