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

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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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