Commercial Readiness of eSolar Next Generation Heliostat

1. Commercial Readiness of eSolar Next Generation Heliostat Las Vegas, Nevada, USA September 17, 2013 Plazi Ricklin Rick Huibregtse Mike Slack Dale Rogers

2. SCS5 Objectives and Project Status • 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 • 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 underway Ready to fill orders in early 2014

3. 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 Power Generation 100-MW Molten Salt 46-MW Steam Large Single Tower Enhanced Oil Recovery ISCC Process Heat & Desalination GE Flex

4. SCS5 Requirements Driving Design Only few requirements dominate the design: Wind forces, operating temperature, installation location

5. 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

6. 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 SCS5 • 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 ST3 Operating 25,000 heliostats at Sun Tower since 2009 informs current design

7. 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 • ST3 Drive • 100 parts • 70 unique parts 14” • SCS5 Drive • 50 parts • 25 unique parts Less parts, enclosed, high volume design = good cost and reliability

8. 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 Reflector Module Moves high volume & high quality reflector assembly to standard factory site RMAS

9. 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 conditions TriPod Configuration Multiple Soil Type Field Tests Self-leveling, 4 bolts per Heliostat, 2 spikes, no foundation

10. 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 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 Combined effects test with artificial wind loads Red = SCS5 Deployments

11. System Optimization through O&M Changes • 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 Artificial Light Calibration (Patented) Point source light-based system Image of field from camera view • 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 Using software and small heliostats to solve industry issues at low cost

12. 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 • 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

13. 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 included SCS5 POD, Sierra Field 2

14. SCS5 Cost Reduction in CapEx and O&M • 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 • 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

15. 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 Inbound raw material packaging development Reflector module line trial parts

16. 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