Andrew McIntyre, CIH Managing Principal & Co-Founder

1. EHS & Sustainability Considerations in Alternative Energy (Photovoltaic) Market Areas“New Directions in EH&S Practice” 20th Annual CIHC ConferenceDecember 6-8, 2010 Andrew McIntyre, CIH Managing Principal & Co-Founder

2. Presentation Overview • Introduction • What are Photovoltaics? • Example Manufacturing Processes • Chemical & Physical Hazard Overview • Driving DFESH into the Manufacturing Supply Chain • Key Manufacturing and Facility EHS & Sustainability Considerations • Feeding the Utility Grid • Solar Field Impacts and Considerations • Summary

3. Introduction – What are Photovoltaics? • Devices (solar cells) that convert sunlight into direct current (DC) electricity • Consist of thin layers of semiconductor material placed on a silicon (or alternate material) substrate with a protective layer added and wiring integrated to conduct electricity • Very similar to transistors • Solar cells are assembled into modules • Modules are then assembled into larger collections of panels and arrays • Renewable energy source • Do not emit greenhouse gases during “use” phase of life • A means to offset the generation of energy from burning fossil fuels as fossil fuels create significant CO2 emissions • 1GW of PV electricity production will serve the needs of approximately 145,000 average U.S. homes and save roughly 1 million metric tons of carbon dioxide emissions annually

4. Introduction – What are Photovoltaics? • Solar energy liberates excess electrons that then flow to produce electricity

5. Introduction – Why Viewed as a Clean Industry? “A means to offset the generation of energy from burning fossil fuels” Source: “Solar Environmental Impacts”, World of Photovoltaics Magazine. www.worldofphotovoltaics.com

6. Example Manufacturing Processes

7. Introduction - PV Manufacturing Technologies & Related Efficiencies

8. Introduction – PV Manufacturing Product Overview

9. PV End Product Application • Photovoltaic Panel Configuration • Flat‐Plate Solar Panels • The most common type of solar panel • Absorb both direct sunlight and diffuse sunlight reflected from clouds and objects on the ground • Concentrating Photovoltaic (CPV) • A specialized type of solar panel which uses mirrors or lenses to focus high concentrations of direct sunlight onto high‐efficiency solar cells • Cannot absorb diffuse light, so are typically used only in areas with high levels of sunlight such as the Southwest United States. • In order to maintain focus, CPV employs tracking systems, allowing them to follow the sun’s path as it moves across the sky • Tracking systems • Can be single‐axis – which track the sun throughout the day – or dual‐axis, which also adjust to the sun’s elevation in the sky from season to season. • Tracking systems are also occasionally used for flat‐plate systems. • Depending on conditions, tracking systems can add 25 percent or more to the total electrical output of a solar energy system © 2010 EORM, Inc. 9

10. Chemical & Physical Hazard Overview

11. Crystalline Silicon (c-Si) Based PV Cells - Overview • Crystalline silicon-based PV Cells: • Most common of all solar cell types (~80%) • Rooftop applications • Large utility arrays • Crystalline silicon processes relatively simple – model semiconductor manufacturing steps • Crystal Growth • Doped with Phosphorous or Boron • Ingot slicing, lap and polish • Sandwiched between glass or layers of ethyl vinyl acetate and a polymer laminate • Metal grids and contacts added © 2010 EORM, Inc. 11

12. Crystalline Silicon (c-Si) Based PV Cells – Chemical Hazards • Corrosives and Oxidizers • Used for cleaning and etching in open top tanks, baths, etc. • Corrosives • Hydrochloric acid • Hydrofluoric acid • Oxidizing Acids • Nitric acid • Sulfuric acid • Bases • Sodium hydroxide • Oxidizers • Hydrogen peroxide • Engineering Controls • Process enclosures of tanks and baths • LEV

13. Crystalline Silicon (c-Si) Based PV Cells – Chemical Hazards • Metals • Used for electronics (connecting wires, contacts, etc.) • Lead • Zinc • Silver • Copper • Engineering Controls • Process enclosures • LEV

14. Crystalline Silicon (c-Si) Based PV Cells – Chemical Hazards • Irritant Dust • Cutting, sawing, scribing PV Si cells • Production of silicon dust (known as “kerf”) • Engineering Controls • LEV

15. Thin Film (Amorphous) Silicon-Based PV Cells - Overview • Thin film amorphous silicon-based PV Cells • Power low power consumer products • Solar panels • http://www.youtube.com/watch?v=mMQfmUpurJM • Amorphous silicon processes more complex – similar to semiconductor manufacturing steps • Cleaning • Laser and Chemical Etching • Chemical Vapor Deposition (CVD) • Physical Vapor Deposition (PVD) • Ion Implant © 2010 EORM, Inc. 15

16. Thin Film (Amorphous) Silicon-Based PV Cells – Chemical Hazards • Pyrophorics, Flammables, and Toxic Gases • Used for doping thin films • Silane - pyrophoric • Phosphine – toxic and pyrophoric • Arsine - toxic • Phosphorous chloride (POCl3) - toxic • Diborane - toxic • Engineering Controls • Use of sophisticated hazardous gas distribution systems • Used in sealed, pressurized chambers with LEV • Purge gases

17. Illustration – PV Thin Film Fabrication Thin Film a-Si

18. Illustration – PV Thin Film Fabrication Thin Film a-Si

19. Overview – Thin Film PV Manufacturing Steps Potential Health and Environmental Impacts Associated with the Manufacture and Use of Photovoltaic Cells, EPRI, Palo Alto, CA, and California Energy Commission, Sacramento, CA: 2003. 1000095. http://mydocs.epri.com/docs/public/000000000001000095.pdf

20. Thin Film CdTe and CdS-Based PV Cells - Overview • Cadmium Telluride (CdTe) and Cadmium Sulphide (CdS): • Thin film type • Fastest growing share of market (15-20%) • Similar in application and process to thin film amorphous Si PV cells • Can be used together or with other materials for multi-junction thin film PV cells © 2010 EORM, Inc. 20

21. CdTe and CdS-PV Cells – Chemical Hazards • Metals • Used for electronics (connecting wires, contacts, etc.) • Deposition - spray pyrolysis, maintenance, cleaning • Cadmium and cadmium compounds such as CdCl2 • Recognized carcinogen • Nickel • Molybdenum • Engineering Controls • Process enclosures • Sealed, pressurized chambers with LEV • LEV

22. CdTe and CdS-PV Cells – Chemical Hazards • Others • Thiourea (thiocarbamide) and ammonia • Used in electro-deposition (chemical bath) process • Engineering Controls • Process enclosures • LEV

23. CIS and CIGS-Based PV Cells - Overview • Copper or Cadmium Indium Gallium and Selenium - (CIS) and (CIGS): • Thin film type • Small percent of market (~5%) • Processes vary, but usually involve some form of deposition step • Newer approaches involve application using pastes © 2010 EORM, Inc. 23

24. CIS and CIGS-Based PV Cells – Chemical Hazards • Metals • Used for electronics (connecting wires, contacts, etc.) • Deposition, sputtering, etc. • Cadmium • Copper • Indium • Gallium • Selenium • Molybdenum • Engineering Controls • Process enclosures • Sealed, pressurized chambers with LEV • LEV

25. High Efficiency PV Cells - Overview • High-efficiency multijunction cells • Consist of multiple thin films produced using Metal Organic Chemical Vapor Deposition (MOCVD) • Also called cascade or tandem cells • III-V Material (vs silicon) based substrate • Are the highest‐efficiency solar cells currently available, • Expensive to manufacture • Are used when weight and efficiency are at a premium • Satellites, • High‐performance solar‐powered vehicles • Military applications, and • For concentrating PV (CPV) © 2010 EORM, Inc. 25

26. Illustration – Gallium Arsenide (GaAs) PV Concentrator Cell Mfg Metal Organic Chemical Vapor Deposition Process Exhaust Vent Arsine / Phosphine Gas Scrubber Delivery Hydrogen Detector & Fire Sprinkler Gas Handling system mfc N2/ H2 mfc MOCVD N2 Reactor mfc mfc Hydrogen Detector & Ammonia Detector © 2010 EORM, Inc. 26

27. High Efficiency Based PV Cells – Chemical Hazards • Chemicals used • Metal Hydrides • Arsine • Phosphine • Metal Organic Precursors • i.e., Trimethyl Gallium, Trimethyl Indium • Engineering Controls • Process enclosures • Sealed, pressurized chambers with LEV • LEV

28. Nanomaterial-based Cells – Chemical Hazards • Improved efficiencies • Sometimes applied as ink pastes • Nano-scale materials used: • Cadmium • Silicon • GaAs • CdTe • Carbon • Engineering Controls • Process enclosures • LEV • HEPA vacuums

29. Physical Hazards - Ionizing Radiation Sources • Types and Applications: • X-ray machines (XRF, XRD) • Sealed sources • Used for calibration, measurement, inspection • Engineering Controls • Interlocked enclosures • Sealed sources

30. Physical Hazards - Non-Ionizing Radiation Sources • Types and Applications: • Microwave generators • Radiofrequency (RF) generators • Used by some deposition tools • Engineering Controls • Shielding

31. Physical Hazards - Laser Sources • Types and Applications: • Used at many PV facilities • Up to Class 4 lasers • Applications • Cutting, scribing processes • Measurement • Engineering Controls • Interlocked enclosures • Controlled access • Non-reflective surfaces

32. Robot and Robotics Automation • Engineering Controls • Restricted Work Envelope • Safety interlocks • Interlocked barriers, light curtains, pressure sensitive mats, etc.), • Causes all robot motion to stop and removes power from the robot drive actuators • Teach pendant • Allows personnel to program the robot from within the safeguarded space around the robot • Robot speed is limited to 10 inches/sec in “teach mode”

33. EHS&S Solutions – Driving DFESH into Supply Chain

34. EHS&S Solutions – Driving DFESH into Supply Chain • Supply Chain Design for Environment, Safety and Health Program • Hold capital equipment suppliers building tools for the PV Industry accountable for safe design and delivery • Safer, more reliable process equipment with appropriate EHS control technology incorporated will: • Prevent injuries and minimize environmental impact • Increase speed of EHS start up approval and minimize expensive (EHS) retrofits • Reduce manufacturing downtime due to EHS concerns associated with maintenance activities © 2010 EORM, Inc. 34

35. Recap - Manufacturing & Facility EHS&S Considerations

36. Recap - Key EHS&S Considerations - Manufacturing • Physical Safety Considerations • Fall protection • Confined space entry • Cranes and hoists • Machine guarding • Robot and Robotic Systems • Industrial Hygiene • Robust Control of Carcinogens • Surface Contamination Control for Cadmium and Arsenic • Promotion of excellent housekeeping practices © 2010 EORM, Inc. 36

37. Recap - Key EHS&S Considerations - Manufacturing • Hazardous Energy Control • Material handling • Conveyor safety • Manual Handling • Glass Industry experience leveraged • Preventive and Corrective Maintenance • Large subsystem components • Noise • Increase in noise from larger support equipment • Can it be attenuated? © 2010 EORM, Inc. 37

38. Recap - Key EHS&S Considerations - Facility • Facility • Impact of Larger Equipment Footprint • Enough space? • Increased utility requirements such as power, exhaust (both LEV and heat) • Local Jurisdiction Permitting • Timely submission to avoid startup delays • Environmental • Abatement systems • New hazardous waste stream(s) • Product Recycling © 2010 EORM, Inc. 38

39. Feeding the Utility Grid

40. Feeding the Utility Grid - Background • PV arrays consist of groups of PV modules called “tables” • Each table consists of 45 modules and measures approximately six feet wide by 60 feet long • PV arrays are designed to withstand earthquakes and ground movement © 2010 EORM, Inc. 40 40

41. Feeding the Utility Grid – Existing - DeSoto Energy Center - Florida • At 25 MW peak output, the DeSoto Next Generation Solar Energy Center in DeSoto County, FL is currently the largest PV installation in the United States • The facility came online in 2009 and generates over 42,000 megawatt‐hours of electricity each year (Photo—Florida Power & Light) © 2010 EORM, Inc. 41 41

42. Feeding the Utility Grid – Current Project • Topaz Solar Farm • Location • Carrisa Plains, CA in San Luis Obispo County • Size • 4500 Acre site • Production Output • 550 Megawatts of Power • Will produce sufficient electricity to power 160,000 homes through delivery of approximately 1,100 gigawatt-hours (GW·h) annually of renewable energy © 2010 EORM, Inc. 42 42

43. Feeding the Utility Grid – Current Project • Topaz Solar Farm • Displaces 290,000 metric tons of carbon dioxide annually which equals the removal of 55,000 cars off the road annually • Power will be sold to PG&E and will help PG&E customers meet the State’s Renewable Portfolio Standard (RPS). • California strategic goal of >33% of power coming from renewable energy sources by Year 2020 © 2010 EORM, Inc. 43 43

44. Solar Field EHS&S Impacts and Considerations

45. Feeding the Utility Grid – EHS&S Impacts Requiring Consideration • Environmental and Safety Impacts • Agriculture • Air Quality • Biological Resources • Geology, Soils, and Seismicity • Hazards and Hazardous Materials • Hydrology and Water Quality • Land Use and Planning • Noise • Population and Housing • Public Health and Safety • Public Services • Traffic and Transportation • Utilities © 2010 EORM, Inc. 45 45

46. Feeding the Utility Grid – Operational EHS Compliance • Monitoring and Maintenance • Focused on management of lighting, reflectivity, noise, heat, materials storage and cleanup, safety, and repair • Supported by small crew – Expect ~15 staff • Primary EHS Considerations • Safety • Heat stress, sunburn, appropriate EAP, contact with wildlife • Environmental • For this California project, a PV Module end-of-life program is in place - supported by a pre-funded module recycling program © 2010 EORM, Inc. 46 46

47. Wrap Up and Summary Points • Continued demand for energy with distinct environmental benefits over traditional energy generating technologies • Essential that the PV industry fulfills the perception of being a green industry • Imperative that the PV industry learns from the past EHS&S pitfalls encountered during the expansion of similar high-technology industries • Experience with the semiconductor industry over the last three decades has provided a clear EHS&S roadmap for the PV industry to follow 47 47

48. Wrap Up and Summary Points • Although EHS&S may fall down on the list of priorities during periods of rapid growth, experience demonstrates that small investments now will produce huge benefits later • Mitigation or avoidance of EHS issues can be addressed with the proper planning and implementation of DFESH into the PV Supply Chain • Given the PV industry’s green reputation, a strong commitment to world-class EHS&S management systems is a critical business priority 48 48

49. Wrap Up and Summary Points In summary, the PV industry has both the opportunity and the business imperative to strive for world-class performance in implementing sustainable environmentally responsible controls and work practices 49 49

50. EORM PV EHS&S Articles –Photovoltaic Times