TECHNOLOGY INNOVATIONS IN PV MANUFACTURING DR. ATUL GUPTA,

DIRECTOR R&D/PRODUCT DEVELOPMENT

Suniva overview

Our approach to innovations

– Why, what and how?

– Innovating through tough times

– Key challenges

– Technology options

Impact on Metrology Equipment Makers

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OUTLINE

WHO WE ARE

Manufacturer/developer of high-efficiency, crystalline silicon PV cells & modules

– High-Efficiency Cells: Averaging 19+% in production; over 20% in pilot; roadmap to over 22% by 2015

– High-Power Modules: 16+% in production; 60 cell modules up to 270W, 72-cell modules up to 315W

– Deep R&D Capabilities: In-house cell and module labs; collaboration with UCEP at Georgia Tech

– Cost Competitiveness: Cost competitive with top-tier Asian manufacturers, with higher quality

– Manufacturing Capacity: 170 MW in the U.S.; 500 MW in Asia

– Buy America Compliant Modules: one of the highest U.S.-content modules on the market

– Market focus: Commercial, residential and utility applications in the U.S., Asia and Europe

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Investor Backing:

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SUNIVA® INNOVATION IN THE VALUE CHAIN

Silicon Ingot Wafer Systems Integrators

Cells Modules

Balance of System Solutions

Unique Partnerships

The solar cell is the “DNA” of

any PV system, and hence the key driver of value

Making high-quality, high-power solar cells and

modules using U.S.-based technology at

affordable costs to address the world’s energy needs

NEW TECHNOLOGY INNOVATIONS

KEY ELEMENTS FOR INNOVATION

Innovation

Need/Desire to innovate

Foundational principle

Visionary leadership

Knowhow + capability

Deep technical expertise

Solid financial backing

Infrastructure

Fully equipped R&D lab

Access to GT equipment

Access to Pilot Production line

Access to new technologies

Multiple collaborations

Successful track record

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Deep Roots, Continued Collaboration

Suniva has access to over $50M worth of advanced research equipment at UCEP/Georgia Tech

Suniva benefits from a budget of over $43M of PV-related research programs funded partly by the U.S. DOE

90 kW rooftop installation on Georgia Tech’s Clough Center 90 kW rooftop installation on Georgia Tech’s Clough Center

1985: PV Program Established at Georgia Tech

Department of Energy

provided funding

1992: University Center of

Excellence Established

2007: Suniva Founded

Dr. Ajeet Rohatgi Suniva Founder & CTO

Distinguished Professor of Electrical Engineering at Georgia Tech

John H. Weitnauer, Jr. Chair Georgia Research Alliance Eminent

Scholar 16 world-record cells 42 patent families 400+ publications Westinghouse Engineering

Achievement Award IEEE Cherry Award, 2003 NREL Rappaport Award, 2003 5 Most Influential in Renewable

Energy, 2008 Named “Champion of PV”, 2010

Q. Which Ones to Pursue?

A. Varies, based on where you are in the value chain!

Lower $ (@same performance) for Materials Suppliers

Lower $/Wp (cells/panels) for Cell/Module makers

Lower $/Wp (Installed system cost) for System Installers

Lower LCOE for EPCs

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TECHNOLOGY INNOVATIONS

New Technologies need to support the declining module based on the learning curve (~21% for every doubling of capacity)

SURVIVING AS A PANEL MANUFACTURER

Source : ITRPV 2013

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Solar Photovoltaic Module Revenues to Rebound to $32 Billion by 2017, According to NPD Solarbuzz

Solar Photovoltaic Demand to Reach 31 Gigawatts in 2013, According to NPD Solarbuzz

Solar Photovoltaic Demand in 2012 Falls Short of 30 GW Mark, Reports NPD Solarbuzz

World Solar Photovoltaic Market Grew to 27.4 Gigawatts in 2011, Up 40% Y/Y

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WHAT SHOULD WE PLAN FOR?

Plan for the Module Prices to decline (21.5% for every doubling of installed capacity) despite recent reports of recovery and growing demand

Module manufacturers should plan for a $0.03 to $0.05/Wp annual decline in ASPs over the next 2-5 years

Simple MATH : 2012 installed capacity ~110GW , installation rate ~31GW/year 2012 ASP ~0.70/Wp ~3 years to double installed capacity $0.70/Wp$0.55/Wp (21.5% decline) (=$0.05/Wp Annual Decline!)

A. Two (usually conflicting) approaches!

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HOW DO WE GET THERE?

Lower the Cost of Manufacturing

Get Higher Performance

1. Lower cost materials

1. Cheaper polySi, thinner Wafers, cheaper glass/EVA/frame etc.,

2. Eliminate non-value add steps

1. Junction Isolation, Extra Cleans (wafering/cell processing), co-anneals etc.

3. Improved manufacturing yields/Tighter Process Control

1. BatchSemibatch wet processing, SPC, inline metrology etc.

4. Improved tool/factory utilization

1. WIP management, Fab Automation, 2x loading, larger PECVD boats, etc.

5. Lower cost of ownership

1. Lower material usage per wafer (Ag paste etc.) , solar grade materials

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LOWERING THE COST OF MANUFACTURING

1. Generate More : Let More Light Into the Absorber

1. Cell level : Improve texturing, optimize ARC, improve back surface reflectance, minimize front grid shading

2. Module Level : AR Glass, high Transparency EVA, improved back reflector

2. Lose Less : Reduce Recombination Losses

1. Higher Lifetime material

2. Improved Emitter technology (Lighter doping), e.g. Implant or High Rsheet POCl3 processes

3. Improved Passivation Process (less Surface recombination): Oxide/SiNx stacks or AlOx/SiNx stack, reduced Metal contact

3. Collect More : Reduce Resistive Losses

1. Optimize Front Grid/BBR configuration (Increase as technology matures)

2. Higher Conductivity Interconnect Ribbons

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INCREASING CELL/MODULE EFFICIENCY

INNOVATIONS IN CELL TECHNOLOGY

2008

Eff

icie

ncy

< 6months Startup

Industry leading performance

2-bus bar cell design

Proprietary recipes

Process optimization

Material and equipment improvements

3-bus bar design

ARTisun Select 19.0%

ARTisun Star

>20%

Advanced Metallization

Finer Gridlines

Higher efficiency at Lower Cost

ARTisun Select + 19.5%

Proprietary >20% cell structure

Back side improvements

NREL certified over 20%

Proprietary Cell and Process

World’s First adopter of Implant

Front side emitter improvement

Process Simplification

ARTisun 18.0%

ARTisun 17%

ARTisun Select 19.0%

ARTisun Star 20% ARTisun

Select + 19.5%

Execution Optimization Innovation Simplification Collaboration

Current Production Pilot Validation

20.4% in LAB

N-type substrate

Back contact eliminates all shading

Integrated front & back side enhancements

Simplified 12-step process

ARTisun IBC

> 22%

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ADVANTAGES OF ION-IMPLANTATION

Higher Performance (gained 1% abs. in cell efficiency)

– Formation of high quality emitter with no dead layer

– Enables high quality passivation through in-situ oxidation during anneal step

– Simple and better controlled process enables tighter binning of high value product from the line

Lower Costs due to Process Simplification :

– Elimination of non-value add steps like edge isolation and dopant glass removal

– Improved Yields (gained 2% in overall yield by eliminating edge isolation)

Strategic Fit (access to advanced device structures)

– Enables low cost Boron doping solution

– Compatible with Patterned implantation for advanced device structures

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World’s First PV Production Implanter

Ion Implanters Norcross, Georgia

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PERFORMANCE DISTRIBUTION FROM A TYPICAL DAILY PRODUCTION RUN AT SUNIVA

0

5000

10000

15000

20000

25000

30000

18.7% 18.8% 18.9% 19.0% 19.1% 19.2% 19.3% 19.4% 19.5% 19.6%

Nu

mb

er

of

Ce

lls

Staying Ahead of the pack is critical to have high factory utilization

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Minimize Material Costs In Cell Processing

– Particularly Front Ag pastes (~45% of materials) through Screen Optimization

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NEXT STAGE OF EVOLUTION

The Optimum Screen for Efficiency is more expensive than the one optimized for lowest $/Wp

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OPTIMIZING FRONT PATTERNS

Max. Efficiency

Lowest $/Wp

Finer linewidths will enable higher efficiency at lower costs!

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SCREEN INNOVATIONS : FINER IS BETTER

Advanced cell designs need additional processing steps (increased cell conversion costs) that needs to be offset by efficiency gains

Falling Cell/Module Prices reduce this leverage making adoption harder!

WHAT ABOUT HIGHER EFFICIENCY DESIGNS?

Increased conversion cost/ wafer

Wafer + Cell Processing + Module BOM

New Technologies Must Eliminate “non-value add” steps or “accomplish more with less”

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PERC cell on p-type substrate (In Pilot validation)

Key Elements

1. Improved Back passivation

2. Back reflector (Cheap coating)

3. Local contact formation (Ablation or LFC)

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NEXT GENERATION CELL TECHNOLOGY

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CHALLENGES IN MODULE MANUFACTURING

1. Reliability – Supports a 25 Year Service Life (and beyond) 2. Bankability – Independent Verification of Reliability 3. Cost – Both Initial and LCOE 4. Performance – As it contributes to cost and competitiveness

SUNIVA’S ENHANCED TEST PROTOCOLS

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Ensure safety and reliability of products

Demonstrate long-term module performance

Validate new cell designs & materials

Ensure we incorporate new materials

without a higher risk of reliability failures

Validate changes in process specifications

Tier 1 Competitors

UL1703 Safety Standard

IEC 61215 Performance Standard

IEC 61215 Performance Standard

Fraunhofer Extended Reliability Tests

(In addition to IEC and UL!)

UL1703 Safety Standard

Suniva Material

Qualification (In addition to UL, IEC and

Fraunhofer!)

On-going Suniva module lab

quality and reliability testing of sample production

Why we do testing!

Examples of Product Failures

Failure: This sample failed after only 300 hours in the damp heat chamber

Hidden Cracks leading to EVA discoloration: AKA Snail Trail

Example of a PV module with burnt diode

Cell Hot Spots Causing Burn Marks Cell Current Mismatch Mechanical Load Failure

25 Industry needs Reliable and Faster measurements/tests

Confidential & Proprietary © Suniva®, Inc. 2012

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MODULE INNOVATIONS : MATERIAL COST REDUCTION

Success of a Solar Cell/panel Manufacturer is contingent upon continued innovations in technology/manufacturing

– Ability to simplify processes and remove redundant steps with Innovative processing technologies

– Cost optimization/reduction without compromising quality and reliability is the key requirement for success in this industry

New Device Technologies need to accomplish more for adoption

– Shrinking lever of wafer and module BOM costs

– Focus on technologies/processes that give “2 for 1”

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SUMMARY

Collaborative Development Efforts between Equipment and Cell/panel manufacturers are Required to Ensure Adoption

Near Term

1. Universal IV testing

2. Full wafer characterization

3. Cosmetics/Quality specs

Longer Term

1. Integrated tool level SPC

2. Defect characterization and root cause analysis

3. Materials qualifications

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OPPORTUNITIES FOR METROLOGY COMPANIES

Near Term

1. Interconnect ribbon reliability

2. Optimized matching of cells during stringing/assembly

3. 100% EL/PL inspection

Longer Term

1. Accelerated reliability testing

2. Warranty rating for each module

MODULE MANUFACTURING CELL MANUFACTURING

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