module quality assurance: risk mitigation and safeguarding ... · pdf filemodule quality...

SPI 2016: PV Magazine Quality Roundtable

13 September 2016

Module Quality Assurance: Risk Mitigation and Safeguarding Project Value

countries27Client engagements in

125+solar factories worldwide

Audited

employees

Tech

nica

lAdv

isor

yS

upplyC

hain M

anagement

60Over

More than Engineering Services

Quality AssuranceCertified by Proud member of

Over

8GWexperience

A presence in

8Over

countries

8 years history

35 engineers

CEA is a solar PV advisory firm that is able to provide unrivaled insight into themanufacturing process to ensure the success of solar energy projects worldwide

2

2008 2009 2010 2011 2012 2013 2014 2015 2016

ChileMexicoPhilippines

USA CanadaGermanyFranceIndia

United Kingdom The Netherlands Italy

ChinaSouth KoreaJapan

SpainPortugalRussia

NorwaySingaporeAustralia

ShanghaiHong KongAustin

Santiago

Berlin

JordanHondurasPanamaDominican RepublicThailand

Madrid

London

Calcutta

CharlotteSan Diego

South AfricaTurkey

Los Angeles

Venice

San Francisco

Since 2008, CEA has successful client engagements in 27 countries and has employees present in 8 countries

3

CEA’s service offerings are focused on three key areas, with a 8 year track record in over 8GW across a broad services portfolio in 27 countries

Supply Chain Management

• Technical Due Diligence (TDD)

• Owner’s engineering support

• On-site Quality Control Inspections

• Performance Analysis and Optimization

• Energy Yield Assessments

Engineering Services

• CEA’s Quality Assurance Program (CQAP) and Standards Implementation

• Bill-of-Materials (BOM) Analysis and Validation

• 24/7 Inline Production Quality Control• Container Loading Oversight• Comprehensive Factory Audits

Quality Assurance & Factory Audits

• Manufacturer Due Diligence

• Global Supplier Market Research

• Supply Chain Sourcing Optimization

• Supplier Management and Benchmarking

• Tactical and Operational Procurement

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Design

Phase 1Pre-productionQuality Control

Phase 4 – Downstream Support

Defining QA standards and requirements

Contract/projectset-up

Examination at job site (thermal imaging tests)

Third-party lab tests

Factory audits Production

monitoring

Construction

Phase 2Productionmonitoring

Module Inverters Racking Other BOS

Factory Level System Level

Commissioning

Module Inverters Racking OtherBOS

Phase 3Post-productionQuality Control

Module Inverters Racking Other BOS

System Design& Equipment Specs

Solar Output Analysis

Project & Construction Management

RFP deconstructand LCOE analysis

System commissioning support

Technical Troubleshooting

Independent Engineers (IE)

Technical Advisors in the past have overemphasized downstream quality without looking as closely on the product in more detail

Other third-party test labs

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CEA’s Quality Assurance Program (CQAP) prevents risk and ensures thatdownstream project stakeholders maximize the output of their system

Supplier’s certification

Product and factory certification liaising TUV,

SGS, UL, CE, etc. assessment centers

Bill of Materials (BOM)inspection data review

Input material monitoring

Production process control; monitoring of equipment

calibration, stringing, lay-out,lamination, curing and

framing

Production environmental control; monitoring ofinventory storage and

manufacturing workshop

ISO 2859 Sample rule

QCstandard

AQL rule

Product Inspection

Visualinspection

Functional test

IVtest

ELtest

Proper Packing

Container type

Container number

Seal number

Shipment plan

Content Listing

Packing list

Inspection certificate

Pre-ProductionProduction Monitoring Pre-Shipment Container Loading

6

Typical PV Module Production Process Flowchart: every step is a quality risk

1. Material Preparation

4. Backsheet Lay Up

3. String Interconnection

2. Cell Tabbing & Stringing

5. Lamination

6. Trimming7. EL Testing

8. Framing

9. Junction Box Installment

10. AB Glue Addition

1 2 2 4

5

78910

11

6

12 11.IV test

12. Packaging

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SummaryModule power decreased by 20W

Within 5 years, this rate may increase to 8-15W

EL testing utilizes special electromagnetic technologyto identify defects hidden from the naked eye.

Minor cracksThese minor cracks currently do not result in capacity loss – however, such cracks maydeepen or become “contagious” and affect nearby cells. In a worst case scenario, a cracklike this could lead to a loss of 1 W of capacity.

“Broken fingers”About 0.2 W loss

Long cracks across whole cellThese long cracks are slightly more severe and may result in slightly lower cell efficiencies.However, if such cracks deepen, a cell could potentially lose one-third of its capacity. Nearby cells affected may cause further losses in capacity. For each of these cells, we can expect a 1.2 W loss in capacity

Serious cracksThese are examples of the most serious types of cracks that a defective module may have, designated by the shaded areas. The size of the shaded areas typically corresponds to thedegree of capacity lost. These three cells with large crackscorrespond to approximately 4 W of capacity loss.

Source: CEA Internal Quality Control Findings

Common Production DefectsMicro crack caused risk is difficult to mitigate without the proper equipment (Electroluminescence – EL imaging) and the right standards, enforced by an independent and accredited QA third party

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SummaryThis cold soldering is caused by processinstability, and lack of training and proper qualitycontrol.

If these strings were to be laminated intothe module, this issue could elude detection,but will seriously deteriorate the performance ofsolar module over time.

High

Cells with cold soldering Seriousness Time Frame

Entire life of module

Points of non-contact on back of

cell stringing

Decreased power output

Cause Consequence

Cold soldering during cell stringing


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SummarySoldering residue between cells can act as an electrical conductor

This may lead to short circuiting amongstcells, a potential electrical safety risk Medium 5 Years

Seriousness Time Frame

Soldering residuebetween cells

Short circuiting, electrical fires

Cause Consequence

Poor handling duringsoldering process


Fire and Electrical Safety Risk

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SummaryHuman error during the layup orlamination process can lead to narrowgaps between cells.

Narrow cell spacing can lead to shortcircuiting amongst cells.

Medium

Fire and Electrical Safety RiskFrom Defective String Layup

10 Years


Insufficient spacebetween cells

Short circuiting between cells

Cause Consequence

Incorrect laminating,poor EVA material

In this examplecell spacing is less than the required 2mm

Source: CEA Internal Quality Control Findings11

SummaryHuman error committed during thesoldering process can lead to impropersealing of the junction box.

Insufficient sealing can lead to electrical fires as well.

Fire and Electrical Safety RiskFrom Junction Box Defects


Poor sealing ofjunction box

Self-ignition, electrical fires

Cause Consequence

Sloppy soldering

High 3 Years


SummaryDuring the backsheet measuring andcutting phase, workers must be careful toline up the backsheet with the edge of themodule, or else water leakage mayoccur., forcing module replacement.

High

Layup Defects

3-5 Years


Insufficientbacksheet length

Water leakage

Cause Consequence

Errors duringbacksheet cutting


CQAP has been performed in various facilities of Tier 1 manufacturers and the distribution of defect rates has showed surprising results.

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

18.0%

2012 2013 2014 2015 2016 2017

Def

ect

rate

s

2013 – 2016 YTD

Defect data from QA performed on over 100 projects totaling many GWs of modules

15 MW

30 MW

75 MW

100 MW

YTD TTTT

Projectsize

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Scattered defect distribution show that even on the same production lines as module assembly processes are not stable

CELL17%

BACKSHEET 13%

OTHER1%

EL69%

P R O J EC T 1

CELL36%

CELL STRING6%GLASS

10%BACKSHEET

7%

FRAME29%

JUNCTION BOX 5%

OTHER3%

EL4%

P R O J EC T 2

CELL16%

CELL STRING51%

GLASS6%

FRAME8%

OTHER11%

EL8%P R O J EC T 3

CELL28%

CELL STRING37%

GLASS6%

BACKSHEET6%

FRAME13%

EL10%

P R O J EC T 4

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Example of calculated NPVs for 2 100 MWp projects, produced with and without Quality Assurance program, using three scenarios

$25.4 M

$23.0 M$21.8 M

$20.6 M

$14.6 M

$12.5 M$11.5 M

$10.4 M

$ M

$5 M

$10 M

$15 M

$20 M

$25 M

$30 M

Projects withQuality Assurance(no excess loss)

Good scenario Medium scenario Bad scenario

Pro

ject

NP

V

Project A Project BProject size: 100 MW DC

Project A, fixed tiltPPA $80 MWHEPC cost: $95m

Project B, trackerPPA $60 MWH EPC cost: $107m

Projects without Quality Assurance

A BLending rate 6.00% 6.00%Equity 50.00% 50.00%Loan tenor 10 10O&M $1,000,000 $1,000,000 Land $500,000 $500,000 Inflation 2.50% 2.50%Tax rate 30.00% 30.00%PPA rate escalation 2.00% 2.00%Degradation of modules 0.65% 0.65%Energy yield per year MWh/MW 2,200 1,400PPA in $/MWh 60 80Pdc in MW 100 100Discount rate 5.00% 5.00%EPC cost $/Wdc 1.05 0.95Interconnection cost $1,805,000 $1,805,000

Quality Assurance done: NPV has its maximum value, as only standard warranted degradation (~0.7%/pa) is assumedGood scenario: manufacturer shows a small drop in quality w/o QA program (2 x 1% defect loss, or 2% in excess of warranty in project midlife)Medium scenario: manufacturer shows a medium drop in quality w/o QA program (3 x 1% defect loss, or 3% in excess of warranty in project midlife)Bad scenario: manufacturer shows a big drop in quality w/o QA program (4 x 1% defect loss, or 4% in excess of warranty in project midlife)

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NPV loss in $/W for the 2 projects, without applying Module Quality Assurance Programs, using three scenarios

$0.024

$0.037

$0.049

$0.021

$0.031

$0.041

$0.000

$0.010

$0.020

$0.030

$0.040

$0.050

$0.060

Good scenario Medium scenario Bad scenario

NP

V lo

ss in

$/

W

Project A Project B

Good scenario: manufacturer shows a small drop in quality w/o QA program (2 x 1% defect loss, or 2% in excess of warranty in project midlife)Medium scenario: manufacturer shows a medium drop in quality w/o QA program (3 x 1% defect loss, or 3% in excess of warranty in project midlife)Bad scenario: manufacturer shows a big drop in quality w/o QA program (4 x 1% defect loss, or 4% in excess of warranty in project midlife)

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The information herein has been prepared by CEA solely for the exclusive use of recipient. No representation,warranty or undertaking, express or implied, is made as to, and no reliance should be placed on, the fairness,accuracy, completeness or correctness of the information or the opinions contained herein. Neither CEA orany of its affiliates, advisors or representatives will be liable (in negligence or otherwise) for any losshowsoever arising from any use of this presentation.

Thank you for your attention

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