Life after PERC and why bifacial PV will enter the US …isc-konstanz.de/fileadmin/deutsch/dokumente/Life_after...R. Kopecek, US DoE, September 13, 2018 History and future of PV, PERC,

Life after PERC and why bifacial PV will enter the US market quickly?

Dr. Radovan Kopecek and Dr. Joris Libal

R. Kopecek, US DoE, September 13, 2018

abstractPV (Photovoltaics) is becoming the cheapest energy source world wide- now in some parts even

dethroning coal energy as the most cost effective option. At the beginning of 2017, with a total installed

capacity of about 300GWp and lowest electricity prices between 2-3US$ct/kWh, PV has become visible

worldwide. End 2017 close to 100 GWp module installations have been added- EDF/Masdar delivered

the lowest bid ever of 1.78USct/kWh in Saudi Arabia with advanced bifacial module technology and

tracking. A new era of PV started- moving away from long time dominating Al-BSF solar cell.

PERC (Passivated Emitter and Rear Cell) technology is becoming faster than anybody would have

expected Nr. 1 technology in terms of production capacity. In 2018, with 75GWp capacity, PERC will

have more than 50% of the market share. However, not only that in some cases PERC modules are

degrading due to a novel degradation (LeTID) but also the reachable efficiencies are expected to come

to their limits. Then advanced n-type technologies will take over.

ISC Konstanz is, since its foundation 12 years ago, working on advanced n-type bifacial solar cell

concepts- mainly on nPERT (BiSoN) and IBC (ZEBRA). In this presentation we will show what will be

the next generation of solar cells after PERC took over the market. “Standard” 6 inch screen printed

nPERT and nIBC technologies are reaching efficiencies of 22% and 23% respectively. In order to reduce

costs and increase voltages new Al-metallisation technologies are entering the market. However, if

efficiencies >24% are targeted, low cost passivated contacts are required. With such technologies the

theoretical limit of c-Si technologies will be reached in couple of years in mass production. In order to

overcome this limit of ca. 28%, new technologies will be added to the c-Si devices: e.g. Perowskites on

top of bifacial passivated contact nPERT solar cells. Efficiencies of >30% are expected with LCOEs in

bifacial tracked PV systems below 1USct/kWh.


bifiPV2018 in Denver September 10/11

- 170 visitors

- R&D, industry and

financing sectorNREL, SANDIA, ASU,… sunpower,

sunpreme, prism solar, Soltec,

8minutenergy, …Black&Veatch, …

- common conclusion is that

after HSAT bifacial PV is

the next „big thing“ for

US PV market

- However still several

issues has to be

improved- mostly

improvement of

bankable simulations of

increased energy yield


bifiPV2018 in Denver September 10/11

- 170 visitors

- R&D, industry and

financing sectorNREL, SANDIA, ASU,… sunpower,

sunpreme, prism solar, Soltec,

8minutenergy, …Black&Veatch, …

- common conclusion is that

after HSAT bifacial PV is

the next „big thing“ for US

PV market

- However still several

issues has to be

improved- mostly

bankable simulations of

increased energy yield

R. Kopecek, US DoE, September 13, 2018 5

Bosch n-type technology

agenda

- ISC Konstanz

- PV until 2018

(life before PERC)

- PERC 2018

(life with PERC)

- What next?(life after PERC)

- Bifacial PV: the time has come

- Summary


ISC Konstanz Institute & technology transfer

2018


ISC Konstanz: who we are

7

International Solar Energy Research Center Konstanz

ISC Konstanz is a nonprofit organization based in Germany

and has been founded in 2005

its 50 scientists from over 20 different nations are focusing on

R&D on c-Si solar cells, modules and systems with academic and

industry partners in publicly funded as well as in bilateral projects

technology transfer of BiSoN (nPERT) and ZEBRA (IBC)


ISC Konstanz: technology transfer

8

2015: BiSoN (nPERT) transfer to industrial line at

MegaCell (Italy), production capacity 85 MW/year, cell

efficiency max. 21% achieved

2016: BiSoN R&D with Asian company

21.5+% average cell efficiency achieved in pilot line

2017: BiSoN transfer to industrial line at adani (India)

started - production capacity: 100 MW/year

NEW: 2019: ZEBRA (IBC) transfers in EU and Asia



BiSoN (nPERT) and ZEBRA (IBC)

21.5+% 23.0+%very low COO due to BSG passivation and standard low cost processes


Bosch n-type technologyISC´s roadmap for screen printed

6” Si solar cells 2018

>20%

>21%

>22% stable >22% stable

>23.5% stable

BiSoN

ZEBRA

MoSoN

PELICAN19.5%

21.5% 21.5%

23.0%

21.0%

laser

SiO2/SiNx

(or Al2O3/SiNx)

B-diffusion

(B-passivation)

n-type waferp+ Ag(Al) paste

fast laser

SiNx



n-type low cost c-Si solar cells 2018

21.8%21.5% 22.5%

BiSoN MoSoN ZEBRA

21.5%+ 22%+ 23%+

Voc= 670mV Voc= 690mV Voc= 685mV

Bifi: 90+% Bifi: 70+% Bifi: 80+%

Implemented in industry almost ready for industry ready for transfer to industry

Instead of AlOx,all these n-type technologies use BSG- (boron silicate glass),formed during LP-BBr3 diffusion, as low-cost passivation layer


Prof. Dr. Ernst Bucher

ISC Konstanz: sponsors and members


ISC partners/customers

universities/institutes

machine builders component suppliers

cells/modules and systems


ISC team

14


ISC Konstanz: international team

15

20 nations: almost every 2nd employee is from abroad

50 people involved in R&D of c-Si PVGermany (30),

Romania (3),

Italy (2),

Algeria (1),

Austria (1),

Cameroon (1),

Chile (1),

China (1)

Czech Republic (1),

Hungary (1),

India (3),

Kazakhstan (1),

Poland (1),

Peru (1)

Switzerland (1),

Taiwan (1),

Turkey (2),

Ukraine (1),

Venezuela (1)


ISC departments/groups

16


MegaCell

40MW/a BiSoN in Q2 2015 >>> 80MW/a BiSoN in Q4 2015

2015: 21% BiSoN cell at MegaCell


AtaMo 2018

BiSoN 2015

BiSoN 2017

All technology transfers of ISC Konstanz

ZEBRA 2018

BiSoN 2017

BiSoN/ZEBRA 2019


2017/2018

BiSoN technology transfer


BiSoN technology transfer


2018-2019

ZEBRA technology transfer


monofacial ZEBRA (IBC) module

315+Wp

no LID

no LeTID

no PID

If bifacial:

400+Wpe


Bifacial ZEBRA module at SNEC

HHSD (SPIC) the largest renewable energy electricity provider in China

is interested in bifacial ZEBRA (with HSAT)


ZEBRA for BIPV and PIPV

Severa

l colla

bora

tions w

ith U

S c

om

panie

s

and u

niv

ers

itie

s


ISC Konstanz and Chile

- 2007: Prof. Bucher traveled Chile to promote renewables

- 2008: First PhD Student from Chile at ISC Konstanz (in total 5 PhD

students from Chile) More to come.

- 2012: ISC Konstanz starts bifacial workshops (this year in US)

- 2012: ISC Konstanz visited Chile (SERC)

- 2013: SolarChilD project starts (BMBF): development of AtaMo

- 2014: bifacial workshop in Chile (Antofagasta)

- 2015: First discussions about AtaMoS-TeC with CORFO and SERC

- 2016: Proposal to CORFO to fund AtaMoS-TeC

- 2017: Open tender from CORFO

- 2018: AtaMoS-TeC starts

>> many countries are showing interest for XMoS-TeC (Peru, Ethiopia,

Burkina Faso, Nigeria…)


ISC Konstanz and Chile


AtaMoS-TeC

AtaMoS-TeC: bifacial technology center

12MioUS$ (CORFO) + 5MioUS$ (Industry) for 5 years


development cooperation 2018

28


Development- and Education-cooperation

Module DonationsEducation ISC´s PV-Projects


development cooperation


development cooperation: GhanSol

31

Nyakrom

school


PV cell technologies until 2018


100GWp installed in 2017

ca. 50% in China

Accumulated PV systems end 2017 at 400GWp

>> 1TW installed in 2022

PERC in production with 30GWp approaching 22%

Expected: 60-70GWp in 2018

(but: LeTID could be a challenge)

Module prices at 30-40USct/Wp (now even below 30USct/Wp)

Lowest bid from EDF/Masdar in Saudi Arabia of

1.79USct/kWh (bifacial HSAT)

Important numbers for PV 2017/2018


First they ignore you then they laugh at you

then they fight you and then you win.

History, status and future of PV


Kopecek et al., PV international, issue 21, 2013 (updated for bifacial book)

History, status and future of PV


History and future of PV, PERC, bifi

2000 2003 2006 2009 2012 2015 2018 2021 2024 2027

0% 0% 0% 0% 0.1% 0.5% 1-2% 4% 6% 8%

First they ignore you then they laugh at you then they fight you and then you win.

PV against other energy sources (total installations)



2000 2003 2006 2009 2012 2015 2018 2021 2024 2027

0% 0% 0% 0% 0.1% 0.5% 1-2% 4% 6% 8%



0% 0% 0% 0% 0% 5% 50% 70% 100% 100%


PERC against Al-BSF (market share)



2000 2003 2006 2009 2012 2015 2018 2021 2024 2027

0% 0% 0% 0% 0.1% 0.5% 1-2% 4% 6% 8%



0% 0% 0% 0% 0% 5% 50% 70% 100% 100%


PERC against Al-BSF (market share)

0% 0% 0% 0% 0% 0.1% 0.3% 5% 10% 40%

Bifacial against monofacial (total installations)



0 100 200 300 400 500

Moduleprice per area [$/m2]

50

40

30

20

10

0

G1

G3sc-Si (n-type)

mc-Si (p-type)

CdTe

2009

Effi

cien

cy[%

]

sc-Si (p-type)

G2

Kopecek & Libal, PVTech,27 May 2015, 17 July 2015Limit for industrial c-Si solar cells reached in 2030: what next?

Technology forecast 2018-2030


0 100 200 300 400 500


50

40

30

20

10

0

G1

G2

G3sc-Si (n-type)

mc-Si (p-type)CdTe

III-V MJ

20132009Ef

fici

ency

[%]

sc-Si (p-type)


2017

2017

2017



0 100 200 300 400 500


50

40

30

20

10

0

G1

G2

G3sc-Si (n-type)

mc-Si (p-type)CdTe

III-V MJ

20132009Ef

fici

ency

[%]

sc-Si (p-type)


20172017

BIFACIAL2017



0 100 200 300 400 500


50

40

30

20

10

0

G1

G2

G3sc-Si (n-type)

mc-Si (p-type)CdTe

III-V MJ

20132009Ef

fici

ency

[%]

sc-Si (p-type)


20172017

2017



0 100 200 300 400 500


50

40

30

20

10

0

G1

G2

G3sc-Si (n-type)

mc-Si (p-type)CdTe

III-V MJ

20132009Ef

fici

ency

[%]

sc-Si (p-type)


20172017

G3NEW

2030 2017



0 100 200 300 400 500


50

40

30

20

10

0

G1

G2

G3sc-Si (n-type)

mc-Si (p-type)CdTe

III-V MJ

20132009Ef

fici

ency

[%]

sc-Si (p-type)


20172017

G3NEW

2030 2017

BIFACIAL



0 100 200 300 400 500


50

40

30

20

10

0

G1

G2

G3sc-Si (n-type)

mc-Si (p-type)CdTe

III-V MJ

20132009Ef

fici

ency

[%]

sc-Si (p-type)


20172017

G3NEW

2030

TANDEM

Up-down conversion/shifting

2017



ITRPV forecast


ITRPV forecast

Al-BSF

HJT

IBC

Tandem

PERL

PERT

PERC


ITRPV forecast

Al-BSF

HJT

IBC

Tandem

PERL

PERT

PERC


PV TECH forecast


PV TECH forecast


PV cell TECH 2018


Lowest cost

High efficiency

Low cost

Highest efficiencyIBC mono

PERC mono

Al-BSF mono

Al-BSF mc

- mc-Si solar cells and modules are still most

cost effective (costs/Wp)

- advanced c-Si concepts have lowest LCOEs

in systems

COO vs LCOE


PV cell TECH 2018


PERC



Al-BSF vs. PERC

20%

22%



Bifacial PERC

21.5%



monofacial PERC record cell in March 2018



monofacial PERC record cell in May 2018

23.95%



monofacial PERC (real efficiencies)

- Averages in production: 21.5%-21.7%

- Efficiencies in R&D: 22+%

- JinKo´s largest 1.17GW PV installation in Abu

Dhabi with PERC at 2.42USct/kWh in 2019



monofacial PERC (real efficiencies)

- Averages in production: 21.5%-21.7%

- Efficiencies in R&D: 22+%

- JinKo´s largest 1.17GW PV installation in Abu

Dhabi with PERC at 2.42USct/kWh in 2019


What next?(life after PERC)



nPERT vs. IBC

23%

22%


Technologies to come after PERC

63

Short term (next 2 to 3 years)

nPERT B-diffusions (LPCVD BBr3, APCVD with BSG passivation, …)

Al contacting and selective emitter technology for nPERT and IBC

IBC with low cost processes for 23% - 24% efficiency

Medium term (next 3 to 5 years)

Further efficiency step (25%+) by passivated contacts for nPERT and IBC

Heterojunction : both sided contacted and back contact (IBC)

Long term (more than 5 years from now)

“peroPERT”

c-Si/perovskite tandem cells: perovskite cell on top of nPERT in order to

overcome the efficiency limitation of c-Si PV cells of 29.4%



n-type low cost c-Si solar cells 2018

21.8%21.5% 22.5%

BiSoN MoSoN ZEBRA

21.5%+ 22%+ 23%+

Voc= 670mV Voc= 690mV Voc= 685mV

Bifi: 90+% Bifi: 70+% Bifi: 80+%

Implemented in industry almost ready for industry ready for transfer to industry

Instead of AlOx,all these n-type technologies use BSG- (boron silicate glass),formed during LP-BBr3 diffusion, as low-cost passivation layer


Factory layout mc-Si Al-BSF


Factory layout Cz-Si PERC


Factory layout Cz-Si nPERT (BiSoN)


Factory layout Cz-Si IBC (ZEBRA)


Cz-Si wafer price history (pvinsights.com)

Current price gap between n-type and p-type: + 5%

+ 33%

+ 5%


2002

advantage weight

p- vs. n-type c-Si cells

Sunpower

Sanyo


2004

advantage weight



2007

advantage weight



2010

advantage weight



2011

advantage weight


Sunpower

Panasonic

Yingli

LG elect.

BOSCH

Suniva

Silevo

Sunpreme

Later also

Misson

Solar


2013

advantage weight



2016

advantage weight



2017

advantage weight



2018

advantage weight



COO, LCOE


Cell and module CoO (06/2018)

Assumption: vertically integrated cell & module manufacturer in Asia ( 1GW/year)

0.30 0.30 0.31 0.33


LCOE: assumptions

- monofacial energy yield: 1930 kWh/kWp/year (MENA)

- system lifetime: 25 years

- discount rate: 6%

- bifacial factor nPERT: 90%, bifacial factor PERC and ZEBRA: 75%

- system cost (including module cost as shown above):

- monofacial PERC fixed tilt: 0.71 USD/Wp

- monofacial PERC HSAT: 0.83 USD/Wp

- tracking gain: 16%

- combined gain (tracking + bifacial): 33% for PERT, 30% for PERC and

ZEBRA


LCOE: results


summary 1

- since mid 2016 (when mono c-Si wafer prices approached mc-Si) China is

pushing innovations into the market

- PERC is a success story and PERC+ is coming: in 2017 around

30 GW production capacity; end 2018 50 GW are expected

- new n-type players are entering the market: at the moment 10GW capacity

(mainly nPERT with a small part of IBC)

- CoO of nPERT is approaching PERC

(and n-type and p-type wafer prices almost reached parity)

- low cost IBC-cells (bifacial and monofacial) are ready to enter the market

- LCOE of bifacial PERC+ and nPERT systems can be around 20% lower

than for standard monofacial fixed tilt

- bifacial PERC+ and nPERT will become dominant cell technologies in the

near future; maybe also HJT will be more visible

BUT: WE HAVE TO BE CAREFULL BECAUSE OF LeTID


Bifacial PV technology


Bifacial PV systems: best reported

1.25 MWp


Bifacial PV systems: best reported

19-20% bifacial

energy gain

1.25 MWp


Bifacial PV systems: mostly shown

20+% bifacial

energy gain2.5 MWp


Bifacial PV systems: largest fixed tilt

ca. 12% bifacial

energy gain

50 MWp

100 MWp


Bifacial PV systems: largest rooftop

10 MWp


Bifacial PV systems: largest tracked

71 MWp


Bifacial PV systems: largest vertical

2 MWp


Bifacial PV systems: largest vertical

2 MWp

10+% bifacial

energy gain


Bifacial applications (from LinkedIn)








Prognoses of bifacial market share


Bifacial book


Bifacial book


Bifacial history

Bifacial book 2018


Bifacial history

Bifacial book 2018


Bifacial history

Bifacial book 2018


Why will bifacial win?

Bifacial book 2018


Possible cell technologies

Bifacial book 2018


Bifacial gain for fixed tilt

Bifacial book 2018


Bifacial gain

HJT: b>92

PERT: b>90

PERC: b>80

IBC: b>70

Dark soil: a>10%

Grass: a>15%

Sand: a>30%

White roof: a>70%

1 sun 1 sun

Module

Ground


Bifacial gain

HJT: b>92

PERT: b>90

PERC: b>80

IBC: b>70

Dark soil: a>10%

Grass: a>15%

Sand: a>30%

White roof: a>70%

1 sun 1 sun

80 cm

BG: 7±3%

Module

Ground

Construction: fixed tilt


Bifacial gain

HJT: b>92

PERT: b>90

PERC: b>80

IBC: b>70

Dark soil: a>10%

Grass: a>15%

Sand: a>30%

White roof: a>70%

1 sun 1 sun

80 cm

BG: 10±3%

Module

Ground



Bifacial gain

HJT: b>92

PERT: b>90

PERC: b>80

IBC: b>70

Dark soil: a>10%

Grass: a>15%

Sand: a>30%

White roof: a>70%

1 sun 1 sun

80 cm

BG: 15±3%

Module

Ground



Bifacial gain

HJT: b>92

PERT: b>90

PERC: b>80

IBC: b>70

Dark soil: a>10%

Grass: a>15%

Sand: a>30%

White roof: a>70%

1 sun 1 sun

80 cm

BG: 25±3%

Module

Ground



Bifacial gain

HJT: b>92

PERT: b>90

PERC: b>80

IBC: b>70

Dark soil: a>10%

Grass: a>15%

Sand: a>30%

White roof: a>70%

1 sun 1 sun

80 cm

BG: 5±3%

Module

Ground

Construction: HSAT


Bifacial gain

HJT: b>92

PERT: b>90

PERC: b>80

IBC: b>70

Dark soil: a>10%

Grass: a>15%

Sand: a>30%

White roof: a>70%

1 sun 1 sun

80 cm

BG: 8±3%

Module

Ground

Construction: HSAT


Bifacial gain

HJT: b>92

PERT: b>90

PERC: b>80

IBC: b>70

Dark soil: a>10%

Grass: a>20%

Sand: a>30%

White roof: a>70%

1 sun 1 sun

80 cm

BG: 10±3%

Module

Ground

Construction: HSAT


Bifacial gain

HJT: b>92

PERT: b>90

PERC: b>80

IBC: b>70

Dark soil: a>10%

Grass: a>15%

Sand: a>30%

White roof: a>70%

1 sun 1 sun

80 cm

BG: 20±3%

Module

Ground

Construction: HSAT


Bifacial modules

115


116

Bifacial module technologies

Junction box

Backsheet Glass

Encapsula

nt

FrameComponents

72 Solar cells



Standard moduleF

ront sid

e

Rear

sid

e

72 Solar cells



Standard moduleF

ront sid

e

Rear

sid

e

Encapsulant



Standard moduleF

ront sid

e

Rear

sid

e

Backsheet



Standard moduleF

ront sid

e

Rear

sid

e

Glass



Standard moduleF

ront sid

e

Rear

sid

e

Frame



Standard moduleF

ront sid

e

Rear

sid

e

Junction box



Bifacial module first generationF

ront sid

e

Rear

sid

e



Bifacial module frameless

Rear

sid

e

Fro

nt sid

e



Rear

sid

e

Fro

nt sid

e

Bifacial module frameless, shallow junction box



Rear

sid

e

Fro

nt sid

e

Bifacial module frameless, shallow junction box and half cells



Bifacial module: properties - frameless

(or with frame)

- double glass

(or transparent backsheet)

- shallow junction box

(or more boxes)

- Polyolefin

(or EVA)

- n-type solar cells

(or p-type)

- 5 BB solar cells

(or multi BB, or shingling)

- half cells

(or full cells)



Bifacial module: properties - frameless

(or with frame)

- double glass

(or transparent backsheet)

- shallow junction box

(or more boxes)

- Polyolefin

(or EVA)

- n-type solar cells

(or p-type)

- 5 BB solar cells

(or multi BB, or shingling)

- half cells

(or full cells)


Bifacial module technologies: standard

R. Kopecek et al., PVI37,

September 2017

Possible measurements

Standards: to come in

January 2019


electricity costs from PV (utility scale)

25 ct/kWh

3.5ct/kWh3ct/kWh

8 ct/kWh

2010 2012 2014 2016 2018 2020 2022

13 ct/kWh

5 ct/kWh4ct/kWh

for 1500-2000 kWh/kWp


electricity costs from PV (utility scale)

25 ct/kWh

3.5ct/kWh3ct/kWh

8 ct/kWh

2010 2012 2014 2016 2018 2020 2022

13 ct/kWh

5 ct/kWh4ct/kWh

Bifacial tracking

for 1500-2000 kWh/kWp


summary 2

132

- c-Si solar cells in future will be bifacial anyhow

- many companies are already producing bifacial cells:

PERC+, nPERT, HJT and soon IBC

- PERC will become Nr.1 technology in 2018/2019

- many modules in future will be double glass based anyhow

- the system kWh can be extremely increased by using bifacial

modules and/or simple tracking in addition

- in total >1GWp large bifacial systems are already installed

>> EVAUATION OF EXISTINING SIMULATION PROGRAMS

ARE NEEDED TO MAKE BIFACIALITY MORE BANKABLE


Largest boom: HSAT bifacial systems

Just like HSAT few years back bifaciality will enter the

US PV market with a high impact from 2020 on

(after the financing sector gained more confidence)

Let us move together to costs below

1USct/kWh

Documents

Life after PERC and why bifacial PV will enter the US …isc-konstanz.de/fileadmin/deutsch/dokumente/Life_after...R. Kopecek, US DoE, September 13, 2018 History and future of PV, PERC,