Presentation KAUST distribution

KAUST Solar Future
Nov. 2015 B. Ceccaroli
MARCHE AS 1
SILICON FEEDSTOCK:
silicon processes and
products for solar industry
Bruno Ceccaroli

90% of PV-systems are built on crystalline silicon
2
Fraunhofer Institute for Solar
Energy Systems ISE:
Photovoltaics Report
Freiburg, 24 October 2014
KAUST Solar Future
MARCHE AS

Outline
• Solar cell materials and their availability
• Metallurgical grade silicon (MGS): Manufacture, applications,
cost and price
• Solar grade silicon (SGS): Processes, products
• Product differentiation: by shape, purity and cost
• SGS industry trends: supply-demand
• Conclusion
KAUST Solar Future
MARCHE AS 3

SECTION 1
Solar cell materials and their availability
KAUST Solar Future
MARCHE AS 4

KAUST Solar Future
MARCHE AS 5
About Silicon
The EARTHS crust
consists of 27% Silicon
• Occurs in nature in tretavalent state, as
silicate and silica.
• Natural element, 27% of the earth crust,
second largest element after oxygen
•Identified in 1810 by Berzelius (Gay-
Lussac, Thénard)
• First produced by Sainte-Claire Deville
(1853) by electrolysis of an
aluminosilicate melt
•Industrially metallurgical grade silicon
(99,9%) may be produced in millions of
tonnes

KAUST Solar Future
MARCHE AS 6
Fortunately Silicon is an Abundant Natural
Resource
0.001
0.01
0.1
1
10
100
1000
10000
100000
1000000
0.00001 0.0001 0.001 0.01 0.1 1 10 100 1000 10000 100000 1000000
Ru
Pt Te
In
SeAu
Ag Cd
Cu
Zn
Ni
Pb
Fe
REE
Si
Al
V
Co
Li
Ga
Ge
World primary
refinery production
(g/capita/yr)
Average abundance in the continental crust (ppm)
Rare, scattered and
minor metals
Courtesy of B. Andersson Sandén

SECTION 2
Metallurgical grade silicon (MGS):
manufacture, applications, cost and price
KAUST Solar Future
MARCHE AS 7

KAUST Solar Future
MARCHE AS 8
Manufacturing Metallurgical Grade
Silicon (MGS)
Courtesy of Silicium Bécancour

KAUST Solar Future
MARCHE AS 9
Metallurgical grade silicon
MGS has been produced in
large electrical arc furnaces
since 1905.
Source: A. Schei et al. ELKEM
SiO2 + C = Si + 2 CO

Manufacturing Metallurgical grade Silicon
(MGS)
Si (Silicon)SiO2 (Quartz)
+ =
C (Carbon) and Power
SiO2 + 2C = Si + 2 CO
KAUST Solar Future
MARCHE AS 10
Courtesy
Prof. Gabriella Tranell

MGS Commercial Usage
11
Aluminum Alloys Polysilicon to electronics Silicones Photovoltaics
Byproduct:
Silica fume
Courtesy Jan Ove Odden

MGS Market Segments
Total market 2015: 2,5 million
metric tons
KAUST Solar Future
MARCHE AS 12
Courtesy Prof. G. Tranell

According to CRU Global solicon demand will
continue to grow at 5,9%
KAUST Solar Future
MARCHE AS 13

Current silicon production is relatively
concentrated in China, USA/Canada, Norway,
EU(France/Spain), Brazil
China has increased its share to 65-70%
between 2010 and 2015:
Domestic consumption is increasing on
expense of export
New comers:
Iceland, Middle East, Malysia
Plant locations determined by:
(Historical) cost conditions:
Access to inexpensive electricity
Fiscal, trade and environmental policies and
regulations
China
57 %
EU
8 %
USA
7 %
CIS
3 %
RoW
8 %
Brazil
10 %
Norway
7 %
Silicon production by country/region 2011
Data: CRU
KAUST Solar Future
MARCHE AS 14

15
Major price change after 2008
Price range EU-US: 1-2 $/t before 2008; 2,5-3,5 $/t after 2008

SECTION 3
Solar grade silicon (SGS):
Processes, products
KAUST Solar Future
MARCHE AS 16

SGS specifications – SEMI Standard: ppm and
ppb level needed vs. % level in MGS
KAUST Solar Future
MARCHE AS 17
category units I II III IV
Acceptor
(B, Al)
Donor
P, As,Sb
Carbon C
Transition
Metals
Alkali(alkal
i earth
metals
ppba
ppba
ppma
ppba
ppba
<1
<1
<0,3
<10
<10
<20
<20
<2
<50
<50
<300
<50
<5
<100
<100
<1000
<720
<100
<200
<4000

KAUST Solar Future
MARCHE AS 18
MGS is not pure enough to produce solar cells:
further refining is needed
Chemical composition of commercial MG silicon
Quality of the produced MG-Si is a
function of the raw materials used
in the production
Source: A. Schei et al. ELKEM

Chemical vs. metallurgical route
• Developing industrial large scale and cost efficient processes
to solar grade silicon remains a high priority
• There are two main avenues:
– Metallurgical route: purification of elementary silicon in the liquid
or solid phase
– Chemical route: purification by fractional distillation/condensation
of a volatile silicon bearing compound
KAUST Solar Future Nov.
2015 B. Ceccaroli
MARCHE AS 19

KAUST Solar Future
MARCHE AS 20
Silane plant at REC Silicon
Moses Lake (WA) and Butte (MT)
The chemical route has been the
traditional approach to purify silicon for
solar cells

Trichlorosilane and monosilane are the only
volatile compounds commercially used to
produce polysilicon
• Established process, current market leader
• Generate by-products containing chlorine
SiHCl3 + H2  Si + 3HCl
SiH4  Si + 2H2
• Hydrogen is the only chemical by-product
• Homogeneous decomposition of silane generates silicon powder
21
KAUST Solar Future
MARCHE AS

Two silicon volatile melecules, two types of
reactor Three well proven commercial
processes
2015 B. Ceccaroli
MARCHE AS 22
TCS
(SiHCl3)
Silane
(SiH4)
Siemens
hot
filament-
rod
X X
Fluidized
Bed
Reactor
X

“Siemens” Process
• ”Bell jar” reactor
• Silicon filaments or slim rods made
in specific/separate growth process
(e.g. FZ)
• Filament connected to electrical
graphite conductors
• 2 power input systems and
preheating of the filament
• Increasing power input and gas
adjustment along the growth
• Massive heat loss through cooling
of reactor wall
• Gas silicon precursor: SiHCl3 or
SiH4
• Batch/cycle time: 60-150 hr
• Post-deposition process:
harvesting, crushing
KAUST Solar Future Nov. 2015
B. Ceccaroli
MARCHE AS 23
Courtesy of REC Silicon

Fluidized Bed Reactor
• Ascending flowing gas
percolates through the particle
bed
• At a certain flow rate particles
begin to lift making the bed
behave like a fluid
• Large degree of temperature
uniformity  uniform CVD
• Control parameters: particle
density, size distribution, bed
heigth, gas flow, pressure
• As particles grow, the heaviest
particles need to be removed
and replaced by smaller ones
(”seeds”) to keep the bed under
steady state
KAUST Solar Future Nov. 2015
B. Ceccaroli
MARCHE AS 24
Silicon Return
Exhaust H2,unreacted
silane and elutriated fine
nano-silicon
Heated
H2
Silane
Silicon
granules
X
X

Metallurgical purification of silicon –
upgraded MGS
• Raw material selection
• Carbothermal reduction
• Metallothermal reduction
• Two or three phase purification system involving molten
(liquid) silicon (pyrometallurgical processes in ladle or
reactor)
• Liquid-Liquid (solid) extraction: Slag treatment
• Liquid- Gas extraction: Gas treatment.
• Two phase purification involving solid state silicon
• Leaching (hydrometallurgical processes, low
temperature)
• Alloying (pyrometallurgical processes, high temp.)
• Solid state refining
• Crushing
• Classifying (dry or wet)
• Phase transfer
• Crystallization
• Zone refining
• Electrolytic transport
25
KAUST Solar Future
MARCHE AS 25

Comparison by output: TCS/Siemens by far the dominant
technology; silane/FBR may be ~20% of total capacity by
2018; UMG remains marginal (5%?)
26
Gøran Bye | ©AMMS | Polysilicon Market Update | 16 March 2015
-
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
450,000
2012 2013 2014 2015 2016 2017 2018
MTperYear
Taking existing capacity - operating and idled - and known ongoing expansion
initiatives into account, TCS/Siemens will still be the dominant technology in
2018, but Silane/FBR is posed to double its share of the market
(REC/GCL/SUNE volumes @ face value)
Silane/FBR (MT/y)
TCS/Siemens (MT/y)
Sources: AMMS estimate based on industry and company announcements and analyses
KAUST Solar Future
MARCHE AS

SECTION 4
Product differentiation: by shape, purity and cost
KAUST Solar Future
MARCHE AS 27

2015 B. Ceccaroli
MARCHE AS 28
Silicon products from “Siemens”
Reactors

Silicon products from FBR
2015 B. Ceccaroli
MARCHE AS 29
Silicon Return
Exhaust H2,unreacted
silane and elutriated
fine nano-silicon
Heated
H2
Silane
Silicon
granules
X
X

Silicon products from metallurgical routes –
may take various shapes
30
• Flexible form factors
• Dependent on last step in
purification process and
customers’ requirements
• Lumps
• 5mm – 200mm pieces
• Granules/chips
• 0.5mm – 10mm
• Bricks
• Sawn from ingots
• Different sizes
KAUST Solar Future
MARCHE AS

Differentiation by purity
Impurity
Siemens (Solar)
(value range)
FBR
(value range)
U-MGS
(value range)
P (donor)
B (acceptor)
Total metals
C
O
Gas inclusion
0.3-5 ppba
0.1-5 ppba
20-50 ppbw
0.25-1 ppma
0.5-5 ppmw
0.3-20 ppba
0.3-20 ppba
30-1,000 ppbw
0.5-10 ppma
10-100 ppmw
H2
300-1,000 ppba
500-2,000 ppba
100-1,000 ppbw
50-200 ppma
(100 ppmw)
• Higher Metal concentration  affects life time minority charge carriers lower cell
efficiency
• Oxygen form pair with B  affects Light Induced Degradation (LID)
• Oxygen, Carbon, metals form inclusions which may destroy single crystal structure
(CZ)
• High dopant (B, P) concentration  compensation reduced material yield  risk of
LID  risk of reverse current breakdown
31
KAUST Solar Future
MARCHE AS

Side by side – total energy consumption
32
• Solar grade silicon manufacturing consumes
large amounts of energy that negatively
impacts both silicon economics, energy pay-
back time and carbon emissions of PV
• Focusing on the power consumption only
will omit the significant need for thermal
energy that is delivered by burning natural
gas, diesel, or coal
• In many geographies the access to, and the
pollution from, power generation and
feedstock for thermal energy is
unsustainable and costly
KAUST Solar Future
MARCHE AS

Side by side – what really matters is total cost
33
Best InClass
TCS/Siemens HC,
existing/
debottlenecked
TCS/Siemens HC
greenfield, PRC ?
Best InClass
uMGSexisting
Most advanced
uMGS greenfield,
PRC ?
Best InClass
SiH4/FBR already
existing
SiH4/FBR
greenfield, PRC ?
-
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
CapitalExpenditureperKilogramCapacity(USD)
Variable cash cost of production, finance cost & maintenance;but excluding SG&A
(USD/Kg)
USD 27.50 per Kilogram
Cost lines assume:
10 years' straight line depreciation; maintenance expense = 4% of initial capex; financial cost = 4% of 50% of capex
Sources: Industry announcements; REC presentation dated May 17, 2012; Elkem Solar; AMMS estimates
KAUST Solar Future
MARCHE AS

SECTION 5
SGS industry trends: supply-demand
KAUST Solar Future
MARCHE AS 34

The polysilicon industry is indeed (re-)consolidating: three
capacity tiers emerge towards 2018
35
-
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
2012 2013 2014 2015 2016 2017 2018
MTperYear
From
"Big Four" & "Next Six"
to
"Big Two", "Medium Three"
& "Next Five" ?
"Others"
TBEA Xinte Silicon
DAQO New Energy
LDK Silicon
SunEdison
Tokuyama
Hemlock Semiconductor
REC Silicon
OCI Company
Wacker Chemie
GCL Poly
Sources: AMMS estimate based on industry and company announcements and analyses
KAUST Solar Future
MARCHE AS

Supply/demand balance in 2014–16 (US$ 5.5-7bn global
market); net new capacity needed from 2017 and onwards
36
Gøran Bye | ©AMMS | Polysilicon Market Update | 16 March 2015
KAUST Solar Future
MARCHE AS

2015 B. Ceccaroli
MARCHE AS 37
Final remarks, conclusion
• Crystalline silicon remains the dominant PV technology
• Solar grade silicon is fragmented in at least three categories of
products: Siemens polysilicon, FBR polysilicon and UMG silicon.
• Although more expensive and energy consumming Siemens
polysilicon is by far the main feedstock. FBR is increasing, UMG
silicon exhibits a great potential but remains marginal
• SG silicon’s offer is currently exceeding the demand resulting in low
prices. But continued growth of PV calls for more capacity from 2017
and onwards
• SG silicon is capital and energy consumming offering reward
opportunities for those affording both capital and cheap energy
• MG Silicon is the raw material common for all solar grade silicon (one
exception). It is also capital and energy consumming. It’s a not
replaceable raw material not only for PV and semiconductors but also
for aluminum alloys and silicones. With current pricing MGS offers
good return on invested capital and should be considered as
investment target.

2015 B. Ceccaroli
MARCHE AS 38
For more details consult
• Handbook of Photovoltaic Science and
Engineering
Edited by ANTONIO LUQUE, IES, University
of Madrid and STEVEN HEGEDUS, University
of Delaware, USA. John Wiley & Sons Ltd,
2003
2nd edition, 2011, Chapter 5: Solar Grade
Silicon Feedstock by Bruno Ceccaroli & Otto
Lohne
• Gøran Bye and Bruno Ceccaroli,
Solar Grade Silicon: Technology Status and
Industry Trends, presented at Silicon Materials
Workshop, Rome, Oct. 7-8, 2013; published in
Solar Energy Material & Solar Cells (Elsevier,
2014) pp. 634-646.

THANK YOU FOR YOUR ATTENTION
Particular thanks to Göran Bye, Alan Crawford,
Jorn De Linde (CRU), Gabriella Tranell (NTNU), Jan
Ove Odden (Elkem) for invaluable advice and
sharing information.
KAUST Solar Future
MARCHE AS 39

Presentation KAUST distribution

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Presentation KAUST distribution

Similar to Presentation KAUST distribution (20)

Presentation KAUST distribution