Ingen lysbildetittel

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Technology and raw materials for solar cell
quality quartz
Erik Larsen Knut L. SandvikDept. of geology
and mineral resources engineering,Norwegian
University of Science and Technology (NTNU),
7491 Trondheim, Norway
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Solar cell market
MWP
Year
Average growth rate in the solar electric energy
demand from 1990-2001 was 22 per year
Quartz demand2001 65 000 tons2010 350
000 tons
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Solar cell market
Thin film
Other
Multicrystalline
Monocrystalline
- Crystalline cells made from Si- Thin film
cells made from amorphous Si/CdTe/CuInGa
diselenide- Other cells electrochemical cells,
organic cells, etc..
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Crystalline silicon solar cell production
1) Mining and processing of raw materials (quartz
coke)2) Carbothermic reduction to
metallurgical-grade Si (MG-Si)3) Purification of
MG-Si to electronic-grade Si (EG-Si)4)
Production of silicon blocks from solar-grade Si
(SoG-Si)5) Wafer cutting and processing into
wafers
- Mainly quartzites and hydrothermal quartz-
Little processing other than size reduction-
Purity of quartz typical 97-98 SiO2
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Crystalline silicon solar cell production
1) Mining and processing of raw materials (quartz
coke)2) Carbothermic reduction to
metallurgical-grade Si (MG-Si)3) Purification of
MG-Si to electronic-grade Si (EG-Si)4)
Production of silicon blocks from solar-grade Si
(SoG-Si)5) Wafer cutting and processing into
wafers
Quartz Carbon
Carbothermic reduction
Refining
MG-Si
- Lump size material only (10-150 mm)- MG-Si
purity typical 98.5 Si
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Crystalline silicon solar cell production
1) Mining and processing of raw materials (quartz
coke)2) Carbothermic reduction to
metallurgical-grade Si (MG-Si)3) Purification of
MG-Si to electronic-grade Si (EG-Si)4)
Production of silicon blocks from solar-grade Si
(SoG-Si)5) Wafer cutting and processing into
wafers
MG-Si HCl
Trichlorosilane (HSiCl3)
Purification of HSiCl3
Deposition on Si rods
EG-Si
- Stream of by-products/waste- Highly energy
consuming- EG-Si purity ppb-ppt
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Crystalline silicon solar cell production
1) Mining and processing of raw materials (quartz
coke)2) Carbothermic reduction to
metallurgical-grade Si (MG-Si)3) Purification of
MG-Si to electronic-grade Si (EG-Si)4)
Production of silicon blocks from solar-grade Si
(SoG-Si)5) Wafer cutting and processing into
wafers
Growth (monocryst. Si)
EG-Si rejects processing losses(SoG-Si)
Si blocks
Casting (multicryst. Si)
- Highly energy consuming- Si purity ppm-ppb
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Crystalline silicon solar cell production
1) Mining and processing of raw materials (quartz
coke)2) Carbothermic reduction to
metallurgical-grade Si (MG-Si)3) Purification of
MG-Si to electronic-grade Si (EG-Si)4)
Production of silicon blocks from solar-grade Si
(SoG-Si)5) Wafer cutting and processing into
cells
Wafer cutting
Si blocks
Cell processing
Cut off
Sawing losses
To block prod.
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Purity and price of materials
1 ppt
50 - 60 /kg
EG-Si
1 ppb
200 - 230 /kg
Wafer
SoG-Si
1 ppm
25 - 30 /kg
0.1
1 - 1.5 /kg
0.05 /kg
MG-Si
1
Qtz
0.1
10
100
1000
/kg
1.0
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Crystalline Si cell production costs
- Processing of primary raw materials
approximately 0.5 of total costs
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Material impurities (ppm)
A - Good quality lump quartzB - Processed
hydrothermal quartzC - Processed pegmatite core
quartzD - Hydrochemically treated quartzMG -
Metallurgical gradeUMG - Upgraded metallurgical
gradeSoG - Solar grade
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Purity and price of quartz
SoG-Si
1 ppm
25 - 30 /kg
D
1.5 - 2.5 /kg
0.001
C
0.4 - 0.6 /kg
0.01
0.1
B
0.1 - 0.2 /kg
A - Lump qtz (mainly quartzites)B - Processed
qtz (normal pegmatite)C - Processed qtz
(pegmatite core)D - Hydrochemically treated qtz
1
A
0.05 /kg
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Current technology
Cell Module
Prod. of cells cell modules
Prod. of cells cell modules
Wafer
Prod. ofblocks
Wafer sawing
SoG-Si
Block
Prod. of EG-Si
EG-Si
Mining Processing
Lump quartz
Carbothermic reduction
MG-Si
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Current technology
Cell Module
Prod. of cells cell modules
Prod. of cells cell modules
- Over 50 of total costs- Very expencive
materials
Wafer
Prod. ofblocks
Wafer sawing
SoG-Si
Block
Prod. of EG-Si
EG-Si
Mining Processing
Lump quartz
Carbothermic reduction
MG-Si
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Current technology
Cell Module
Prod. of cells cell modules
Prod. of cells cell modules
- Almost 50 loss- Recycling required
Wafer
Prod. ofblocks
Wafer sawing
SoG-Si
Block
Prod. of EG-Si
EG-Si
Mining Processing
Lump quartz
Carbothermic reduction
MG-Si
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Current technology
Cell Module
Prod. of cells cell modules
Prod. of cells cell modules
- Approximately 30 of total costs - Highly
energy consuming
Wafer
Prod. ofblocks
Wafer sawing
SoG-Si
Block
Prod. of EG-Si
EG-Si
Mining Processing
Lump quartz
Carbothermic reduction
MG-Si
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Current technology
Cell Module
Prod. of cells cell modules
Prod. of cells cell modules
- Approximately 10 of total costs - Highly
energy consuming- Limited availability-
Unnecessary pure
Wafer
Prod. ofblocks
Wafer sawing
SoG-Si
Block
Prod. of EG-Si
EG-Si
Mining Processing
Lump quartz
Carbothermic reduction
MG-Si
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Current technology
Cell Module
Prod. of cells cell modules
Prod. of cells cell modules
- Approximately 3 of total costs- Impure raw
materials - Can not be refined to SoG-Si quality
Wafer
Prod. ofblocks
Wafer sawing
SoG-Si
Block
Prod. of EG-Si
EG-Si
Mining Processing
Lump quartz
Carbothermic reduction
MG-Si
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Current technology
Cell Module
Prod. of cells cell modules
Prod. of cells cell modules
- Less than 0.5 of total costs- Few high-grade
deposits - No processing due to requirements
Wafer
Prod. ofblocks
Wafer sawing
SoG-Si
Block
Prod. of EG-Si
EG-Si
Mining Processing
Lump quartz
Carbothermic reduction
MG-Si
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Future SoG-Si route
- Mineral processing- Electrolysis / plasma
metallurgy- Purification combined with
crystallisation
Cell Module
Prod. of cells cell modules
Prod. of cells cell modules
Wafer
Prod. ofblocks
Wafer sawing
SoG-Si
Block
Prod. of EG-Si
EG-Si
Electrolysis /plasma techn.
Quartz powder
Mining Processing
Mining Processing
Lump quartz
Carbothermic reduction
MG-Si
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Future SoG-Si route
- Mineral processing- Electrolysis / plasma
metallurgy- Purification combined with
crystallisation
Cell Module
Prod. of cells cell modules
Prod. of cells cell modules
Wafer
Wafer sawing
Prod. ofblocks
Block
SoG-Si
Processed quartz
Mining Processing
Electrolysis /plasma techn.
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Conclusion
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Conclusion
TODAY
FUTURE