Impact of Materials Prices on Cost of PV Manufacture Part I (Crystalline Silicon)

Size: px

Start display at page:

Download "Impact of Materials Prices on Cost of PV Manufacture Part I (Crystalline Silicon)"

Melissa Mosley
7 years ago
Views:

1 Impact of Materials Prices on Cost of PV Manufacture Part I (Crystalline Silicon) Nigel Mason SMEET II Workshop, London 27 Feb 2013

2 content Brief introduction to Solar PV Technologies Part I - Crystalline Silicon Case Study 1 - Silicon Silicon production, consumption, price, cost reduction and impact Case Study 2 - Silver Usage in PV, silver demand & price, alternative technology Part 2 - Thin Film to be resented by Chiara Candelise Conclusions 2

reduction and impact Case Study 2 - Silver Usage in PV, silver demand & price,

3 technology platforms flat-plate sun-tracking concentrator Crystalline Silicon Thin Film Emerging mono-crystalline multi-crystalline silicon ribbon a-si / c-si CdTe CIGS DSC Polymer OPV SM-OPV 3

4 technology status Wafer-Based Silicon Mono c-si Multi c-si Best lab cell efficiency 25% 20% Commercial module 15-20% 14-17% Thin Film a-si/ c-si CdTe CIS/CIGS Best lab cell efficiency 13% 19% 20% Commercial module 7-10% 9-13% 10-14% Emerging DSC Polymer SM-OPV Best lab cell efficiency 12% 11% 12% Today s module eff. 3-5% 3-5% - 4

CIS/CIGS Best lab cell efficiency 13% 19% 20% Commercial module 7-10% 9-13% 10-14%

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 market Share market share & trend 88% of PV production (2011) is wafer-based crystalline silicon technology (c-si) Market share of

5 market Share market share & trend 88% of PV production (2011) is wafer-based crystalline silicon technology (c-si) Market share of c-si technology >80% for past 13 years Output by Technology (2011) 100% 80% a-si CIS multi-si 57% mono-si 31% CdTe 6% TF-Si 3% CIS 2% 60% 40% 20% 0% CdTe ribbon-si multi-si mono-si Source: Photon International 5

technology >80% for past 13 years Output by Technology (2011) 100% 80% a-si CIS multi-si 57% mono-si

6 c-si PV value chain MG Si Polysilicon Crystal Wafer Cell Module 6

Carbo-thermic reduction of quartz Si + HCl = SiHCl 3 Fractional

7 Case Study 1 Silicon polysilicon production Metallurgical Grade Si Siemens process for semiconductor grade Si (polysilicon) Carbo-thermic reduction of quartz Si + HCl = SiHCl 3 Fractional Reduction in H 2 distillation SiHCl 3 to Si cost ~$2/kg ~$20/kg 300,000 MT/year 7

8 polysilicon price ($/kg) silicon price Pre-2005 PV industry used scrap Si from semiconductor industry at price ~$20/kg 58% PV share of polysilicon output PV electronics 12% 8% 6% 20% 32% 45% 42% Around 2005 PV consumption of polysilicon matched semiconductor industry where price ~$50/kg Rapid growth in PV exceeded supply and spot price increased to $500/kg at peak Subsequent expansion in polysilicon production has resulted in excess supply and price fall to ~$20/kg 88% 92% 94% 80% 68% 55% 58% 42% Solar-grade silicon price trend 0 8

growth in PV 2005-2008 exceeded supply and spot price increased to $500/kg at peak Subsequent expansion in polysilicon production has resulted in

Source: IRENA Renewable Energy Technologies: Cost Analysis, Solar PV 2012 PV cost reduction The actions The outcome Before the Si price spike the PV modules cost was ~$4/Wp of which ~$1/Wp was the

9 Source: IRENA Renewable Energy Technologies: Cost Analysis, Solar PV 2012 PV cost reduction The actions The outcome Before the Si price spike the PV modules cost was ~$4/Wp of which ~$1/Wp was the silicon cost The industry response was to reduce Si consumption from 15 g/wp to 5 g/wp by Thinner wafers Reduced kerf loss Higher yields Increased recycling Higher efficiency At the same time the polysilicon industry significantly increased capacity (3-year lead-time) Temporary increase in module price Silicon cost in PV module reduced from $1.00 to $0.20/Wp and c-si remains cost-leading technology * Spot price for c-si module in Germany week 8/2013 was 0.53/Wp ($0.70/Wp) 9 *

Increased recycling Higher efficiency At the same time the polysilicon industry significantly increased capacity (3-year lead-time) Temporary increase in module price

10 Case Study 2 Silver used for electrodes (contacts) Electrical contacts are made to the top and bottom surfaces of the silicon cell These contacts are used to interconnect cells in a module and carry current to external circuit Silver-loaded paste is screen printed on the silicon and heated to 780 C to form Ohmic contact to silicon Silver is not detrimental to cell performance, is inert to firing temperature and produces a surface to which metal ribbon can be readily soldered. 10

Silver-loaded paste is screen printed on the silicon and heated to 780 C to form Ohmic contact to silicon Silver is not

11 silver - cost challenge Remarkable reductions in PV module cost have been achieved over recent years but rising silver metal price has limited cost reduction in cell fabrication Best-practice wafer-to-cell conversion cost <$0.20/Wp Typical silver paste cost $0.09/Wp paste consumption ~300 mg/cell 156mm silver cost $ 1.10/g silver cost in wafer $ 0.33/cell ($0.09/Wp) module cost breakdown wafer silicon silver cell process module 11

conversion cost <$0.20/Wp Typical silver paste cost $0.

12 sources: The Silver Institute PR 7 Apr 2011 and Photon International sliver demand Industrial demand for silver 55% of supply Prime industrial use is electrical & electronics PV consumes around 6% of demand but increasing with market growth No shortage of silver but supply driven by mining and price MT 30,000 25,000 20,000 15,000 10,000 5,000 - MT 20,000 15,000 10,000 5,000-30,000 net gov. sales 25,000 recycle 20,000 mine 15,000 production 10,000 supply 5,000 (2010) Industrial Demand for Silver e 2012e 2013e 2014e 2015e - coins & medals silverware jewelry photography industrial demand (2010) other ethylene oxide solder & brazing electrical & electronic PV 12

10,000 5,000 - MT 20,000 15,000 10,000 5,000-30,000 net gov.

base metal alternatives Nickel plated contacts were used in PV cells in the early 80 s by Solarex and Motorola Requires on-cell mask (e.g. photolith.

13 base metal alternatives Nickel plated contacts were used in PV cells in the early 80 s by Solarex and Motorola Requires on-cell mask (e.g. photolith.) for electroless Ni deposition Oxidation of nickel and copper limit their use in printed and fired pastes Copper an ideal conductor (92% conductivity Ag) but a detrimental impurity in silicon 2-layer Ni/Cu offers an effective solution Ni plating of solar cells - US DoE/JPL funded work April

) for electroless Ni deposition Oxidation of nickel and copper limit their use in printed and fired pastes

14 Ni/Cu/Sn plate v Ag print Attribute Ag Screen Print Ni/Cu/Sn Plating Lower material cost Ag price $1200/kg Cu price $9/kg Narrow line width m m Lower Resistivity 3-10 Ω.cm 1.7 Ω.cm Lower contact resistance sensitive to firing temp. <1 mω.cm 2 Higher aspect ratio (h:w) Range 1:10 to 1:2 1:2 or better Lower firing temperature C C Screen Print Ag paste 780 C fire-through SiN Copper - more complex process but lower cost and improved performance Laser pattern SiN Ni plate 350 C sinter Ni-Si Cu plate + Sn cap 14

cm 2 Higher aspect ratio (h:w) Range 1:10 to 1:2 1:2 or better Lower firing temperature 750-800 C 350-400 C Screen Print Ag paste 780

15 early adopters (of Cu) Pioneered by In production today Pilot production or R&D Source: Ji-sun Kim (Shinsung Solar) et al., PVSC

16 module price ($/Wp) summary (from case 1 & 2) A 3-fold decrease in Si consumption per Wp and a 2-fold decrease in Si price has driven c-si to a low price High silver price is driving a range of short-term silver paste-reduction initiatives but copper-based contacts provide a long-term solution to sustainable cost reduction Message Factory-gate c-si module prices Dec-08 Dec-09 Dec-10 Dec-11 Dec-12 Source: Photon Consulting Incumbent industries will find innovative ways to overcome material shortages or price escalation 16

long-term solution to sustainable cost reduction Message 3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.

FRAUNHOFER INSTITUTE FOR SOLAR ENERGY SYSTEMS ISE

FRAUNHOFER INSTITUTE FOR SOLAR ENERGY SYSTEMS ISE Photovoltaics Report Freiburg, December 11, 2012 www.ise.fraunhofer.de CONTENT Introduction Executive Summary PV Market Solar Cells / Modules / System