Impact of Materials Prices on Cost of PV Manufacture Part I - PowerPoint PPT Presentation

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

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 Candelise & Mason / SMEET II 27Feb13 2

technology platforms flat-plate sun-tracking concentrator Crystalline Silicon Thin Film Emerging DSC a-Si / c-Si mono-crystalline Polymer OPV CdTe multi-crystalline SM-OPV CIGS silicon ribbon Candelise & Mason / SMEET II 27Feb13 3

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% - Candelise & Mason / SMEET II 27Feb13 4

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 100% a-Si Technology (2011) 80% CIS market Share CdTe 60% CdTe multi-Si 6% 57% ribbon-Si 40% CIS 2% multi-Si 20% mono-Si 31% TF-Si mono-Si 0% 3% 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Source: Photon International Candelise & Mason / SMEET II 27Feb13 5

c-Si PV value chain MG Si Polysilicon Crystal Wafer Cell Module Candelise & Mason / SMEET II 27Feb13 6

Case Study 1 – Silicon polysilicon production Metallurgical Siemens process for semiconductor grade Grade Si Si (polysilicon) Carbo-thermic Fractional Reduction in H 2 reduction of Si + HCl = SiHCl 3 distillation SiHCl 3 to Si quartz ~$20/kg cost ~$2/kg 300,000 MT/year Candelise & Mason / SMEET II 27Feb13 7

silicon price PV share of polysilicon output PV electronics Pre-2005 PV industry used scrap Si 6% 8% from semiconductor industry at 12% 20% 32% 42% 45% price ~$20/kg 58% 94% Around 2005 PV consumption of 92% 88% 80% 68% 58% polysilicon matched semiconductor 55% 42% industry where price ~$50/kg 2005 2006 2007 2008 2009 2010 2011 2012 Rapid growth in PV 2005-2008 exceeded supply and spot price Solar-grade silicon price trend 200 increased to $500/kg at peak polysilicon price ($/kg) 150 Subsequent expansion in polysilicon production has resulted in excess 100 supply and price fall to ~$20/kg 50 0 Candelise & Mason / SMEET II 27Feb13 8

PV cost reduction Source: IRENA Renewable Energy Technologies: Cost Analysis, Solar PV 2012 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 Temporary increase in module price 2005-2010 At the same time the polysilicon Silicon cost in PV module reduced from $1.00 to industry significantly increased $0.20/Wp capacity (3-year lead-time) 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) Candelise & Mason / SMEET II 27Feb13 9

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 Candelise & Mason / SMEET II 27Feb13

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 module cost breakdown Typical silver paste wafer cost $0.09/Wp silver silicon cell paste consumption ~300 mg/cell 156mm process silver cost $ 1.10/g module silver cost in wafer $ 0.33/cell ($0.09/Wp) Candelise & Mason / SMEET II 27Feb13 11

sliver demand MT sources: The Silver Institute PR 7 Apr 2011 and Photon International 8-2011 30,000 30,000 • net gov. sales Industrial demand for coins & medals 25,000 25,000 silver 55% of supply silverware recycle 20,000 20,000 jewelry • Prime industrial use is 15,000 mine photography 15,000 electrical & electronics production industrial 10,000 10,000 • PV consumes around 6% supply demand of demand but increasing 5,000 5,000 (2010) (2010) with market growth - - MT • No shortage of silver but Industrial Demand for Silver 20,000 other supply driven by mining 15,000 ethylene and price oxide 10,000 solder & brazing electrical & 5,000 electronic PV - 2008 2009 2010 2011e 2012e 2013e 2014e 2015e Candelise & Mason / SMEET II 27Feb13 12

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 1980 Candelise & Mason / SMEET II 27Feb13 13

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 50-120 m 20-40 m Lower Resistivity 3-10 Ω .cm 1.7 Ω .cm sensitive to firing temp. <1 m Ω .cm 2 Lower contact resistance Higher aspect ratio (h:w) Range 1:10 to 1:2 1:2 or better Lower firing temperature 750-800 C 350-400 C Laser pattern SiN Screen Print Ag paste Ni plate 780°C fire-through SiN 350°C sinter Ni-Si Copper - more complex process but Cu plate + Sn cap lower cost and improved performance Candelise & Mason / SMEET II 27Feb13 14

early adopters (of Cu) Pioneered by In production today Source: Ji-sun Kim (Shinsung Solar) et al., PVSC 2011 Pilot production or R&D Candelise & Mason / SMEET II 27Feb13 15

summary (from case 1 & 2) A 3-fold decrease in Si consumption per Wp and a 2-fold decrease in Si Factory-gate c-Si module prices 3.50 price has driven c-Si to a low price 3.00 module price ($/Wp) High silver price is driving a range of 2.50 2.00 short-term silver paste-reduction 1.50 initiatives but copper-based 1.00 contacts provide a long-term 0.50 solution to sustainable cost 0.00 Dec-08 Dec-09 Dec-10 Dec-11 Dec-12 reduction Source: Photon Consulting Message Incumbent industries will find innovative ways to overcome material shortages or price escalation Candelise & Mason / SMEET II 27Feb13 16