Photovoltaics: Status and Perspectives Paul Wyers
Photovoltaic conversion: typical device structure of silicon solar cell anti-reflection coating sunlight _ front contact n-type Si solar cell heat electricity (+) (-) p-type Si back contact
Energy reserves in perspective
Solar resource solar irradiation in kwh/m 2. day (source: ABB, 1998)
The role of photovoltaics in the future energy supply WBGU scenario
Approximate market shares Off-grid industrial 10% Off-grid rural 5% Grid connected power plants 5% Consumer 5% Grid connected integrated in buildings & other 75%
The PV Market 1999-2005 yearly growth of 30-65% in past 7 years volume 2005 of 1640 MWp (14 km 2 ) turnover 2005 of $ 5.3 billion (PiperJaffray, October 2005) cell production (MWp) 1800 1600 1400 1200 1000 800 600 400 200 0 1999 2000 2001 2002 2003 2004 2005
Requirements for very large-scale use Turn-key system price < 1 /Wp Excellent environmental profile
Learning curve PV modules technology and volume [2001 $] Power Modules (1976-2001) 100 1976 1983 1990 10 1981 1987 2001 Price of Power Modules (2001 $) Estimate 1976-2001: PR = 80.0±0.4% Estimate 1987-2001: PR = 77.0±1.5% 1 0 1 10 100 1000 10000 Cumulative Shipments [MW p] power modules (SU, 2003) source: EU Photex project 2003?
Expected evolution of turn-key photovoltaic system prices typical turn-key system price ( /Wp) 5 4 3 2 1 0 BOS 2004 2010 2020 2030 2050 modules BOS = Balance-Of-System year http://europa.eu.int/comm/research/energy/pdf/vision-report-final.pdf
2005 PV electricity price ( / kwh) 0.50 consumer electricity price ( / kwh) 0.22 PV electricity prices compared with typical consumer electricity prices 0.42 0.36 0.14 0.11 0.16 0.16 0.31 0.20 0.12 0.10 0.28 break-even boundary
2010 PV electricity price ( / kwh) 0.35 consumer electricity price ( / kwh) 0.23 PV electricity prices compared with expected consumer electricity prices (+ 1%/yr) 0.29 0.25 0.15 0.11 0.17 0.17 0.22 0.21 0.13 0.11 0.19
2015 PV electricity price ( / kwh) 0.25 consumer electricity price ( / kwh) 0.24 PV electricity prices compared with expected consumer electricity prices (+ 1%/yr) 0.21 0.18 0.16 0.12 0.18 0.18 0.16 0.22 0.13 0.11 0.14
2020 PV electricity price ( / kwh) 0.20 consumer electricity price ( / kwh) 0.26 PV electricity prices compared with expected consumer electricity prices (+ 1%/yr) 0.17 0.14 0.16 0.12 0.19 0.19 0.13 0.23 0.14 0.12 0.11
2030 PV electricity price ( / kwh) 0.10 consumer electricity price ( / kwh) 0.28 PV electricity prices compared with expected consumer electricity prices (+ 1%/yr) 0.08 0.07 0.18 0.14 0.20 0.20 0.063 0.15 0.13 0.26 0.055
PV technologies today Commercial: crystalline silicon technically getting mature, main vehicle for price reduction (93% of 2004 global market) Commercial: thin films emerging, overall development somewhat slower than expected (7% of 2004 global market) Laboratory & pilot production Still long way to go to professional use, first products for indoor and low power applications
PV technology development: no revolution, but evolution module price ( /Wp) 4 3 2 1 OSC technology families Thin-films Crystalline silicon 2004 2010 technology generations 2020 new concepts >2030 0 0 5 10 15 20 25 module efficiency (%) (free after W. Hoffmann)
Production process for a crystalline silicon module
Crystalline silicon PV: main challenges 1. Reduce costs Low-cost feedstock Secure silicon feedstock supply Reduce material costs Thin wafers or direct casting Alternative module materials Higher conversion efficiencies Upscaling and integration of production process 2. Improve environmental profile Avoid rare and/or hazardous materials Reduce energy pay-back time
Energy Pay-Back Time CrystalClear EU Integrated Project E.A. Alsema (UU) and M.J. de Wild-Scholten (ECN).
Volume (MT/yr) 70000 60000 50000 40000 30000 20000 Polysilicon supply and demand Source: Wacker 2 nd SoG-Si Workshop Photovoltaics: growth potential = 30% Silicon availability at growth of 10% Shortages of Polysilicon Total Capacity 10000 0 1980 1985 1990 1995 2000 2005 2010 Semiconductor demand Photovoltaics demand
Silicon losses 13 tons Si / MWp Source: Sarti,D. and R.Einhaus (2002): Silicon feedstock for the multi-crystalline photovoltaic industry; Solar Energy Materials and Solar Cells 72 (1-4): 27-40
Reducing silicon consumption: thin (sliced) wafers or direct casting of ribbons Wafer thickness [µm] Wafers/kg Si [#/kg] 270 49 200 64 150 83 Casting frame (cut) Gassing Annealing Direction Finished foils Source: Meyer&Burger 40 µm Preheating Continuous substrate
Module manufacturing costs 30% 22% silicon wafer cell module 20% 28%
Direct c-si module manufacturing costs 2005: 2 /Wp silicon wafer cell module 0.3 /Wp in 20?? 120 µm ribbons 17% efficiency Fully Integrated manufacturing (100 MWp per line, quartz-to-module)
Research focus Established R&Dperformers silicon wafer cell module
Research focus FEST-PV (ISC, ECN, ) silicon wafer cell module Research Centre for Front End Silicon Technology Scope: silicon feedstock production, ingot crystallization, wafering, cleaning
FEST on Avantis? feasibility study in progress
ECN wishes ISC a lot of Fun, Enthusiasm & Sunny Timesimes Floriade (2.3 MWp PV)