Photovoltaics - energy from the sun

Transcription

1 Photovoltaics - energy from the sun Peter ommer-larsen, Torben Damgaard Nielsen, and Frederik C. Krebs Risø National Laboratory for ustainable Energy Technical University of Denmark Frederiksborgvej 399 DK-4000 Roskilde, Denmark

2 Break through for Photovoltaics (PV)? olceller foran globalt gennembrud Udklip fra Børsen 17/ omkring PG&E s ordrer på 800 MW solcellefarm i Californien. UDKLIP fjernet 2 Risø DTU, Technical University of Denmark

3 Market, capacity and price Cummulative installed PV capacity (in MWp) (MW) Insta alled PV power ROW U Japan EU ource: IEA-PVP Trends in Photovoltaic applications.( data) Marketbuzz 2007, 2008 ( data, 3 Risø DTU, Technical University of Denmark

4 Market, capacity and price Market 2007: The global PV market corresponded to 2826 MW installed capacity in The panish market increased 480% from Global PV market ROW ROE 8% UA 6% % 5000 Japan 8% (MW) Insta alled PV power pain 23% ROW U Japan EU Germany 47% ource: Marketbuzz Risø DTU, Technical University of Denmark

5 Market, capacity and price Prices for solar cell modules have not changed $ / W (MW) Module price ROW U Japan EU ource: Risø Energy Report 6 (2007) Insta alled PV power 2000 Year ource: IEA-PVP Trends in Photovoltaic applications.( data) Marketbuzz 2007, 2008 ( data, 5 Risø DTU, Technical University of Denmark

6 Incentive mechanisms key policy measures Feed-in tariff (FIT): The renewable energy producer is guarantied a tariff for the produced electrical energy over an extended period typical 20 years. Net-metering : The renewable energy producer is paid the market tariff. A single reversible electricity meter is the preferred options for homeowners exporting to the grid. Investment support: in form of subsidies, tax facilities or subsidized low-interest rates. Denmark: Net-metering Germany: FIT guaranteed over 20 years 2009: 0.32/kWh ground mounted /kWh BIPV depending on size pain: FIT guaranteed over 25 years 2008: 0.45/kWh 2009: 0.32/kWh, small rooftop systems 0.34/kWh. 500 MWp max 2010: 0.32/kWh, small rooftop systems 0.34/kWh. 450 MWp max Target 3000 MW capacity by end of U: FIT bill proposed with technology dependent tariffs California: i FIT and net-metering. 6 Risø DTU, Technical University of Denmark

7 Market, capacity and price By 2016, the global installed PV capacity is comparable to Wind turbine capacity today ROW U Japan Installe ed PV power (M MW) EU Risø DTU, Technical University of Denmark

8 Roadmaps and visions 200 GWp installed PV capacity in EU by 2030 and 4% of the global electricity demand (A Vision for Photovoltaic Technology, Report by the Photovoltaic Technology Research Advisory Council (PV-TRAC), EU 2005) A trategic Research Agenda for Photovoltaic olar Energy Technology Research and development in support of realising the Vision for Photovoltaic Technology, EU PV Technology Platform (PVTP), EU Risø DTU, Technical University of Denmark

9 40 GW production capacity by 2012! The European Commissions Joint Research Centre in their 2008 status report assessed the planned increase in the PV industry s production capacity. The assessment of the Industry s s own plans sums to a global production capacity og 40 GW by 2012!!! The growth of the PV industry has year for year exceeded even the most optimistic scenarios from previous years. o there is good reason to have confidence in the industry s own expectations 9 Risø DTU, Technical University of Denmark

10 Basics Cells are interconnected in series and parallel into modules and modules are collected into panels. 15 x 15 cm 0.5 V / 4A 75 W: 18 V / 4A A solar cell system include balance-of-system technology: Inverters, cables, frames, electricity meter Danfoss solar Inverters Dr-taget Kilde ATV-EMAPP 10 Risø DTU, Technical University of Denmark

11 Efficiencies, power and energy output olar cells are rated at standard test conditions (TC): solar irradiance of 1000W/m 2 solar reference spectrum AM1.5G 25 C. A 75 Wp (Watt peak) module delivers 75 W under TC. 1 kwp system produces 850 kwh/year in Denmark 11 Risø DTU, Technical University of Denmark

12 Characterisation of PV The IV-curve P η = P max light tandard test conditions: P light = 1000 W/m 2 T = K olar reference spectrum AM1.5G P max =I V V OC + V - I I C 12 Risø DTU, Technical University of Denmark

13 Efficiency limits, efficiency tables 30% limit (hockley, W., Queisser H.J., 1961, Detailed balance limit of efficiency of P-N junction solar cells, Journal of Applied Physics, 32(3): ) 32 nd version of olar Cell Efficiency Tables (Green, M.A., Emery, K., Hishikawa, Y., Warta, W., 2008, (Version 32), Prog. Photovolt: Res. Appl.; 16: ) Technology Cell Module comment 1 st generation Mono c-i 24.7% 22.7% Poly c-i 20.3% 15.3% Mono c-gaas 25.9% 2 nd generation Amorphous i 9.5% 8.2% CIG 19.2% 13.4% CdTe 16.5% 10.7% 3 rd generation Dye sensitized 10.4% 8.2% Organic Polymer 5.2% High efficiency GaInP/GaAs/Ge 32.0% Multijunction GaInP/GaInAs/Ge 40.7% Multijunction, concentrator (240 suns) Mono c-i 27.3% Concentrator (93 suns) 13 Risø DTU, Technical University of Denmark

14 Multijunction - tandem PV Triple-junction PV: GaInP: >1.8 ev light absorbed GaAs: 1.4 ev to 1.8 ev absorbed Ge: 0.7 ev to 1.4 ev absorbed pectrolab Inc. η = 41% Theoretical limits: ingle junction cell 31% Infinite-junction cell 65% + concentration 85% nm -1 ) Intensity (W m -2 2,0 1,5 1,0 0, GaInP 1.8 ev GaAs 1.4 ev Ge 0.7 ev , hν (ev) 14 Risø DTU, Technical University of Denmark

15 Concentrating PV olfocus 500 x concentration 15 Risø DTU, Technical University of Denmark

16 Efficiency limits, efficiency tables 30% limit (hockley, W., Queisser H.J., 1961, Detailed balance limit of efficiency of P-N junction solar cells, Journal of Applied Physics, 32(3): ) 32 nd version of olar Cell Efficiency Tables (Green, M.A., Emery, K., Hishikawa, Y., Warta, W., 2008, (Version 32), Prog. Photovolt: Res. Appl.; 16: ) Technology Cell Module comment 1 st generation Mono c-i 24.7% 22.7% Poly c-i 20.3% 15.3% Mono c-gaas 25.9% 2 nd generation Amorphous i 9.5% 8.2% CIG 19.2% 13.4% CdTe 16.5% 10.7% 3 rd generation Dye sensitized 10.4% 8.2% Organic Polymer 5.2% High efficiency GaInP/GaAs/Ge 32.0% Multijunction GaInP/GaInAs/Ge 40.7% Multijunction, concentrator (240 suns) Mono c-i 27.3% Concentrator (93 suns) 16 Risø DTU, Technical University of Denmark

17 Three generations of solar cells 1 st: Crystalline ilicon solar cells 20% Expensive Low volume 2 nd: Thin film technology (amorphous i, CdTe, CIG) 8 (to 20%) Cheaper Higher volume 3 rd: organic and polymer solar cells 1 (to 5%) Extremely cheap Extremely high volume Well tech. Monocrystalline i panel Cut from ingots Uni-olar amorphous i flexible panel roll-to-roll processing (slow) Risø DTU solar cell printed on textile. creen print (fast) 17 Risø DTU, Technical University of Denmark

18 Thin film PV (2 nd generation) 44% of U production is thin film PV (only 6% globally) (2006) First olar (Perrysburg, Ohio CdTe: 10.7% (module) to 16.5% (cell) Target: 450 MW capacity (2010) and 0.70 $/Wp (2012) A 40MW thin-film CdTe solar field being built in axony, Germany to be completed in early 2009 by First olar and Juwi olar. Installed system price 3.25$ / Wp 18 Risø DTU, Technical University of Denmark

19 Thinfilm solar farm in Nevada reach grid parity First solar has recently commenced a 10 MW CdTe solar cell farm in Nevada for empra Generation. The installation is estimated to produce power at a price of 7.5 cents/kwh below the average U electricity price of 9 cents/kwh Beware that grid parity is not really a target for solar power plants. Their production price should be compared to other renewable energy sources. Take an example, EON won the second public bit for Rødsand II off-shore windmill farm at a price of 62,9 øre/kwh (Ingeniøren 25/4-2008). 19 Risø DTU, Technical University of Denmark

20 cientific focus on 3 rd generation cells 20 Risø DTU, Technical University of Denmark

21 Dye sensitized solar cells (DC) and polymer solar cells (3 rd generation) O'Regan Regan, B., Grätzel, M., 1991, A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films, Nature 353(6346): % efficiency demonstrated. Dye-sensitized solar cells separate the functions provided by a semiconductor solar cell: Absorption of light occurs in a dye absorbed on a nonporous TiO2 layer. Charge separation occurs at the interface between the dye and the electron conducting TiO2. Electron transport: to the transparent conducting oxide electrode ect through the TiO2. Hole transport:diffusion of iodide to the dye, which extract electrons from the iodide and oxidizes it to triiodide. Reduction of triiodide at the Pt-electrode, when the generated electron is transferred through an outer circuit. The cell is also called a Grätzel cell after its inventor. 21 Risø DTU, Technical University of Denmark ITO TiO 2 e - I - - I 3 Pt

22 DC G24i (Cardiff,Wales) manufacture and markets(?) thin film DC technology based on coating process Powerboard eries Efficient solar powerboard for endless mobile talk time olar phone charger with integrated AA cell, cell battery optional models for universal charging options + reading lights Works in low light conditions Ultra-compact, light, hard wearing and durable 22 Risø DTU, Technical University of Denmark

23 Polymer solar cell Yu, G., Gao, J., Hummelen, J.C., Wudl, F., Heeger, A.J., 1995, Polymer photovoltaic cells - enhanced efficiencies via a Network if internal donoracceptor heterojunctions, cience, 270(5243): Bulk hetero junction: Aluminium Active layer Volt ITO ubstrate un light 23 Risø DTU, Technical University of Denmark

24 How it works absorption of light * 24 Risø DTU, Technical University of Denmark

25 How it works electron transfer from donor to acceptor e - 25 Risø DTU, Technical University of Denmark

26 How it works generation of charge carriers e - h + 26 Risø DTU, Technical University of Denmark

27 How it works charge carrier diffusion e - h + 27 Risø DTU, Technical University of Denmark

28 Risø DTU polymer solar cell group Dr. Frederik Christian Krebs (head of group) Dr. Mikkel Jørgensen (organic synthesis) Dr. Kion Normann (characterisation) Dr. Jenz Wenzel Andreasen (structure) Dr. Kristian O. ylvester-hvid (device physics) Dr. Eva Bundgaard (synthesis) Msc. Martin H. Petersen (synthesis) Msc. uren Gevorgyan (processing) Msc. Roar øndergaard (synthesis) Msc. Mette Mikkelsen (solar energy conversion) Ole Hagemann (Lab. tech. synthesis) Jan Alstrup (Lab. tech. processing) Msc. Torben D. Nielsen (commercialisation) 28 Risø DTU, Technical University of Denmark

29 Risø DTU polymer solar cells The overall objective: To develop a new sustainable energy technology. On shorter terms to develop polymer solar cells apt for niche products. Key focus: To unify efficiency, stability, and processability in the same material eff ficiency 5.9% stability years processability screen print on textile Hertz & Langberg Risø DTU, Technical University of Denmark

30 Efficiency 6.5% For tandem cells > 99.9 % of scientific reports have efficiency as the selling point > 99.9 % of scientific reports employ spin coating > 99.9% of scientific reports employ evaporated metal back electrodes > 99.9% of scientific reports employ indium based transparent electrodes cience 317 (2007) Risø DTU, Technical University of Denmark

31 New processing techniques are needed Low cost Fast R2R Ambient air No vacuum steps Environmentally friendly ol. Energy Mater. ol. Cells 92 (2008) Risø DTU, Technical University of Denmark

32 New materials are needed Thermocleavable materials What are they? FC Krebs et al., Chem. Mater. 17 (2005) Risø DTU, Technical University of Denmark

33 The solar hat a public demonstration lide describing the first large scale public demonstration of polymer solar cells ever is deleted for publication reasons. Risø demonstrated the technology at Roskilde festivalen The same modules were used for demonstration in ct. James Park, London, see slide Risø DTU, Technical University of Denmark

38 t. James Park (Loop.PH, London) 38 Risø DTU, Technical University of Denmark

39 Incresing efforts in polymer PV Konarka Technologies, Inc., MA, U Plextronics, U (5.9% with spincoated ink) A new research group a week Bundesministerin Dr. Annette chavan und die Vorstände von BAF, Bosch, Merck und chott haben am 27. Juni 2007 in Frankfurt eine gemeinsame Technologieinitiative für Organische Photovoltaik gestartet, für die sie in den kommenden Jahren 360 Mio. bereitstellen wollen. 60 Mio davon steuert das BMBF bei 39 Risø DTU, Technical University of Denmark

40 Conclusions PV will become a major renewable energy technology New generations of PV has the potential for cheap, easy and large scale production - the basis for visions where 25% of global electricity production is covered by PV in Feed-in-tariffs is the key incentive for building a European PV industry. A constant struggle for lower productions prices. Target is a module price of 1$/Wp. 50% efficiency is targeted by multi-junction solar cells combined with solar concentration. 6% efficiency has been demonstrated for polymer solar cells >1 years stability has been demonstrated Challenges for polymer solar cells are to unify stability and efficiency with ease of production. New materials are needed. 2-3% efficiency for coated polymer solar cells within reach with years stability Demonstration is a corner stone 40 Risø DTU, Technical University of Denmark

41 Conclusion On the global level, there is no doubt that photovoltaics will become a major renewable electricity source and most likely the major electricity source! There is a very good reasons to expect a continued price reduction. This will bring solar electricity on par with (and below) the average electricity price in Denmark before Hence Denmark should already now prepare for the challenge of installing solar cells in massive amounts. Yes, Denmark has an excellent position to take place in the continued R&D of technological breakthroughs in PV (like polymer solar cells) that continues the very positive progress of the PV area. And yes, PV is already a new Windmill adventure on the global scale. 41 Risø DTU, Technical University of Denmark