Innovative Coloured Solar Glass for Enhanced Building Integration of Solar Energy Systems

1. JUNE 4 & 5, 2014 | BEIRUT, LEBANON Innovative Coloured Solar Glass forEnhanced Building Integration ofSolar Energy Systems Dr. Andreas Schüler Research Group Leader Laboratory of Solar Energy and Building Physics LESO-PB EcolePolytechniqueFédérale de Lausanne EPFL Dr. Virginie Le Caër Head of Research and Development SwissINSO SA

2. Laboratory of Solar Energy and Building Physics : leso-pb ADVANCED DAYLIGHTING TECHNOLOGIES Prof. J.-L. Scartezzini SUSTAINABLE URBAN DEVELOPMENT Dr. N. Mohajeri BIOMIMETIC BUILDING TECHNOLOGIES Dr. V. Nik NANOTECHNOLOGY FOR SOLAR ENERGY CONVERSION Dr. A. Schüler ARCHITECTURAL INTEGRATION OF RENEWABLE ENERGY TECHNOLOGIES C. Roecker, Dr. M. C. Munari Probst 2

3. Context Few years ago Solar devices often considered as technical components to be hidden and confined to roof-top applications PV modules Thermal collectors Both types of panels

4. Context Nowadays New building-integrated products of enhanced visual aspect BETTER BUT still limited architectural integration Not many Building Integrated Solar Thermal products on the market Dark appearance and visibility of technical parts for both BIPV and BIST systems

5. Various Attempts to Overcome this Drawback Photovoltaic modules Thermal collectors Frame Frame Solar glass Solar glass Insulation Laminating polymer Black absorber PV cells Tubing Laminating polymer Casing Backing plate Junction box

6. Various Attempts to Overcome this Drawback Photovoltaic modules Thermal collectors Organic cells Coloured thin films Coloured cells Coloured absorbers Dye-sensitized cells Main problems Low efficiency Limited long-term durability Colour fading Visibility of tubing or electrical contacts

7. Coloured solar panels Coloured thin films Coloured cells Organic cells Novel Façade with Graetzel Cells SwissTech Convention Center on EPFL campus 300 m2, estimated 8’000 kWh/yr Industrial partners: Solaronix, Romande Energie

8. Coloured solar panels PV modules based on a-Si thin films Coloured a-Si PV modules L.-E. Perret-Aebi, C. Ballif et al., PV-Lab EPFL Typical conversion efficiency in the order of 10% reduced a-Si film thickness, coloured back reflector

9. Coloured solar panels Crystalline PV modules Colouration by modification of the PV cells Solar glass Laminating polymer PV cells Backing plate Junction box Changing the front end of production, visibility of electrical contacts, 15 to 40% loss of efficiency Typical efficiency ranging from 15 to 20%

10. Coloured solar panels Flat plate solar thermal collectors Replacement of the black absorber by coloured ones Glazing Black absorber Tubing Visibility of tubing, corrugations, welding traces Insulation Casing

11. A novel breakthrough solution Novel coloured solar glazing with high energetic transmittance: KROMATIX™ • Attractive colours • Mat outer surface • Minimized energy losses • Applicable to both thermal and PV panels PV modules Thermal collectors

12. Coloured Multilayered Coating Reflection of a small part of the visible light to provide the colour. Transmission of the rest of the solar spectrum to be converted into energy. Solar spectrum AM1.5g Coloured coating Coloured reflection of a spectral band Spectral irradiance (W.m2.nm-1) Incident radiation Glass reflection Transmitted radiation Coloured reflection Glazing • Optimisation of the multi-layered coating in order to • Obtain the desired colour • Find the best compromise between colour saturation and energetic performances

13. Outer Surface Treatment • Modification of the outer surface roughness that provides diffuse reflection: • To reinforce the masking effect of the technical parts of the solar device • To prevent glare effects (mat surface) Diffusive surface Coloured coating Incident radiation Diffuse coloured reflection Transmitted radiation Glazing Patterning of outer diffusive surface possible: graphics, logo

14. Laboratory development plasma duringprocessing Thin film deposition by reactivemagnetroncosputtering

15. Examples of Coloured Coated Glass Large variety of tuneable colours Patterning of satinated surface Orange Yellow Reddish- orange Yellowish- orange Blue Green Violet-blue Bluish-green

16. Energetic performances Solar thermal collector 100 80 Transmitted radiation to be converted into solar energy 60 Reflectance (%) 40 20 0 1500 2500 500 1000 2000 uncoated glass Wavelength (nm) Surface of standard solar glazing: colourless

17. Energetic performances Solar thermal collector 100 80 Transmitted radiation to be converted into solar energy 60 Reflectance (%) 40 20 efficiency losses 0 blue coated glass 1500 2500 500 1000 2000 uncoated glass Wavelength (nm) With coating: energetic performances depend on the chosen colour

18. Energetic performances Photovoltaic module: example of crystalline cells 100 80 60 Useful transmitted radiation Reflectance (%) 40 20 0 1500 2500 500 1000 2000 uncoated glass Wavelength (nm) Surface of standard solar glazing: colourless

19. Energetic performances Photovoltaic module: example of crystalline cells 100 80 60 Useful transmitted radiation Reflectance (%) 40 efficiency losses 20 0 blue coated glass 1500 2500 500 1000 2000 uncoated glass Wavelength (nm) With coating: higher energetic losses for PV panels as compared to thermal collectors

20. Examples GREY Solar transmittance: 91 % Relative energetic losses: 1 % for thermal 2 % for PV BLUE Solar transmittance: 89 % Relative energetic losses: 3 % for thermal 4 % for PV GREEN Solar transmittance: 89 % Relative energetic losses: 3 % for thermal 5 % for PV TERRACOTTA Solar transmittance: 88 % Relative energetic losses: 4 % for thermal 8 % for PV

21. Industrial Production Deposition of coloured coating Homogeneous or selective etching Cutting to size Tempering Extra white solar glass On-site installation Solar panel assembly

22. Examples of Coloured Solar Panels Photovoltaic framed modules Photovoltaic tiles Thermal collectors Photovoltaic glass/glass modules

23. Building Integration Roofs Coloured PV modules and solar thermal collectors and non-active elements Same colour as natural roof tiles Ventilated glass façades Homogeneous appearance: PV and/or thermal panels + non active elements on North façade and areas submitted to high shadowing effects Key benefits: Maximum use of the building envelope to collect solar energy.

24. Roof Integration Novelsolartiles • minimized energy losses by interference filter • novel glazing suitable for PV, T and PV&T mixed project ARCHINSOLAR S. Pélisset, M. Joly, A. Schüler, S. Mertin, V. Hody-Le Caër, C. Ballif, L.-E. Perret-Aebi CISBAT 2011, Lausanne

25. Roof Integration Residential home near Lausanne Photovoltaic modules +/- 100 sqm = 12 MWh/year Thermal collectors +/- 30 sqm

26. Façade Integration April 2013: Test of façade installation in Valais Glass/glass frameless PV modules - Special invisible mounting system

27. Façade Integration Coming soon: façade refurbishment at EPFL PV modules with selective outside treatment PV modules with uniform outside treatment Gauge: indication of the real-time production of Romande Energy solar park, installed on EPFL’s roofs Non active elements

28. Building Integration Coming soon: Residential building in Basel North facade Non-active elements in 4 colours. +/- 10 sqm South and West facades Thin film frameless PV modules in 4 colours. +/- 70 sqm of panels and 6.5 MWh/year. Roof Crystalline framed PV modules in 4 colours. +/- 80 sqm of panels and 9.5 MWh/year. Total production 16 MWh/year = average annual needs for 4 families

29. Nature Integration Solar farm in UK Solar farm in UAE Appearance with standard solar glazing Simulations with novel coloured solar glazing

30. Commercialization SwissINSOsa • Swiss company – offices at EPFL/PSE • R&D to improve solar panel aesthetics, usage and performances • Coloured solar glass applicable to photovoltaic modules, solar thermal collectors and cladding elements – developed in collaboration with EPFL/LESO-PB • Custom-sized thermal collectors and PV modules • New products for roof installation and refurbishment – partially developed in collaboration with EPFL/PV-Lab and LTC • New concepts for façade integration

31. Acknowledgements Solar Energy Laboratory LESO @ EPFL André Kostro, Martin Joly, Antonio Paone, Olivia Bouvard, Nicolas Jolissaint, Estelle de Chambrier, Deepanshu Dutta, Hitesh Chelawat, Pierre Loesch, Laurent Deschamps, Maria-Cristina Munari-Probst, Christian Roecker, Prof. Jean-Louis Scartezzini Collaborations on campus EPFL Rosendo Sanjines (LPMC), Y. Leterrier, R. Teuscher (LTC), Aïcha Hessler, Danièle Laub (CIME), P. Flückiger, C. Hibert (CMI), Michel Schaer, Prof. Libero Zuppiroli (LOMM) University of Basel Jamila Boudaden, Roland Steiner, Prof. Peter Oelhafen SPF Rapperswil Paul Gantenbein, Stefan Brunold, Prof. Matthias Rommel PV-Lab Neuchâtel Laure-Emmanuelle Perret-Aebi, Ségolène Pélisset, Christian Schlumpf, Valentin Chapuis, Prof. Christophe Ballif Financial support Swiss Federal Energy Office SFOE Swisselectric Research SER Commission for Technology and Innovation Switzerland CTI Swiss National Science Foundation SNF 31

32. Thank you for your attention!