Prof. Dr. Hartmut Nussbaumer

Work at ZHAW

Position

Professor for Photovoltaics, Head of research group Photovotaic, Coordinator platform Photvoltaics

Focus

Photovoltaics

Professional development teaching

• WBK Photovoltaik, Netze und Speicher
• CAS Energiesysteme für klimaneutrale Areale und Quartiere

Experience

• CTO
  RENA GmbH
  07 / 2008 - 06 / 2014
• Managing director
  centrotherm photovoltaics technology GmbH
  06 / 2006 - 06 / 2008
• Head of Technology
  Sunways
  01 / 1998 - 05 / 2006
• Project leader
  Eurosolare SpA
  06 / 1996 - 12 / 1997

Education and Continuing education

Education

• PhD / Physics
  University of Konstanz
  07 / 1992 - 05 / 1996
• Diploma / Physics
  University of Konstanz
  10 / 1986 - 05 / 1992

Continuing Education

• Research stay
  Tyree Energy Technologies Building
  2024
• Certificate of Advanced Studies
  PH Zurich
  10 / 2016

Network

Awards

Doctor of Science with Summa cum laude
University of Kontanz
05 / 1996

Projects

• Improving the reliability and performance of photovoltaic-(PV)-systems – IEA PVPS Task 13 Swiss Consortium (2026-2029) / Project leader / ongoing
• Performance of Photovoltaic Systems under Partial Shading Conditions: From Cell to System / Project leader / ongoing
• Profitability of PV systems on green roofs / Project leader / ongoing
• PVEco – Profitability study of photovoltaic systems taking dynamic electricity tariffs into account / Project leader / ongoing
• Alpine PV Competence / Project leader / completed
• Advanced Imaging and Machine Learning for PV Quality Assurance / Team member / completed
• Ultra lightweight PV modules / Project leader / completed
• PV2050: Sustainability, market deployment and interaction to the grid – the impacts of advanced PV solutions / Team member / completed

Publications

Articles in scientific journal, peer-reviewed

• Nussbaumer, H. et al. (2020) 'Accuracy of simulated data for bifacial systems with varying tilt angles and share of diffuse radiation', Solar Energy, 197, pp. 6–21. doi: 10.1016/j.solener.2019.12.071.
• Berrian, D. et al. (2019) 'Performance of bifacial PV arrays with fixed tilt and horizontal single-axis tracking : comparison of simulated and measured data', IEEE Journal of Photovoltaics, 9(6), pp. 1583–1589. doi: 10.1109/JPHOTOV.2019.2924394.
• Nussbaumer, H. et al. (2019) 'Energy yield prediction of a bifacial PV system with a miniaturized test array', Solar Energy, 179, pp. 316–325. doi: 10.1016/j.solener.2018.12.042.
• Baumann, T. et al. (2019) 'Photovoltaic systems with vertically mounted bifacial PV modules in combination with green roofs', Solar Energy, 190, pp. 139–146. doi: 10.1016/j.solener.2019.08.014.

Written conference contributions, peer-reviewed

• Nussbaumer, H. et al. (2025) 'Measures to adapt the power output on demand by system design on rooftop PV systems', in 42nd European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC), Bilbao, Spain, 22-26 September 2025.
• Klenk, M. et al. (2024) 'PV on green roofs : two years of comparative measurement data from various system concepts, supplemented by simulation results and general considerations', in Proceedings of the 41st European Photovoltaic Solar Energy Conference and Exhibition. Munich: WIP, pp. 020371–001–020371–008. doi: 10.4229/EUPVSEC2024/4BV.4.14.
• Nussbaumer, H. et al. (2024) 'Increasing the proportion of winter electricity through design optimisation of photovoltaic roof systems', in Proceedings of the 41st European Photovoltaic Solar Energy Conference and Exhibition. Munich: WIP, pp. 020458–001–020458–004. doi: 10.4229/EUPVSEC2024/4DV.4.5.
• Nussbaumer, H. et al. (2024) 'Highest energy yields per area for PV systems on flat roofs', in Proceedings of the 41st European Photovoltaic Solar Energy Conference and Exhibition. Munich: WIP, pp. 020460–001–020460–005. doi: 10.4229/EUPVSEC2024/4DV.4.10.
• Nussbaumer, H. et al. (2023) 'Photovoltaic and green roof : energy yield per area of vertically installed bifacial modules in dense arrangements', in Proceedings of the 40th European Photovoltaic Solar Energy Conference and Exhibition. München: WIP, pp. 020424–001–020424–007. doi: 10.4229/EUPVSEC2023/4DO.12.5.
• Nussbaumer, H. et al. (2020) 'Miniaturized model kit for yield measurements of PV systems : concept and application', in Proceedings of the 2020 47th IEEE Photovoltaic Specialists Conference (PVSC). IEEE, pp. 1093–1095. doi: 10.1109/PVSC45281.2020.9300554.
• Segundo Sevilla, F. R. et al. (2018) 'State-feedback control for damping inter-area oscillations on electrical power systems', in 2018 IEEE Autumn Meeting on Power, Electronics and Computing (ROPEC 2018), Ixtapa, Mexico, 14-16 November 2018.

Other publications

• Nussbaumer, H. et al. (2019) 'PV systems with lowest LCOE using bifacial modules : state-of-the-art systems and components', PV-Tech Power, 18, pp. 16–27.
• Janssen, G. J. M. et al. (2018) 'How to maximize the kwh/kwp ratio : simulations of single-axis tracking in bifacial systems', in 35th European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC), Brussels, Belgium, 24-27 September 2018.
• Klenk, M. et al. (2018) 'Bifacial PV systems and yield data (bifacial gain)', in Kopecek, R. and Libal, J. (eds) Bifacial photovoltaics : technology, applications and economics. Institution of Engineering and Technology, pp. 153–214.
• Baumann, T. et al. (2018) 'Performance analysis of vertically mounted bifacial PV modules on green roof system', in 35th European Photovoltaic Solar Energy Conference and Exhibition. WIP. doi: 10.21256/zhaw-4034.
• Nussbaumer, H. et al. (2018) 'State-of-the-art bifacial module technology', Photovoltaics International, 2018(41), pp. 108–125.
• Nussbaumer, H. et al. (2017) 'Record-light weight c-Si modules based on the small unit compound approach : mechanical load tests and general results', in Proceedings of the 33rd European Photovoltaic Solar Energy Conference and Exhibition. WIP, pp. 146–150. doi: 10.4229/EUPVSEC20172017-1CV.3.69.
• Oreski, G. et al. (2017) 'Investigation of effects due to encapsulation thickness', in 33rd European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC), Amsterdam, Netherlands, 25-29 September 2017.
• Baumann, T. et al. (2017) 'Illumination homogeneity of bifacial systems : outdoor measurements with systematically varied installation conditions : visual', in Proceedings of the EU PVSEC 2017, pp. 1605–1609. doi: 10.4229/EUPVSEC20172017-5BV.4.28.
• Nussbaumer, H. et al. (2017) 'Application of shaped reflectors to increase the energy harvest of bifacial PV systems : analyzed with a miniaturized test array', in 2017 IEEE 44th Photovoltaic Specialist Conference (PVSC 2017) : Proceedings. IEEE, pp. 1077–1080.
• Nussbaumer, H. et al. (2016) 'Influence of low concentration on the energy harvest of PV systems using bifacial modules', in Proceedings of the EU PVSEC 2016 (Munich). WIP.
• Nussbaumer, H. et al. (2016) 'Miniaturized test array as a means to determine the energy harvest of bifacial installations', in Poceedings of the 2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC). IEEE, pp. 2698–2703. doi: 10.1109/PVSC.2016.7750140.
• Nussbaumer, H. et al. (2016) 'Miniaturized test array as a means to determine the energy harvest of bifacial installations', in IEEE PVSC 2016 : Kongress. IEEE, pp. 2698–2703. doi: 10.1109/PVSC.2016.7750140.
• Nussbaumer, H., Klenk, M. and Keller, N. (2016) 'Small unit compound modules : a new approach for light weight PV modules', in Proceedings of the 32nd European Photovoltaic Solar Energy Conference and Exhibition. WIP, pp. 56–60. doi: 10.4229/EUPVSEC20162016-1BO.12.5.
• Nussbaumer, H. et al. (2015) 'The Swiss PV wall system to maximise self-consumption in a single building element', in 31st European Photovoltaic Solar Energy Conference and Exhibition (EUPVSEC), Hamburg, Germany, 14-18 September 2015.
• Nussbaumer, H. et al. (2015) 'PV installations based on vertically mounted bifacial modules evaluation of energy yield and shading effects', in Proceedings of the 31st European Photovoltaic Solar Energy Conference and Exhibition. WIP, pp. 2037–2041. doi: 10.4229/EUPVSEC20152015-5AV.6.34.
• Horzel, J. T. et al. (2015) 'Industrial Si solar cells with Cu based plated contacts', IEEE Journal of Photovoltaics, 5(6), pp. 1595–1600. doi: 10.1109/JPHOTOV.2015.2478067.
• Baumgartner, F. et al. (2014) 'Bifacial modules used in cable based PV carport applications', in Photovoltaic science and engineering : the 6th World Conference on Photovoltaic Energy Conversion, 24th International Photovoltaic Science and Engineering Conference, PVSEC-24. Tokyo Japan Society of Applied Physics.
• Comparotto, C. et al. (2014) 'Bifacial n-type solar modules : indoor and outdoor evaluation', in Proceedings of the 29th European Photovoltaic Solar Energy Conference and Exhibition. Amsterdam: WIP, pp. 3248–3250. doi: 10.4229/EUPVSEC20142014-5CV.2.11.

Oral conference contributions and abstracts

• Nussbaumer, H. (2022) 'Photovoltaiksysteme in Kombination mit Gründächern', in 20. Nationale Photovoltaik-Tagung, Bern (online), 29.-30. März 2022.
• Nussbaumer, H. et al. (2021) 'Comparative energy yield study of vertically installed bifacial PV modules measured by a miniturized test rig', in 38th European Photovoltaic Solar Energy Conference and Exhibition (EUPVSEC), online, 6-10 September 2021.
• Nussbaumer, H. (2019) 'PV Systeme mit bifazialen Modulen : Stand der Technik & Ausblick', in 17. Nationale Photovoltaik-Tagung 2019, Bern, 26.-27. März 2019.
• Klenk, M. et al. (2018) 'Bifacial modeling with the BIFOROT', in Fifth bifiPV Workshop, Denver, USA, 10-11 September 2018.
• Klenk, M. et al. (2017) 'BIFOROT – Experimental data for LCOE appraisal of bifacial systems', in 4th bifiPV Workshop 2017, Konstanz, Deutschland, 25-26 October 2017.
• Nussbaumer, H. (2017) 'Bifacial module concepts', in 4th bifiPV Workshop 2017, Konstanz, Deutschland, 25-26 October 2017.
• Klenk, M. et al. (2016) 'Bifacial outdoor roto tester : BIFOROT', in 3rd bifi PV 2016 Workshop on Bifacial PV, Miyazaki, Japan, 29-30 September 2016. Miyazaki: University of Miyazaki.

Publications before appointment at the ZHAW

• Juergen Schweckendiek, Ronald Hoyer, Sebastian Patzig-Klein, Franck Delahaye, Gerry Knoch, Hartmut Nussbaumer, "Cleaning in Crystalline Si Solar Cell Manufacturing", Solid State Phenomena, Vol. 195, pp. 283-288, 2013
• H. Nussbaumer, F. P. Baumgartner, G. Willeke and E. Bucher, „Hall mobility minimum in polycrystalline silicon“,Journal of Applied Physics 83, 292, 1998
• H. Nussbaumer, G. Willeke and E. Bucher, „Optical behavior of textured silicon“, J. Appl. Phys. 75, 1994, p. 2202
• H. Bender, J. Szlufcik, H. Nussbaumer, G. Palmers, O. Evrard, J. Nijs, R. Mertens, E. Bucher and G. Willeke, „Polycrystalline silicon solar cells with a mechanically formed texturization“, Appl. Phys. Lett. 62, 1993, p. 2941
• P. T. Landsberg, H. Nussbaumer and G. Willeke, „Band-band impact ionization and solar cell efficiency“, J. Appl. Phys. 74, 1993, p. 1451
• G. Willeke, H. Nussbaumer, H. Bender and E. Bucher, „A simple effective light trapping technique for polycrystalline silicon solar cells“, Solar Energy Materials and Solar Cells, 26, 1992, p. 345
• D. Pysch, B. Latzel, C. Schmitt, B.-U. Sander, S. Patzig-Klein, R. Sastrawan, J. Horzel, O. Voigt, A. Heeren & H. Nussbaumer,”Route to 19% Efficient Industrial Production Multi-Crystalline PERC Solar Cells Including a Fast ALD Al2O3 for Rear Side Passivation”, Proceedings to the 29th EU PVSEC 2014, Amsterdam
• S. Patzig-Klein, S. Xu ,L. Zanger, J. Wu, B. Zhou, M. Schumann, F. Delahaye, J. Schweckendiek, R. Dechant-Wagner, R. Sastrawan, A. Heeren and H. Nussbaumer, “Advanced processing sequences for diamond wire sawn silicon substrates”, Proceedings to the 28th European Solar Energy Conference 2013, Paris, p. 1761
• J. Horzel, N. Bay, T. Knarozovski, A. Träger, M. Passig, J. Burschik, M. Sieber, A. Hoffmann, B. Latzel, D. Pysch, C. Schmitt, R. Sastrawan, H.H. Kuehnlein, K. Vosteen, H. Nussbaumer, R. Boehme, H. Schillinger, A. Letize, B. Lee, T. Soederstroem, “Different Concepts of Implementing a Directly Plated Front Side Metallization into Industrial Solar Cell Mass Production” Proceedings to the 28th European Solar Energy Conference 2013, Paris, p. 1374
• A. Spribille, E. Lohmüller, B. Thaidigsmann, R. Hamid, H. Nussbaumer, F. Clement, R. Preu , “Wet Chemical Single-Side Emitter Etch Back for MWT Solar Cells with Al-BSF and Challenges for via Paste Selection”, Proceedings to the 28th European Solar Energy Conference 2013, Paris, p. 1080
• R. Sastrawan, D. Pysch, M. Bijker, F. Delahaye, B. Dielissen, W. Eipert, X. Gay, R. Görtzen, A. Hoffmann, B. Latzel, M. Lenes, X. Mao, S. Patzig-Klein, X. Qu, B.-U. Sander, C. Schmitt, F.M.M. Souren, A. Träger, K. Weise, S. Yang, H. Nussbaumer, “Implementation of a Multicrystalline ALD-Al2O3-PERC Technology into an Industrial Pilot Production”, Proceedings to the 28th European Solar Energy Conference 2013, Paris, p. 1861
• S. Patzig-Klein, E. Wefringhaus, C. Klein, W. Benko, F. Delahaye, S. Queißer, J. Schweckendiek 1, H. Nussbaumer, “ Overview of wet chemical texturing processes for “cast-mono” silicon materials”, Proceedings to the 27th European Solar Energy Conference, 2012, p.766
• R. Sastrawan, F. Aigner, A. Becker, R. Böhme, F. Delahaye, A. Hoffmann, A. Heeren, D. Kray, B. Latzel, D. Pysch, J. Rentsch, W. Saule, C. Schmitt, B. Straub, A. Träger, S. Queisser, Volk. A., L. Zanger, M. Zimmer and H. Nussbaumer, “Combing Laser Doping and Wet Chemical Etch Back for Industrial Selective Emitter Solar Cells”, Proceedings to the 27th European Solar Energy Conference, 2012, p.1563
• E. Cornagliotti, A Uruena, J. Horzel, J. John, L. Tous, D. Hendrickx, V. Prajapati, S. Singh, R. Hoyer, F. Delahaye, K. Weise, D. Queisser, H. Nussbaumer and J. Poortmans, “How Much Rear Side Polishing Is Required? A Study on the Impact of Rear Side Polishing in PERC Solar Cells”, Proceedings to the 27th European Solar Energy Conference, 2012, p. 561
• D. Kray, N. Bay, G.Cimiotti, N. Fritz, M. Glatthaar, S. Kleinschmidt, A. Lösel, O. Lühn, J. Schramm-Moura, A. Rodofili, A. Träger, H. Kühnlein, H. Nussbaumer, “Reducing Ag Cost and Increasing Efficiency. Multicrystalline Silicon Solar Cells with Direct Plated Contacts Exceeding 17% Efficiency”, Proceedings to the 26th European Solar Energy Conference, 2011, p. 1199
• N. Bay, J. Burschik, G.Cimiotti, N. Fritz, S. Kleinschmidt, M. Sieber, D. Kray,O. Lühn, H. H. Kühnlein, H. Nussbaumer, “Influence of Pretreatment Chemistry on the Performance of Direct Plated Silicon Solar Cells”, Proceedings to the 26th European Solar Energy Conference, 2011, p. 1659
• D. Kray, N. Bay, G. Cimiotti, S. Kleinschmidt, N. Kösterke, A. Lösel, M. Sailer, A. Träger, H. Kühnlein,H. Nussbaumer, C. Fleischmann, F. Granek, “Industrial LCP Selective Emitter Solar Cells With Plated Contacts”, Proceedings to the 35th World Solar Energy Conference, 2010, Honolulu, USA
• N. Bay, J. Burschik, G. Cimiotti, N. Fritz, N. Kösterke, D. Kray, A. Lösel, O. Lühn, M. Sieber, A. Träger, H. H. Kühnlein, H. Nussbaumer, “Adhesive One Step Ni/Ag and Ni/Cu/Ag Inline Direct Plating on Laser Processed Selective Emitter Structures”, Proceedings of the 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 2010, Valencia, Spain, p. 2183
• D. Kray, N. Bay, G. Cimiotti, S. Kleinschmidt, N. Kösterke, A. Lösel, O. Lühn, M. Sailer, A. Träger, H. Kühnlein, H. Nussbaumer, A. Fell, C. Fleischmann, S. Hopman, K. Mayer, M. Mesec, A. Rodofili, F. Granek, S.W. Glunz, E. Müller, P. Sempere, A. Pauchard, B. Richerzhagen, “High-Efficiency Large Area Industrial LCP Selective Emitter Solar Cells Ready for Production”, Proceedings of the 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 2010, Valencia, Spain, p. 1896
• E.M. Sachs, A.M. Gabor, P. Madden, S. Olibet, H. Gates, A. Ersen, V. Tarasov, D. Harris, K. Passino, F. van Mierlo, S. Queisser, A. Heeren, H. Kühnlein, F. Delahaye, H. Nussbaumer, “1366-Texture and 1366-Metallization: Superior Light Trapping and 30-Micron Fingers for Any Silicon Wafer Type at Low Cost” Proceedings of the 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 2010, Valencia, Spain, p. 1475
• H.H. Kuehnlein, N. Koesterke1, G. Cimiotti, E. Hartmannsgruber, N. Buerger, H. Nussbaumer, D. Luetke-Notarp, M. Becker, “>0.4% Absolut Efficiency Gain by Fast Ni-Cu-Sn Electroplating of Solar Cells with Fine Line Printed Contacts by a Single Side Wet Treatment Technology”, Proceedings to the 24th European Solar Energy Conference, , 2009, Hamburg, Germany, p. 282
• H. Nussbaumer, F. Delahaye, W. Saule, D. Nagel, S. Queisser, B. U. Sander, H. Kühnlein, N. Kösterke, N. Bay, G. Cimiotti, A. Eljaouhari, J. Schweckendiek, R. Dechant-Wagner, I. Sen, S. Kleinschmidt, “Wet Chemical Processing in Crystalline Silicon Wafer and Cell Production Today and Tomorrow”, Proceedings to the 24th European Solar Energy Conference, 2009, Hamburg, Germany, p. 1356
• H.H. Kuehnlein, N. Koesterke, G. Cimiotti, N. Bay, H. Nussbaumer, A. Pauchard, B. Richerzhagen, F. Granek, C. Fleischmann, S. Hopman, K. Mayer, M. Mesec, “Next Generation of Front Grid Metallization: LCP Selective Emitter Combined with Ni-Cu-Sn Direct Plating on Silicon”, Proceedings to the 24th European Solar Energy Conference, 2009, Hamburg, Germany, p. 1712
• J. Krümberg, I. Melnyk, M. Schmidt, M. Michel, T. Fidler, M. Kagerer, P. Fath, L. Heiliger and H. Nussbaumer, “New Innovative Alkaline Texturing Process for CZ Silicon Wafers”, Proceedings to the 24th European Solar Energy Conference, , 21-25 September 2009, Hamburg, Germany, p. 1748

go back