@inproceedings{HahneHerrmannRheinlaender1997,
  author    = {Hahne, E. and Herrmann, Ulf and Rheinl{\"a}nder, J.},
  title     = {The Effect of Tilt on Flow Pattern of Water/Steam Flow Through Heated Tubes},
  series = {Experimental heat transfer, fluid mechanics and thermodynamics 1997 : proceedings of the 4th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, Brussels, June 2 - 6, 1997. - Vol. 2},
  booktitle = {Experimental heat transfer, fluid mechanics and thermodynamics 1997 : proceedings of the 4th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, Brussels, June 2 - 6, 1997. - Vol. 2},
  editor    = {Girot, Michel},
  publisher = {Ed. ETS},
  address   = {Pisa},
  isbn      = {88-467-0014-7},
  pages     = {925 -- 934},
  year      = {1997},
  language  = {en}
}
@inproceedings{HerrmannRheinlaenderLippke1997,
  author    = {Herrmann, Ulf and Rheinl{\"a}nder, J. and Lippke, F.},
  title     = {Solar Fields for Direct Steam Generation in Parabolic Trough Collectors},
  series = {Components, tools, facilities and measurement techniques. - (Solar thermal concentrating technologies : proceedings of the 8th international symposium, October, 6 - 11, 1996, K{\"o}ln, Germany ; Vol. 2)},
  booktitle = {Components, tools, facilities and measurement techniques. - (Solar thermal concentrating technologies : proceedings of the 8th international symposium, October, 6 - 11, 1996, K{\"o}ln, Germany ; Vol. 2)},
  editor    = {Becker, Manfred},
  publisher = {M{\"u}ller},
  address   = {Heidelberg},
  isbn      = {3-7880-7616-X},
  pages     = {815 -- 834},
  year      = {1997},
  language  = {en}
}
@article{HerrmannLippke1999,
  author    = {Herrmann, Ulf and Lippke, F.},
  title     = {The influence of transients on the design of DSG solar fields},
  series = {Journal de Physique IV : proceedings},
  volume    = {9},
  journal   = {Journal de Physique IV : proceedings},
  number    = {PR3},
  isbn      = {2-86883-402-7},
  issn      = {1764-7177 (Online)},
  doi       = {10.1051/jp4:1999377},
  pages     = {489 -- 494},
  year      = {1999},
  language  = {en}
}
@inproceedings{KellyHerrmannHale2001,
  author    = {Kelly, Bruce and Herrmann, Ulf and Hale, M.-J.},
  title     = {Optimization Studies for Integrated Solar Combined Cycle Systems},
  series = {Solar engineering 2001 : proceedings of the International Solar Energy Conference ; presented at the 2001 International Solar Energy Conference, a part of Forum 2001 - Solar energy: the power to choose, April 21 - 25, 2001, Washington, D.C.},
  booktitle = {Solar engineering 2001 : proceedings of the International Solar Energy Conference ; presented at the 2001 International Solar Energy Conference, a part of Forum 2001 - Solar energy: the power to choose, April 21 - 25, 2001, Washington, D.C.},
  publisher = {ASME},
  address   = {New York, NY},
  isbn      = {0-7918-1670-2},
  pages     = {393 -- 398},
  year      = {2001},
  language  = {en}
}
@article{HerrmannKearney2002,
  author    = {Herrmann, Ulf and Kearney, David W.},
  title     = {Survey of Thermal Energy Storage for Parabolic Trough Power Plants},
  series = {Journal of Solar Energy Engineering},
  volume    = {124},
  journal   = {Journal of Solar Energy Engineering},
  number    = {2},
  issn      = {1528-8986 (Online)},
  doi       = {10.1115/1.1467601},
  pages     = {145 -- 152},
  year      = {2002},
  language  = {en}
}
@article{HerrmannKellyPrice2002,
  author    = {Herrmann, Ulf and Kelly, Bruce and Price, Henry},
  title     = {Two Tank Molten Salt Storage for Parabolic Trough Solar Power Plants},
  series = {Energy : the international journal},
  volume    = {29},
  journal   = {Energy : the international journal},
  number    = {5-6 (Special Issue SolarPaces)},
  issn      = {0360-5442},
  doi       = {10.1016/S0360-5442(03)00193-2},
  pages     = {883 -- 893},
  year      = {2002},
  language  = {en}
}
@article{KearneyKellyHerrmannetal.2002,
  author    = {Kearney, David W. and Kelly, Bruce and Herrmann, Ulf and Cable, R. and Pacheco, J. and Mahoney, R. and Price, Henry and Blake, D. and Nava, P. and Potrovitza, N.},
  title     = {Engineering Aspects of a Molten Salt Heat Transfer Fluid in a Trough Solar Field},
  series = {Energy : the international journal},
  volume    = {29},
  journal   = {Energy : the international journal},
  number    = {5-6 (Special Issue SolarPaces)},
  issn      = {0360-5442},
  doi       = {10.1016/S0360-5442(03)00191-9},
  pages     = {861 -- 870},
  year      = {2002},
  language  = {en}
}
@inproceedings{DerschGeyerHerrmannetal.2002,
  author    = {Dersch, J{\"u}rgen and Geyer, Michael and Herrmann, Ulf and Jones, Scott A. and Kelly, Bruce and Kistner, Rainer and Ortmanns, Winfried and Pitz-Paal, Robert and Price, Henry},
  title     = {Trough integration into power plants : a study on the performance and economy of integrated solar combined cycle systems},
  series = {Proceedings of the 11th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies : September 4 - 6, 2002, Zurich, Switzerland / Paul Scherrer Institut, PSI; ETH, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich},
  booktitle = {Proceedings of the 11th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies : September 4 - 6, 2002, Zurich, Switzerland / Paul Scherrer Institut, PSI; ETH, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich},
  editor    = {Steinfeld, Aldo},
  publisher = {Paul Scherrer Inst.},
  address   = {Villingen},
  isbn      = {3-9521409-3-7},
  pages     = {661 -- 671},
  year      = {2002},
  language  = {en}
}
@inproceedings{HerrmannKellyPrice2002,
  author    = {Herrmann, Ulf and Kelly, Bruce and Price, Henry},
  title     = {Two Tank Molten Salt Storage for Parabolic Trough Solar Power Plants},
  series = {Proceedings of the 11th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies : September 4 - 6, 2002, Zurich, Switzerland / Paul Scherrer Institut, PSI; ETH, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich},
  booktitle = {Proceedings of the 11th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies : September 4 - 6, 2002, Zurich, Switzerland / Paul Scherrer Institut, PSI; ETH, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich},
  editor    = {Steinfeld, Aldo},
  publisher = {Paul Scherrer Inst.},
  address   = {Villingen},
  isbn      = {3-9521409-3-7},
  pages     = {517 -- 524},
  year      = {2002},
  language  = {en}
}
@inproceedings{DerschGeyerHerrmannetal.2002,
  author    = {Dersch, J{\"u}rgen and Geyer, Michael and Herrmann, Ulf and Jones, Scott A. and Kelly, Bruce and Kistner, Rainer and Ortmanns, Winfried and Pitz-Paal, Robert and Price, Henry},
  title     = {Solar Trough Integration Into Combined Cycle Systems},
  series = {Solar engineering 2002 : proceedings of the International Solar Energy Conference ; presented at the 2002 International Solar Energy Conference, a part of Solar 2002 - Sunrise on the Reliable Energy Economy, June 15 - 20, 2002, Reno, Nevada},
  booktitle = {Solar engineering 2002 : proceedings of the International Solar Energy Conference ; presented at the 2002 International Solar Energy Conference, a part of Solar 2002 - Sunrise on the Reliable Energy Economy, June 15 - 20, 2002, Reno, Nevada},
  editor    = {Pearson, J. Boise},
  publisher = {ASME},
  isbn      = {0-7918-1689-3},
  doi       = {doi:10.1115/SED2002-1072},
  pages     = {351 -- 359},
  year      = {2002},
  language  = {en}
}
@inproceedings{AringhoffGeyerHerrmannetal.2002,
  author    = {Aringhoff, R. and Geyer, Michael and Herrmann, Ulf and Kistner, Rainer and Nava, P. and Osuna, R.},
  title     = {AndaSol : 50MW Solar Plants with 9 Hour Storage for Southern Spain},
  series = {Proceedings of the 11th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies : September 4 - 6, 2002, Zurich, Switzerland / Paul Scherrer Institut, PSI; ETH, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich},
  booktitle = {Proceedings of the 11th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies : September 4 - 6, 2002, Zurich, Switzerland / Paul Scherrer Institut, PSI; ETH, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich},
  editor    = {Steinfeld, Aldo},
  publisher = {Paul Scherrer Inst.},
  address   = {Villingen},
  isbn      = {3-9521409-3-7},
  pages     = {37 -- 42},
  year      = {2002},
  language  = {en}
}
@article{KearneyHerrmannNavaetal.2003,
  author    = {Kearney, D. and Herrmann, Ulf and Nava, P. and Kelly, B. and Mahoney, R. and Pacheco, J. and Cable, R. and Potrovitza, N. and Blake, D. and Price, H.},
  title     = {Assessment of a Molten Salt Heat Transfer Fluid in a Parabolic Trough Solar Field},
  series = {Journal of Solar Energy Engineering},
  volume    = {125},
  journal   = {Journal of Solar Energy Engineering},
  number    = {2},
  issn      = {1528-8986},
  doi       = {10.1115/1.1565087},
  pages     = {170 -- 176},
  year      = {2003},
  language  = {en}
}
@article{DerschGeyerHerrmannetal.2004,
  author    = {Dersch, J{\"u}rgen and Geyer, Michael and Herrmann, Ulf and Jones, Scott A. and Kelly, Bruce and Kistner, Rainer and Ortmanns, Winfried and Pitz-Paal, Robert and Price, Henry},
  title     = {Trough integration into power plants—a study on the performance and economy of integrated solar combined cycle systems},
  series = {Energy : the international journal},
  volume    = {29},
  journal   = {Energy : the international journal},
  number    = {5-6 (Special Issue SolarPaces)},
  issn      = {0360-5442},
  doi       = {10.1016/S0360-5442(03)00199-3},
  pages     = {947 -- 959},
  year      = {2004},
  language  = {en}
}
@inproceedings{HerrmannGraeterNava2004,
  author    = {Herrmann, Ulf and Graeter, F. and Nava, P.},
  title     = {Performance of the SKAL-ET Collector Loop at KJC Operating Company},
  series = {12th International Symposium Solar Power and Chemical Energy Systems, October 6-8, 2004, Oaxaca Mexico ; SolarPACES International Symposium, 12},
  booktitle = {12th International Symposium Solar Power and Chemical Energy Systems, October 6-8, 2004, Oaxaca Mexico ; SolarPACES International Symposium, 12},
  editor    = {Ramos, C.},
  publisher = {Instituto de Investigaciones Electricas},
  address   = {[s.l.]},
  isbn      = {968-6114-18-1},
  year      = {2004},
  language  = {en}
}
@inproceedings{LuepfertHerrmannPriceetal.2004,
  author    = {L{\"u}pfert, E. and Herrmann, Ulf and Price, Henry and Zarza, E. and Kistener, R.},
  title     = {Towards Standard Performance Analysis for Parabolic Trough Collector Fields},
  series = {12th International Symposium Solar Power and Chemical Energy Systems, October 6-8, 2004, Oaxaca Mexico ; SolarPACES International Symposium, 12},
  booktitle = {12th International Symposium Solar Power and Chemical Energy Systems, October 6-8, 2004, Oaxaca Mexico ; SolarPACES International Symposium, 12},
  editor    = {Ramos, C.},
  publisher = {Instituto de Investigaciones Electricas},
  address   = {[s.l.]},
  isbn      = {968-6114-18-1},
  year      = {2004},
  language  = {en}
}
@phdthesis{Herrmann2004,
  author    = {Herrmann, Ulf},
  title     = {Untersuchungen zur Rohrwandbenetzung bei der Dampferzeugung in horizontalen und geneigten Parabolrinnen-Solarkollektoren. - (FLAGSOL Forschungsbericht)},
  publisher = {FLAGSOL},
  address   = {K{\"o}ln},
  isbn      = {3-9804901-2-2},
  pages     = {IX, 145 S. : Ill., graph. Darst.},
  year      = {2004},
  language  = {de}
}
@article{HerrmannNava2005,
  author    = {Herrmann, Ulf and Nava, P.},
  title     = {Die Strahlung der Sonne einfangen},
  series = {DLR-Nachrichten / Deutsches Zentrum f{\"u}r Luft- und Raumfahrt},
  volume    = {109},
  journal   = {DLR-Nachrichten / Deutsches Zentrum f{\"u}r Luft- und Raumfahrt},
  number    = {Sonderheft Solarforschung},
  issn      = {0937-0420},
  pages     = {34 -- 37},
  year      = {2005},
  language  = {de}
}
@inproceedings{HerrmannWorringerGraeteretal.2006,
  author    = {Herrmann, Ulf and Worringer, S. and Graeter, F. and Nava, P.},
  title     = {Three Years of Operation Experience of the SKAL-ET Collector Loop at SEGS V},
  series = {13th International Symposium Concentrated Solar Power and Chemical Energy Technologies, June 20 - 23, 2006, Seville, Spain},
  booktitle = {13th International Symposium Concentrated Solar Power and Chemical Energy Technologies, June 20 - 23, 2006, Seville, Spain},
  editor    = {Romero, Manuel},
  publisher = {SolarPACES [u.a.]},
  address   = {[s.l.]},
  isbn      = {84-7834-519-1},
  pages     = {1 CD-ROM},
  year      = {2006},
  language  = {en}
}
@inproceedings{HerrmannVorbruggNava2009,
  author    = {Herrmann, Ulf and Vorbrugg, O. and Nava, P.},
  title     = {Construction and Commissioning Process of the Andasol Solar Field},
  series = {SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings},
  booktitle = {SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings},
  publisher = {Deutsches Zentrum f{\"u}r Luft- u. Raumfahrt},
  address   = {Stuttgart},
  isbn      = {978-3-00-028755-8},
  pages     = {1 CD-ROM},
  year      = {2009},
  language  = {en}
}
@inproceedings{SchulteFischedickTammeHerrmann2009,
  author    = {Schulte-Fischedick, Jan and Tamme, Rainer and Herrmann, Ulf},
  title     = {CFD Analysis of the Cool Down Behaviour of Molten Salt Thermal Storage Systems},
  series = {ASME 2008 2nd International Conference on Energy Sustainability collocated with the Heat Transfer, Fluids Engineering, and 3rd Energy Nanotechnology Conferences, ASME 2008 2nd International Conference on Energy Sustainability, Jacksonville, Florida, USA, August 10-14, 2008. - Vol. 2},
  booktitle = {ASME 2008 2nd International Conference on Energy Sustainability collocated with the Heat Transfer, Fluids Engineering, and 3rd Energy Nanotechnology Conferences, ASME 2008 2nd International Conference on Energy Sustainability, Jacksonville, Florida, USA, August 10-14, 2008. - Vol. 2},
  publisher = {ASME},
  address   = {New York, NY},
  isbn      = {978-0-7918-4320-8},
  doi       = {doi:10.1115/ES2008-54101},
  pages     = {515 -- 524},
  year      = {2009},
  language  = {de}
}
@inproceedings{AnthrakidisHerrmannMirzaetal.2014,
  author    = {Anthrakidis, Anette and Herrmann, Ulf and Mirza, M. F. and Schorn, Christian and Schwarzer, Klemens and Wedding, Philipp and Weis, Fabian},
  title     = {Parabolrinnenentwicklung und Qualifizierung am Solar-Institut J{\"u}lich},
  series = {Thermische Solarenergie : 24. Symposium ; 7. bis 9. Mai 2014, Kloster Banz, Bad Staffelstein},
  booktitle = {Thermische Solarenergie : 24. Symposium ; 7. bis 9. Mai 2014, Kloster Banz, Bad Staffelstein},
  publisher = {OTTI},
  address   = {Regensburg},
  organization    = {Ostbayerisches Technologie-Transfer-Institut},
  isbn      = {978-3-943891-35-5},
  pages     = {242 -- 243},
  year      = {2014},
  language  = {de}
}
@inproceedings{JanotteFecklerKoetteretal.2014,
  author    = {Janotte, N. and Feckler, G. and K{\"o}tter, Jens and Decker, Stefan and Herrmann, Ulf and Schmitz, Mark and L{\"u}pfert, E.},
  title     = {Dynamic performance evaluation of the HelioTrough® collector demonstration loop : towards a new benchmark in parabolic trough qualification},
  series = {SolarPACES International Conference 2013, Las Vegas, Nevada, USA, 17 - 20 September 2013 : [proceedings]. - Pt. 1. - (Energy procedia ; 49)},
  booktitle = {SolarPACES International Conference 2013, Las Vegas, Nevada, USA, 17 - 20 September 2013 : [proceedings]. - Pt. 1. - (Energy procedia ; 49)},
  publisher = {Curran},
  address   = {Red Hook, NY},
  isbn      = {978-1-63266-904-9},
  issn      = {1876-6102},
  doi       = {10.1016/j.egypro.2014.03.012},
  pages     = {109 -- 117},
  year      = {2014},
  language  = {en}
}
@inproceedings{AnthrakidisHerrmannSchornetal.2015,
  author    = {Anthrakidis, Anette and Herrmann, Ulf and Schorn, Christian and Schwarzer, Klemens and Wedding, Philipp and Weis, Fabian},
  title     = {Development and Testing of a Novel Method for the Determination of the Efficiency of Concentrating Solar Thermal Collectors},
  series = {Conference Proceedings Solar World Congress 2015, Daegu, Korea, 08 - 12 November 2015},
  booktitle = {Conference Proceedings Solar World Congress 2015, Daegu, Korea, 08 - 12 November 2015},
  pages     = {9 Seiten},
  year      = {2015},
  language  = {en}
}
@inproceedings{AnthrakidisHerrmannSchornetal.2015,
  author    = {Anthrakidis, Anette and Herrmann, Ulf and Schorn, Christian and Schwarzer, Klemens and Wedding, Philipp},
  title     = {Weiterentwicklung und Erprobung eines neuartigen Verfahrens zur Bestimmung der Effizienz von konzentrierenden solarthermischen Kollektoren},
  series = {25. OTTI Symposium Thermische Solarenergie},
  booktitle = {25. OTTI Symposium Thermische Solarenergie},
  pages     = {15 Seiten},
  year      = {2015},
  language  = {de}
}
@techreport{WeisSchornAnthrakidisetal.2016,
  author    = {Weis, Fabian and Schorn, Christian and Anthrakidis, Anette and Herrmann, Ulf},
  title     = {Entwicklung eines kleinen Parabolrinnenkollektors mit Kunststoffkorpus zur Bereitstellung solarer Prozessw{\"a}rme : Poly-P : Abschlussbericht},
  publisher = {Solar-Institut J{\"u}lich},
  address   = {J{\"u}lich},
  pages     = {56 Seiten},
  year      = {2016},
  language  = {de}
}
@inproceedings{TeixeiraBouraNiederwestbergMcLeodetal.2016,
  author    = {Teixeira Boura, Cristiano Jos{\´e} and Niederwestberg, Stefan and McLeod, Jacqueline and Herrmann, Ulf and Hoffschmidt, Bernhard},
  title     = {Development of heat exchanger for high temperature energy storage with bulk materials},
  series = {AIP Conference Proceedings},
  volume    = {1734},
  booktitle = {AIP Conference Proceedings},
  number    = {1},
  doi       = {10.1063/1.4949106},
  pages     = {050008-1 -- 050008-7},
  year      = {2016},
  language  = {en}
}
@inproceedings{SchornWeisAnthrakidisetal.2016,
  author    = {Schorn, Christian and Weis, Fabian and Anthrakidis, Anette and Schwarzer, Klemens and Schmitz, Mark and Herrmann, Ulf},
  title     = {Entwicklung und Bewertung eines Parabolrinnenkollektors zur Prozessw{\"a}rmebereitstellung},
  series = {26. Symposium Thermische Solarenergie, 20.-22.04.2016 in Bad Staffelstein},
  booktitle = {26. Symposium Thermische Solarenergie, 20.-22.04.2016 in Bad Staffelstein},
  pages     = {1 -- 13},
  year      = {2016},
  language  = {de}
}
@article{DammSauerbornFendetal.2017,
  author    = {Damm, Marc Andr{\´e} and Sauerborn, Markus and Fend, Thomas and Herrmann, Ulf},
  title     = {Optimisation of a urea selective catalytic reduction system with a coated ceramic mixing element},
  series = {Journal of ceramic science and technology},
  volume    = {8},
  journal   = {Journal of ceramic science and technology},
  number    = {1},
  publisher = {G{\"o}ller},
  address   = {Baden-Baden},
  isbn      = {2190-9385 (Print)},
  issn      = {2190-9385 (Online)},
  doi       = {10.4416/JCST2016-00056},
  pages     = {19 -- 24},
  year      = {2017},
  language  = {en}
}
@inproceedings{SauerbornLiebenstundRaueetal.2017,
  author    = {Sauerborn, Markus and Liebenstund, Lena and Raue, Markus and Mang, Thomas and Herrmann, Ulf and Dueing, Andreas},
  title     = {Analytic method for material aging and quality analyzing to forecast long time stability of plastic micro heliostat components},
  series = {AIP Conference Proceedings},
  volume    = {1850},
  booktitle = {AIP Conference Proceedings},
  number    = {1},
  doi       = {10.1063/1.4984388},
  pages     = {030045-1 -- 030045-8},
  year      = {2017},
  language  = {en}
}
@incollection{HerrmannKearneyRoegeretal.2017,
  author    = {Herrmann, Ulf and Kearney, D. and R{\"o}ger, M. and Prahl, C.},
  title     = {System performance measurements},
  series = {The Performance of Concentrated Solar Power (CSP) Systems : Modelling, Measurement and Assessment},
  booktitle = {The Performance of Concentrated Solar Power (CSP) Systems : Modelling, Measurement and Assessment},
  publisher = {Woodhead Publishing},
  address   = {Duxford},
  isbn      = {978-0-08-100448-7},
  doi       = {https://doi.org/10.1016/B978-0-08-100447-0.00005-5},
  pages     = {115 -- 165},
  year      = {2017},
  abstract  = {This chapter introduces performance and acceptance testing and describes state-of-the-art tools, methods, and instruments to assess the plant performance or realize plant acceptance testing. The status of the development of standards for performance assessment is given.},
  language  = {en}
}
@inproceedings{RendonDieckmannWeidleetal.2018,
  author    = {Rendon, Carlos and Dieckmann, Simon and Weidle, Mathias and Dersch, J{\"u}rgen and Teixeira Boura, Cristiano Jos{\´e} and Polklas, Thomas and Kuschel, Marcus and Herrmann, Ulf},
  title     = {Retrofitting of existing parabolic trough collector power plants with molten salt tower systems},
  series = {AIP Conference Proceedings},
  volume    = {2033},
  booktitle = {AIP Conference Proceedings},
  number    = {1},
  doi       = {10.1063/1.5067030},
  pages     = {030014-1 -- 030014-8},
  year      = {2018},
  language  = {en}
}
@inproceedings{BreitbachAlexopoulosMayetal.2019,
  author    = {Breitbach, Gerd and Alexopoulos, Spiros and May, Martin and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Analysis of volumetric solar radiation absorbers made of wire meshes},
  series = {AIP Conference Proceedings},
  volume    = {2126},
  booktitle = {AIP Conference Proceedings},
  issn      = {0094243X},
  doi       = {10.1063/1.5117521},
  pages     = {030009-1 -- 030009-6},
  year      = {2019},
  language  = {en}
}
@inproceedings{MahdiRendonSchwageretal.2019,
  author    = {Mahdi, Zahra and Rend{\´o}n, Carlos and Schwager, Christian and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Novel concept for indirect solar-heated methane reforming},
  series = {AIP Conference Proceedings},
  volume    = {2126},
  booktitle = {AIP Conference Proceedings},
  publisher = {AIP Publishing},
  address   = {Melville, NY},
  issn      = {0094-243X},
  doi       = {10.1063/1.5117694},
  pages     = {180014-1 -- 180014-7},
  year      = {2019},
  language  = {en}
}
@inproceedings{MayBreitbachAlexopoulosetal.2019,
  author    = {May, Martin and Breitbach, Gerd and Alexopoulos, Spiros and Latzke, Markus and B{\"a}umer, Klaus and Uhlig, Ralf and S{\"o}hn, Matthias and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Experimental facility for investigations of wire mesh absorbers for pressurized gases},
  series = {AIP Conference Proceedings},
  volume    = {2126},
  booktitle = {AIP Conference Proceedings},
  issn      = {0094243X},
  doi       = {10.1063/1.5117547},
  pages     = {030035-1 -- 030035-9},
  year      = {2019},
  language  = {en}
}
@inproceedings{SattlerAlexopoulosCaminosetal.2019,
  author    = {Sattler, Johannes, Christoph and Alexopoulos, Spiros and Caminos, Ricardo Alexander Chico and Mitchell, John C. and Ruiz, Victor C. and Kalogirou, Soteris and Ktistis, Panayiotis K. and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Dynamic simulation model of a parabolic trough collector system with concrete thermal energy storage for process steam generation},
  series = {AIP Conference Proceedings},
  volume    = {2126},
  booktitle = {AIP Conference Proceedings},
  issn      = {0094243X},
  doi       = {10.1063/1.5117663},
  pages     = {150007-1 -- 150007-8},
  year      = {2019},
  language  = {en}
}
@article{HerrmannSchwarzenbartDittmannGabriel2019,
  author    = {Herrmann, Ulf and Schwarzenbart, Marc and Dittmann-Gabriel, S{\"o}ren},
  title     = {Speicher statt Kohle. Integration thermischer Stromspeicher in vorhandene Kraftwerksstandorte},
  series = {BWK : Das Energie-Fachmagazin},
  volume    = {71},
  journal   = {BWK : Das Energie-Fachmagazin},
  number    = {4},
  publisher = {Springer-VDI-Verl.},
  address   = {D{\"u}sseldorf},
  issn      = {1436-4883},
  pages     = {42 -- 45},
  year      = {2019},
  language  = {de}
}
@inproceedings{SchwagerTeixeiraBouraFleschetal.2019,
  author    = {Schwager, Christian and Teixeira Boura, Cristiano Jos{\´e} and Flesch, Robert and Alexopoulos, Spiros and Herrmann, Ulf},
  title     = {Improved efficiency prediction of a molten salt receiver based on dynamic cloud passage simulation},
  series = {AIP Conference Proceedings},
  volume    = {2126},
  booktitle = {AIP Conference Proceedings},
  number    = {1},
  isbn      = {978-0-7354-1866-0},
  doi       = {10.1063/1.5117566},
  pages     = {030054-1 -- 030054-8},
  year      = {2019},
  language  = {en}
}
@article{HerrmannSchwarzenbartDittmannGabrieletal.2019,
  author    = {Herrmann, Ulf and Schwarzenbart, Marc and Dittmann-Gabriel, S{\"o}ren and May, Martin},
  title     = {Hochtemperatur-W{\"a}rmespeicher f{\"u}r die Strom- und W{\"a}rmewende},
  series = {Solarzeitalter : Politik, Kultur und {\"O}konomie erneuerbarer Energien},
  volume    = {31},
  journal   = {Solarzeitalter : Politik, Kultur und {\"O}konomie erneuerbarer Energien},
  number    = {2},
  issn      = {0937-3802},
  pages     = {18 -- 23},
  year      = {2019},
  language  = {de}
}
@article{MeyerHaenelBeehetal.2020,
  author    = {Meyer, S. and H{\"a}nel, Matthias and Beeh, B. and Dittmann-Gabriel, S{\"o}ren and Dluhosch, R. and May, Martin and Herrmann, Ulf and [und 5 weitere],},
  title     = {Multifunktionaler thermischer Stromspeicher f{\"u}r die Strom- und W{\"a}rmeversorgung der Industrie von morgen},
  series = {ETG Journal / Energietechnische Gesellschaft im VDE (ETG)},
  volume    = {2020},
  journal   = {ETG Journal / Energietechnische Gesellschaft im VDE (ETG)},
  number    = {1},
  issn      = {2625-9907},
  pages     = {6 -- 9},
  year      = {2020},
  language  = {de}
}
@inproceedings{SattlerChicoCaminosAttietal.2020,
  author    = {Sattler, Johannes Christoph and Chico Caminos, Ricardo Alexander and Atti, Vikrama Nagababu and {\"U}rlings, Nicolas and Dutta, Siddharth and Ruiz, Victor and Kalogirou, Soteris and Ktistis, Panayiotis and Agathokleous, Rafaela and Alexopoulos, Spiros and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Dynamic simulation tool for a performance evaluation and sensitivity study of a parabolic trough collector system with concrete thermal energy storage},
  series = {AIP Conference Proceedings 2303},
  booktitle = {AIP Conference Proceedings 2303},
  publisher = {American Institute of Physics},
  address   = {Melville, NY},
  issn      = {0094-243X},
  doi       = {10.1063/5.0029277},
  pages     = {160004},
  year      = {2020},
  language  = {de}
}
@inproceedings{SattlerCaminosUerlingsetal.2020,
  author    = {Sattler, Johannes, Christoph and Caminos, Ricardo Alexander Chico and {\"U}rlings, Nicolas and Dutta, Siddharth and Ruiz, Victor and Kalogirou, Soteris and Ktistis, Panayiotis and Agathokleous, Rafaela and Jung, Christian and Alexopoulos, Spiros and Atti, Vikrama Nagababu and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Operational experience and behaviour of a parabolic trough collector system with concrete thermal energy storage for process steam generation in Cyprus},
  series = {AIP Conference Proceedings},
  booktitle = {AIP Conference Proceedings},
  number    = {2303},
  doi       = {10.1063/5.0029278},
  pages     = {140004-1 -- 140004-10},
  year      = {2020},
  language  = {en}
}
@inproceedings{RendonSchwagerGhiasietal.2020,
  author    = {Rendon, Carlos and Schwager, Christian and Ghiasi, Mona and Schmitz, Pascal and Bohang, Fakhri and Caminos, Ricardo Alexander Chico and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Modeling and upscaling of a pilot bayonettube reactor for indirect solar mixed methane reforming},
  series = {AIP Conference Proceedings},
  booktitle = {AIP Conference Proceedings},
  number    = {2303},
  doi       = {10.1063/5.0029974},
  pages     = {170012-1 -- 170012-9},
  year      = {2020},
  language  = {en}
}
@inproceedings{DuranParedesMottaghyHerrmannetal.2020,
  author    = {Duran Paredes, Ludwin and Mottaghy, Darius and Herrmann, Ulf and Groß, Rolf Fritz},
  title     = {Online ground temperature and soil moisture monitoring of a shallow geothermal system with non-conventional components},
  series = {EGU General Assembly 2020},
  booktitle = {EGU General Assembly 2020},
  year      = {2020},
  abstract  = {We present first results from a newly developed monitoring station for a closed loop geothermal heat pump test installation at our campus, consisting of helix coils and plate heat exchangers, as well as an ice-store system. There are more than 40 temperature sensors and several soil moisture content sensors distributed around the system, allowing a detailed monitoring under different operating conditions.In the view of the modern development of renewable energies along with the newly concepts known as Internet of Things and Industry 4.0 (high-tech strategy from the German government), we created a user-friendly web application, which will connect the things (sensors) with the open network (www). Besides other advantages, this allows a continuous remote monitoring of the data from the numerous sensors at an arbitrary sampling rate.Based on the recorded data, we will also present first results from numerical simulations, taking into account all relevant heat transport processes.The aim is to improve the understanding of these processes and their influence on the thermal behavior of shallow geothermal systems in the unsaturated zone. This will in turn facilitate the prediction of the performance of these systems and therefore yield an improvement in their dimensioning when designing a specific shallow geothermal installation.},
  language  = {en}
}
@inproceedings{NeumannAdamBackesetal.2021,
  author    = {Neumann, Hannah and Adam, Mario and Backes, Klaus and B{\"o}rner, Martin and Clees, Tanja and Doetsch, Christian and Glaeser, Susanne and Herrmann, Ulf and May, Johanna and Rosenthal, Florian and Sauer, Dirk Uwe and Stadler, Ingo},
  title     = {Development of open educational resources for renewable energy and the energy transition process},
  series = {ISES SWC 2021},
  booktitle = {ISES SWC 2021},
  publisher = {International Solar Energy Society},
  address   = {Freiburg},
  doi       = {10.18086/swc.2021.47.03},
  pages     = {6 Seiten},
  year      = {2021},
  abstract  = {The dissemination of knowledge about renewable energies is understood as a social task with the highest topicality. The transfer of teaching content on renewable energies into digital open educational resources offers the opportunity to significantly accelerate the implementation of the energy transition. Thus, in the here presented project six German universities create open educational resources for the energy transition. These materials are available to the public on the internet under a free license. So far there has been no publicly accessible, editable media that cover entire learning units about renewable energies extensively and in high technical quality. Thus, in this project, the content that remains up-to-date for a longer period is appropriately prepared in terms of media didactics. The materials enable lecturers to provide students with in-depth training about technologies for the energy transition. In a particular way, the created material is also suitable for making the general public knowledgeable about the energy transition with scientifically based material.},
  language  = {en}
}
@article{SchwagerFleschSchwarzboezletal.2022,
  author    = {Schwager, Christian and Flesch, Robert and Schwarzb{\"o}zl, Peter and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e}},
  title     = {Advanced two phase flow model for transient molten salt receiver system simulation},
  series = {Solar Energy},
  volume    = {232},
  journal   = {Solar Energy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0038-092X (print)},
  doi       = {10.1016/j.solener.2021.12.065},
  pages     = {362 -- 375},
  year      = {2022},
  abstract  = {In order to realistically predict and optimize the actual performance of a concentrating solar power (CSP) plant sophisticated simulation models and methods are required. This paper presents a detailed dynamic simulation model for a Molten Salt Solar Tower (MST) system, which is capable of simulating transient operation including detailed startup and shutdown procedures including drainage and refill. For appropriate representation of the transient behavior of the receiver as well as replication of local bulk and surface temperatures a discretized receiver model based on a novel homogeneous two-phase (2P) flow modelling approach is implemented in Modelica Dymola®. This allows for reasonable representation of the very different hydraulic and thermal properties of molten salt versus air as well as the transition between both. This dynamic 2P receiver model is embedded in a comprehensive one-dimensional model of a commercial scale MST system and coupled with a transient receiver flux density distribution from raytracing based heliostat field simulation. This enables for detailed process prediction with reasonable computational effort, while providing data such as local salt film and wall temperatures, realistic control behavior as well as net performance of the overall system. Besides a model description, this paper presents some results of a validation as well as the simulation of a complete startup procedure. Finally, a study on numerical simulation performance and grid dependencies is presented and discussed.},
  language  = {en}
}
@inproceedings{GedleSchmitzGielenetal.2022,
  author    = {Gedle, Yibekal and Schmitz, Mark and Gielen, Hans and Schmitz, Pascal and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e} and Mahdi, Zahra and Caminos, Ricardo Alexander Chico and Dersch, J{\"u}rgen},
  title     = {Analysis of an integrated CSP-PV hybrid power plant},
  series = {SolarPACES 2020},
  booktitle = {SolarPACES 2020},
  number    = {2445 / 1},
  publisher = {AIP conference proceedings / American Institute of Physics},
  address   = {Melville, NY},
  isbn      = {978-0-7354-4195-8},
  issn      = {1551-7616 (online)},
  doi       = {10.1063/5.0086236},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {In the past, CSP and PV have been seen as competing technologies. Despite massive reductions in the electricity generation costs of CSP plants, PV power generation is - at least during sunshine hours - significantly cheaper. If electricity is required not only during the daytime, but around the clock, CSP with its inherent thermal energy storage gets an advantage in terms of LEC. There are a few examples of projects in which CSP plants and PV plants have been co-located, meaning that they feed into the same grid connection point and ideally optimize their operation strategy to yield an overall benefit. In the past eight years, TSK Flagsol has developed a plant concept, which merges both solar technologies into one highly Integrated CSP-PV-Hybrid (ICPH) power plant. Here, unlike in simply co-located concepts, as analyzed e.g. in [1] - [4], excess PV power that would have to be dumped is used in electric molten salt heaters to increase the storage temperature, improving storage and conversion efficiency. The authors demonstrate the electricity cost sensitivity to subsystem sizing for various market scenarios, and compare the resulting optimized ICPH plants with co-located hybrid plants. Independent of the three feed-in tariffs that have been assumed, the ICPH plant shows an electricity cost advantage of almost 20\% while maintaining a high degree of flexibility in power dispatch as it is characteristic for CSP power plants. As all components of such an innovative concept are well proven, the system is ready for commercial market implementation. A first project is already contracted and in early engineering execution.},
  language  = {en}
}
@inproceedings{MahdiDerschSchmitzetal.2022,
  author    = {Mahdi, Zahra and Dersch, J{\"u}rgen and Schmitz, Pascal and Dieckmann, Simon and Caminos, Ricardo Alexander Chico and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf and Schwager, Christian and Schmitz, Mark and Gielen, Hans and Gedle, Yibekal and B{\"u}scher, Rauno},
  title     = {Technical assessment of Brayton cycle heat pumps for the integration in hybrid PV-CSP power plants},
  series = {SOLARPACES 2020},
  booktitle = {SOLARPACES 2020},
  number    = {2445 / 1},
  publisher = {AIP conference proceedings / American Institute of Physics},
  address   = {Melville, NY},
  isbn      = {978-0-7354-4195-8},
  issn      = {1551-7616 (online)},
  doi       = {10.1063/5.0086269},
  pages     = {11 Seiten},
  year      = {2022},
  abstract  = {The hybridization of Concentrated Solar Power (CSP) and Photovoltaics (PV) systems is a promising approach to reduce costs of solar power plants, while increasing dispatchability and flexibility of power generation. High temperature heat pumps (HT HP) can be utilized to boost the salt temperature in the thermal energy storage (TES) of a Parabolic Trough Collector (PTC) system from 385 °C up to 565 °C. A PV field can supply the power for the HT HP, thus effectively storing the PV power as thermal energy. Besides cost-efficiently storing energy from the PV field, the power block efficiency of the overall system is improved due to the higher steam parameters. This paper presents a technical assessment of Brayton cycle heat pumps to be integrated in hybrid PV-CSP power plants. As a first step, a theoretical analysis was carried out to find the most suitable working fluid. The analysis included the fluids Air, Argon (Ar), Nitrogen (N2) and Carbon dioxide (CO2). N2 has been chosen as the optimal working fluid for the system. After the selection of the ideal working medium, different concepts for the arrangement of a HT HP in a PV-CSP hybrid power plant were developed and simulated in EBSILON®Professional. The concepts were evaluated technically by comparing the number of components required, pressure losses and coefficient of performance (COP).},
  language  = {en}
}
@inproceedings{ZahraPhaniSrujanCaminosetal.2022,
  author    = {Zahra, Mahdi and Phani Srujan, Merige and Caminos, Ricardo Alexander Chico and Schmitz, Pascal and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e} and Schmitz, Mark and Gielen, Hans and Gedle, Yibekal and Dersch, J{\"u}rgen},
  title     = {Modeling the thermal behavior of solar salt in electrical resistance heaters for the application in PV-CSP hybrid power plants},
  series = {SOLARPACES 2020},
  booktitle = {SOLARPACES 2020},
  number    = {2445 / 1},
  publisher = {AIP conference proceedings / American Institute of Physics},
  address   = {Melville, NY},
  isbn      = {978-0-7354-4195-8},
  issn      = {1551-7616 (online)},
  doi       = {10.1063/5.0086268},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {Concentrated Solar Power (CSP) systems are able to store energy cost-effectively in their integrated thermal energy storage (TES). By intelligently combining Photovoltaics (PV) systems with CSP, a further cost reduction of solar power plants is expected, as well as an increase in dispatchability and flexibility of power generation. PV-powered Resistance Heaters (RH) can be deployed to raise the temperature of the molten salt hot storage from 385 °C up to 565 °C in a Parabolic Trough Collector (PTC) plant. To avoid freezing and decomposition of molten salt, the temperature distribution in the electrical resistance heater is investigated in the present study. For this purpose, a RH has been modeled and CFD simulations have been performed. The simulation results show that the hottest regions occur on the electric rod surface behind the last baffle. A technical optimization was performed by adjusting three parameters: Shell-baffle clearance, electric rod-baffle clearance and number of baffles. After the technical optimization was carried out, the temperature difference between the maximum temperature and the average outlet temperature of the salt is within the acceptable limits, thus critical salt decomposition has been avoided. Additionally, the CFD simulations results were analyzed and compared with results obtained with a one-dimensional model in Modelica.},
  language  = {en}
}
@inproceedings{CaminosSchmitzAttietal.2022,
  author    = {Caminos, Ricardo Alexander Chico and Schmitz, Pascal and Atti, Vikrama and Mahdi, Zahra and Teixeira Boura, Cristiano Jos{\´e} and Sattler, Johannes Christoph and Herrmann, Ulf and Hilger, Patrick and Dieckmann, Simon},
  title     = {Development of a micro heliostat and optical qualification assessment with a 3D laser scanning method},
  series = {SOLARPACES 2020},
  booktitle = {SOLARPACES 2020},
  number    = {2445 / 1},
  publisher = {AIP conference proceedings / American Institute of Physics},
  address   = {Melville, NY},
  isbn      = {978-0-7354-4195-8},
  issn      = {1551-7616 (online)},
  doi       = {10.1063/5.0086262},
  pages     = {8 Seiten},
  year      = {2022},
  abstract  = {The Solar-Institut J{\"u}lich (SIJ) and the companies Hilger GmbH and Heliokon GmbH from Germany have developed a small-scale cost-effective heliostat, called "micro heliostat". Micro heliostats can be deployed in small-scale concentrated solar power (CSP) plants to concentrate the sun's radiation for electricity generation, space or domestic water heating or industrial process heat. In contrast to conventional heliostats, the special feature of a micro heliostat is that it consists of dozens of parallel-moving, interconnected, rotatable mirror facets. The mirror facets array is fixed inside a box-shaped module and is protected from weathering and wind forces by a transparent glass cover. The choice of the building materials for the box, tracking mechanism and mirrors is largely dependent on the selected production process and the intended application of the micro heliostat. Special attention was paid to the material of the tracking mechanism as this has a direct influence on the accuracy of the micro heliostat. The choice of materials for the mirror support structure and the tracking mechanism is made in favor of plastic molded parts. A qualification assessment method has been developed by the SIJ in which a 3D laser scanner is used in combination with a coordinate measuring machine (CMM). For the validation of this assessment method, a single mirror facet was scanned and the slope deviation was computed.},
  language  = {en}
}
@inproceedings{NiederwestbergSchneiderTeixeiraBouraetal.2022,
  author    = {Niederwestberg, Stefan and Schneider, Falko and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Introduction to a direct irradiated transparent tube particle receiver},
  series = {SOLARPACES 2020},
  booktitle = {SOLARPACES 2020},
  number    = {2445 / 1},
  publisher = {AIP conference proceedings / American Institute of Physics},
  address   = {Melville, NY},
  isbn      = {978-0-7354-4195-8},
  issn      = {1551-7616 (online)},
  doi       = {10.1063/5.0086735},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {New materials often lead to innovations and advantages in technical applications. This also applies to the particle receiver proposed in this work that deploys high-temperature and scratch resistant transparent ceramics. With this receiver design, particles are heated through direct-contact concentrated solar irradiance while flowing downwards through tubular transparent ceramics from top to bottom. In this paper, the developed particle receiver as well as advantages and disadvantages are described. Investigations on the particle heat-up characteristics from solar irradiance were carried out with DEM simulations which indicate that particle temperatures can reach up to 1200 K. Additionally, a simulation model was set up for investigating the dynamic behavior. A test receiver at laboratory scale has been designed and is currently being built. In upcoming tests, the receiver test rig will be used to validate the simulation results. The design and the measurement equipment is described in this work.},
  language  = {en}
}