@inproceedings{SchwagerAngeleNourietal.2022,
  author    = {Schwager, Christian and Angele, Florian and Nouri, Bijan and Schwarzb{\"o}zl, Peter and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Impact of DNI forecast quality on performance prediction for a commercial scale solar tower: Application of nowcasting DNI maps to dynamic solar tower simulation},
  series = {SolarPACES 2022 conference proceedings},
  booktitle = {SolarPACES 2022 conference proceedings},
  number    = {1},
  publisher = {TIB Open Publishing},
  address   = {Hannover},
  issn      = {2751-9899 (online)},
  doi       = {10.52825/solarpaces.v1i.675},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {Concerning current efforts to improve operational efficiency and to lower overall costs of concentrating solar power (CSP) plants with prediction-based algorithms, this study investigates the quality and uncertainty of nowcasting data regarding the implications for process predictions. DNI (direct normal irradiation) maps from an all-sky imager-based nowcasting system are applied to a dynamic prediction model coupled with ray tracing. The results underline the need for high-resolution DNI maps in order to predict net yield and receiver outlet temperature realistically. Furthermore, based on a statistical uncertainty analysis, a correlation is developed, which allows for predicting the uncertainty of the net power prediction based on the corresponding DNI forecast uncertainty. However, the study reveals significant prediction errors and the demand for further improvement in the accuracy at which local shadings are forecasted.},
  language  = {en}
}
@inproceedings{SchulteSchwagerFrantzetal.2022,
  author    = {Schulte, Jonas and Schwager, Christian and Frantz, Cathy and Schloms, Felix and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Control concept for a molten salt receiver in star design: Development, optimization and testing with cloud passage scenarios},
  series = {SolarPACES 2022 conference proceedings},
  booktitle = {SolarPACES 2022 conference proceedings},
  number    = {1},
  publisher = {TIB Open Publishing},
  address   = {Hannover},
  issn      = {2751-9899 (online)},
  doi       = {10.52825/solarpaces.v1i.693},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {A promising approach to reduce the system costs of molten salt solar receivers is to enable the irradiation of the absorber tubes on both sides. The star design is an innovative receiver design, pursuing this approach. The unconventional design leads to new challenges in controlling the system. This paper presents a control concept for a molten salt receiver system in star design. The control parameters are optimized in a defined test cycle by minimizing a cost function. The control concept is tested in realistic cloud passage scenarios based on real weather data. During these tests, the control system showed no sign of unstable behavior, but to perform sufficiently in every scenario further research and development like integrating Model Predictive Controls (MPCs) need to be done. The presented concept is a starting point to do so.},
  language  = {en}
}
@inproceedings{LahrsKrisamHerrmann2023,
  author    = {Lahrs, Lennart and Krisam, Pierre and Herrmann, Ulf},
  title     = {Envisioning a collaborative energy system planning platform for the energy transition at the district level},
  series = {ECOS 2023. The 36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems},
  booktitle = {ECOS 2023. The 36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems},
  publisher = {Procedings of ECOS 2023},
  doi       = {10.52202/069564-0284},
  pages     = {3163 -- 3170},
  year      = {2023},
  abstract  = {Residential and commercial buildings account for more than one-third of global energy-related greenhouse gas emissions. Integrated multi-energy systems at the district level are a promising way to reduce greenhouse gas emissions by exploiting economies of scale and synergies between energy sources. Planning district energy systems comes with many challenges in an ever-changing environment. Computational modelling established itself as the state-of-the-art method for district energy system planning. Unfortunately, it is still cumbersome to combine standalone models to generate insights that surpass their original purpose. Ideally, planning processes could be solved by using modular tools that easily incorporate the variety of competing and complementing computational models. Our contribution is a vision for a collaborative development and application platform for multi-energy system planning tools at the district level. We present challenges of district energy system planning identified in the literature and evaluate whether this platform can help to overcome these challenges. Further, we propose a toolkit that represents the core technical elements of the platform. Lastly, we discuss community management and its relevance for the success of projects with collaboration and knowledge sharing at their core.},
  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}
}
@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{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}
}
@incollection{HebelHerrmannRitzetal.2022,
  author    = {Hebel, Christoph and Herrmann, Ulf and Ritz, Thomas and R{\"o}th, Thilo and Anthrakidis, Anette and B{\"o}ker, J{\"o}rg and Franzke, Till and Grodzki, Thomas and Merkens, Torsten and Sch{\"o}ttler, Mirjam},
  title     = {FlexSHARE - Methodisches Framework zur innovativen Gestaltung der urbanen Mobilit{\"a}t durch Sharing- Angebote},
  series = {Transforming Mobility - What Next?},
  booktitle = {Transforming Mobility - What Next?},
  publisher = {Springer Gabler},
  address   = {Wiesbaden},
  isbn      = {978-3-658-36429-8},
  doi       = {10.1007/978-3-658-36430-4_10},
  pages     = {153 -- 169},
  year      = {2022},
  abstract  = {Das Ziel des INTERREG-Projektes „SHAREuregio" (FKZ: 34.EFRE-0300134) ist es, grenz{\"u}berschreitende Mobilit{\"a}t in der Euregio Rhein-Maas-Nord zu erm{\"o}glichen und zu f{\"o}rdern. Dazu soll ein elektromobiles Car- und Bikesharing- System entwickelt und in der Stadt M{\"o}nchengladbach, im Kreis Viersen sowie in den Gemeinden Roermond und Venlo (beide NL) zusammen mit den Partnern Wirtschaftsf{\"o}rderung M{\"o}nchengladbach, Wirtschaftsf{\"o}rderung f{\"u}r den Kreis Viersen, NEW AG, Goodmoovs (NL), Greenflux (NL) und der FH Aachen implementiert werden. Zun{\"a}chst richtet sich das Angebot, bestehend aus 40 Elektroautos und 40 Elektrofahrr{\"a}dern, an Unternehmen und wird nach einer Erprobungsphase, mit einer gr{\"o}ßeren Anzahl an Fahrzeugen, auch f{\"u}r Privatpersonen verf{\"u}gbar gemacht werden. Die Fahrzeuge stehen bei den jeweiligen Anwendungspartnern in Deutschland und den Niederlanden. Im Rahmen dieses Projektes hat die FH Aachen „FlexSHARE" entwickelt - ein methodisches Framework zur innovativen Gestaltung urbaner Sharing- Angebote. Das Framework erm{\"o}glicht es, anhand von messbaren Kenngr{\"o}ßen, bedarfsgerechte und auf die Region abgestimmte Sharing-Systeme zu entwickeln.},
  language  = {de}
}
@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}
}
@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{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{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}
}
@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{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}
}
@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{SchulteSchwagerNoureldinetal.2023,
  author    = {Schulte, Jonas and Schwager, Christian and Noureldin, Kareem and May, Martin and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Gradient controlled startup procedure of a molten-salt power-to-heat energy storage plant based on dynamic process simulation},
  series = {SolarPACES: Solar Power \& Chemical Energy Systems},
  booktitle = {SolarPACES: Solar Power \& Chemical Energy Systems},
  number    = {2815 / 1},
  publisher = {AIP conference proceedings / American Institute of Physics},
  address   = {Melville, NY},
  isbn      = {978-0-7354-4623-6},
  issn      = {1551-7616 (online)},
  doi       = {10.1063/5.0148741},
  pages     = {9 Seiten},
  year      = {2023},
  abstract  = {The integration of high temperature thermal energy storages into existing conventional power plants can help to reduce the CO2 emissions of those plants and lead to lower capital expenditures for building energy storage systems, due to the use of synergy effects [1]. One possibility to implement that, is a molten salt storage system with a powerful power-to-heat unit. This paper presents two possible control concepts for the startup of the charging system of such a facility. The procedures are implemented in a detailed dynamic process model. The performance and safety regarding the film temperatures at heat transmitting surfaces are investigated in the process simulations. To improve the accuracy in predicting the film temperatures, CFD simulations of the electrical heater are carried out and the results are merged with the dynamic model. The results show that both investigated control concepts are safe regarding the temperature limits. The gradient controlled startup performed better than the temperature-controlled startup. Nevertheless, there are several uncertainties that need to be investigated further.},
  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{SattlerAlexopoulosChicoCaminosetal.2019,
  author    = {Sattler, Johannes Christoph and Alexopoulos, Spiros and Chico Caminos, Ricardo Alexander 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}
}
@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{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}
}