@inproceedings{HoffschmidtTelleSauerbornetal.2011,
  author    = {Hoffschmidt, Bernhard and Telle, R. and Sauerborn, Markus and Wagner, M.},
  title     = {Optical measurement system for high temperature absorbers},
  series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  address   = {Granada},
  pages     = {1 CD-ROM},
  year      = {2011},
  language  = {en}
}
@inproceedings{HirschAhlbrinkPitzPaaletal.2011,
  author    = {Hirsch, Tobias and Ahlbrink, Nils and Pitz-Paal, Robert and Teixeira Boura, Cristiano Jos{\´e} and Hoffschmidt, Bernhard and Gall, Jan and Abel, Dirk and Nolte, Vera and Wirsum, Manfred and Andersson, Joel and Diehl, Moritz},
  title     = {Dynamic simulation of a solar tower system with open volumetric receiver - a review on the ViCERP project},
  series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  address   = {Granada},
  pages     = {1 CD-ROM},
  year      = {2011},
  language  = {en}
}
@inproceedings{BaumannTeixeiraBouraGoettscheetal.2011,
  author    = {Baumann, Torsten and Teixeira Boura, Cristiano Jos{\´e} and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Zunft, Stefan},
  title     = {Air-sand heat exchanger: materials and flow properties},
  series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  address   = {Granada},
  pages     = {1 CD-ROM},
  year      = {2011},
  language  = {en}
}
@inproceedings{FrickeZiolkoAnthrakidisetal.2011,
  author    = {Fricke, Barbara and Ziolko, C. and Anthrakidis, Anette and Alexopoulos, Spiros and Hoffschmidt, Bernhard and Dillig, M. and Giese, F.},
  title     = {InnoSol - life cycle analysis of solar power tower plants},
  series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  address   = {Granada},
  pages     = {1 CD-ROM},
  year      = {2011},
  language  = {en}
}
@inproceedings{AlexopoulosHoffschmidtRauetal.2011,
  author    = {Alexopoulos, Spiros and Hoffschmidt, Bernhard and Rau, Christoph and Sattler, Johannes Christoph},
  title     = {Choice of solar share of a hybrid power plant of a central receiver system and a biogas plant in dependency of the geographical latitude},
  series = {World Renewable Energy Congress-Sweden : 8 -13 May, 2011, Link{\"o}ping, Sweden / ed.: Bahram Moshfegh},
  booktitle = {World Renewable Energy Congress-Sweden : 8 -13 May, 2011, Link{\"o}ping, Sweden / ed.: Bahram Moshfegh},
  publisher = {Univ. Electronic Pr.},
  address   = {Link{\"o}ping},
  isbn      = {9789173930703},
  pages     = {3710 -- 3717},
  year      = {2011},
  language  = {en}
}
@inproceedings{AchenbachGeimerGoettscheetal.2011,
  author    = {Achenbach, Timm and Geimer, K. and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Lynen, A. and Bauer, J.},
  title     = {Simulation and flow measurements of volumetric high temperature absorbers for solar tower power plants},
  series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  address   = {Granada},
  pages     = {1 CD-ROM},
  year      = {2011},
  language  = {en}
}
@inproceedings{TeixeiraBouraEcksteinFelinksetal.2011,
  author    = {Teixeira Boura, Cristiano Jos{\´e} and Eckstein, J. and Felinks, J. and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, S.},
  title     = {3-D CFD simulation of an air-sand heat exchanger},
  series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  address   = {Granada},
  pages     = {1 CD-ROM},
  year      = {2011},
  language  = {en}
}
@inproceedings{AchenbachGoettscheKaufholdetal.2011,
  author    = {Achenbach, Timm and G{\"o}ttsche, Joachim and Kaufhold, O. and Hoffschmidt, Bernhard},
  title     = {Development of an edge module for open volumetric receiver for the use of the radiation at the receiver boundary region},
  series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  address   = {Granada},
  pages     = {1 CD-ROM},
  year      = {2011},
  language  = {en}
}
@inproceedings{AlexopoulosHoffschmidtRau2011,
  author    = {Alexopoulos, Spiros and Hoffschmidt, Bernhard and Rau, Christoph},
  title     = {Comparison of steady-state and transient simulations for solar tower power plants with open-volumetric receiver},
  series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain},
  address   = {Granada},
  pages     = {1 CD-ROM},
  year      = {2011},
  language  = {en}
}
@inproceedings{SauerbornHoffschmidtTelleetal.2012,
  author    = {Sauerborn, Markus and Hoffschmidt, Bernhard and Telle, R. and Wagner, M.},
  title     = {Heatable optical analyse system for high temperature absorbers},
  series = {30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5},
  booktitle = {30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5},
  publisher = {Curran},
  address   = {Red Hook, NY},
  organization    = {International Solar Energy Society},
  isbn      = {978-1-61839-364-7},
  pages     = {3852 -- 3860},
  year      = {2012},
  language  = {en}
}
@inproceedings{SauerbornArshadiRohrmoser2012,
  author    = {Sauerborn, Markus and Arshadi, S. and Rohrmoser, R.},
  title     = {Influence of clouds and aerosols to the haze of the sunshape},
  series = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 5},
  booktitle = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 5},
  publisher = {Curran},
  address   = {Red Hook, NY},
  organization    = {International Solar Energy Society},
  pages     = {3887 -- 3894},
  year      = {2012},
  language  = {en}
}
@article{ReisgenSchleserAbdurakhmanovetal.2012,
  author    = {Reisgen, Uwe and Schleser, Markus and Abdurakhmanov, Aydemir and Turichin, Gleb and Valdaitseva, Elena and Bach, Friedrich-Wilhelm and Hassel, Thomas and Beniyashi, Alexander},
  title     = {Investigation of factors influencing the formation of weld defects in non-vacuum electron beam welding},
  series = {The Paton welding journal},
  volume    = {2012},
  journal   = {The Paton welding journal},
  number    = {2},
  publisher = {Paton Publishing House},
  address   = {Kiev},
  issn      = {0957-798X},
  pages     = {11 -- 18},
  year      = {2012},
  abstract  = {The influence of welding condition parameters and properties of material on formation of defects, such as humping and undercuts, in non-vacuum electron beam welding was investigated. The influence of separate welding parameters on the quality of welds was determined.},
  language  = {en}
}
@inproceedings{FrickeZiolkoAnthrakidisetal.2012,
  author    = {Fricke, Barbara and Ziolko, C. and Anthrakidis, Anette and Alexopoulos, Spiros and Hoffschmidt, Bernhard and Giese, F. and Dillig, M.},
  title     = {InnoSol - environmental aspects of the open volumetric receiver technology},
  series = {30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5},
  booktitle = {30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5},
  publisher = {Curran},
  address   = {Red Hook, NY},
  organization    = {International Solar Energy Society},
  pages     = {3895 -- 3900},
  year      = {2012},
  language  = {en}
}
@inproceedings{SauerbornKlimekHoffschmidtetal.2012,
  author    = {Sauerborn, Markus and Klimek, J. and Hoffschmidt, Bernhard and Essen, H. and Sieger, S. and Biegel, G. and G{\"o}ttsche, Joachim and Hilger, Patrick},
  title     = {Eurosun 2012 : radar technology for heliostat posititon control},
  series = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012},
  booktitle = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012},
  address   = {Rijeka},
  pages     = {ID 80},
  year      = {2012},
  language  = {en}
}
@inproceedings{AchenbachGeimerLynenetal.2012,
  author    = {Achenbach, Timm and Geimer, Konstantin and Lynen, Arthur and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard},
  title     = {Simulation of thermo-mechanical processes in open volumetric absorber modules},
  series = {SolarPaces 2012 : concentrating solar power and chemical energy systems : Sept. 11 - 14 2012, Marrakech, Marokko},
  booktitle = {SolarPaces 2012 : concentrating solar power and chemical energy systems : Sept. 11 - 14 2012, Marrakech, Marokko},
  pages     = {1 -- 8},
  year      = {2012},
  language  = {en}
}
@incollection{HoffschmidtAlexopoulosGoettscheetal.2012,
  author    = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and G{\"o}ttsche, Joachim and Sauerborn, Markus},
  title     = {High concentration solar collectors},
  series = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications},
  volume    = {3},
  booktitle = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-0-08-087873-7},
  doi       = {10.1016/B978-0-08-087872-0.00306-1},
  pages     = {165 -- 209},
  year      = {2012},
  abstract  = {Solar thermal concentrated power is an emerging technology that provides clean electricity for the growing energy market. To the solar thermal concentrated power plant systems belong the parabolic trough, the Fresnel collector, the solar dish, and the central receiver system. For high-concentration solar collector systems, optical and thermal analysis is essential. There exist a number of measurement techniques and systems for the optical and thermal characterization of the efficiency of solar thermal concentrated systems. For each system, structure, components, and specific characteristics types are described. The chapter presents additionally an outline for the calculation of system performance and operation and maintenance topics. One main focus is set to the models of components and their construction details as well as different types on the market. In the later part of this chapter, different criteria for the choice of technology are analyzed in detail.},
  language  = {en}
}
@article{Alexopoulos2012,
  author    = {Alexopoulos, Spiros},
  title     = {Biogas systems: basics, biogas multifunction, principle of fermentation and hybrid application with a solar tower for the treatment of waste animal manure},
  series = {Journal of Engineering Science and Technology Review},
  volume    = {5},
  journal   = {Journal of Engineering Science and Technology Review},
  number    = {4},
  issn      = {1791-2377},
  pages     = {48 -- 55},
  year      = {2012},
  abstract  = {Two of the main environmental problems of today's society are the continuously increasing production of organic wastes as well as the increase of carbon dioxide in the atmosphere and the related green house effect. A way to solve these problems is the production of biogas. Biogas is a combustible gas consisting of methane, carbon dioxide and small amounts of other gases and trace elements. Production of biogas through anaerobic digestion of animal manure and slurries as well as of a wide range of digestible organic wastes and agricultural residues, converts these substrates into electricity and heat and offers a natural fertiliser for agriculture. The microbiological process of decomposition of organic matter, in the absence of oxygen takes place in reactors, called digesters. Biogas can be used as a fuel in a gas turbine or burner and can be used in a hybrid solar tower system offering a solution for waste treatment of agricultural and animal residues. A solar tower system consists of a heliostat field, which concentrates direct solar irradiation on an open volumetric central receiver. The receiver heats up ambient air to temperatures of around 700°C. The hot air's heat energy is transferred to a steam Rankine cycle in a heat recovery steam generator (HRSG). The steam drives a steam turbine, which in turn drives a generator for producing electricity. In order to increase the operational hours of a solar tower power plant, a heat storage system and/ or hybridization may be considered. The advantage of solar-fossil hybrid power plants, compared to solar-only systems, lies in low additional investment costs due to an adaptable solar share and reduced technical and economical risks. On sunny days the hybrid system operates in a solar-only mode with the central receiver and on cloudy days and at night with the gas turbine only. As an alternative to methane gas, environmentally neutral biogas can be used for operating the gas turbine. Hence, the hybrid system is operated to 100\% from renewable energy sources},
  language  = {en}
}
@inproceedings{AlexopoulosKluczkaVaessenetal.2012,
  author    = {Alexopoulos, Spiros and Kluczka, Sven and Vaeßen, Christiane and Roeb, M. and Neises, M.},
  title     = {Scenario development for efficient methanol production using CO2 and solar energy},
  series = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012},
  booktitle = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012},
  address   = {Rijeka},
  pages     = {ID 99},
  year      = {2012},
  language  = {en}
}
@inproceedings{BaumannTeixeiraBouraEcksteinetal.2012,
  author    = {Baumann, Torsten and Teixeira Boura, Cristiano Jos{\´e} and Eckstein, Julian and Dabrowski, Jan and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Zunft, Stefan},
  title     = {Properties of bulk materials for high-temperature air-sand heat exchangers},
  series = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 2},
  booktitle = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 2},
  publisher = {Curran},
  address   = {Red Hook, NY},
  organization    = {International Solar Energy Society},
  isbn      = {978-1-61839-364-7},
  pages     = {1270 -- 1278},
  year      = {2012},
  language  = {en}
}
@inproceedings{AlexopoulosRauHoffschmidtetal.2012,
  author    = {Alexopoulos, Spiros and Rau, Christoph and Hoffschmidt, Bernhard and Breitbach, Gerd and Latzke, Markus},
  title     = {Modelling and validation of a transient heat recovery steam generator of the solar tower power plant Juelich},
  series = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012},
  booktitle = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012},
  address   = {Rijeka},
  pages     = {ID 97},
  year      = {2012},
  language  = {en}
}
@incollection{HoffschmidtAlexopoulosRauetal.2012,
  author    = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and Rau, Christoph and Sattler, Johannes Christoph and Anthrakidis, Anette and Teixeira Boura, Cristiano Jos{\´e} and O'Connor, P. and Hilger, Patrick},
  title     = {Concentrating solar power},
  series = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications},
  volume    = {3},
  booktitle = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-0-08-087872-0},
  doi       = {10.1016/B978-0-08-087872-0.00319-X},
  pages     = {595 -- 636},
  year      = {2012},
  language  = {en}
}
@inproceedings{AlexopoulosHoffschmidtRauetal.2012,
  author    = {Alexopoulos, Spiros and Hoffschmidt, Bernhard and Rau, Christoph and Sattler, Johannes Christoph},
  title     = {Simulation of hybrid solar tower power plants},
  series = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 5},
  booktitle = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 5},
  publisher = {Curran},
  address   = {Red Hook, NY},
  organization    = {International Solar Energy Society},
  pages     = {4044 -- 4050},
  year      = {2012},
  language  = {en}
}
@article{VieiradaSilvaSchwarzerHoffschmidtetal.2013,
  author    = {Vieira da Silva, Maria Eugenia and Schwarzer, Klemens and Hoffschmidt, Bernhard and Pinheiro Rodrigues, Frederico and Schwarzer, Tarik and Costa Rocha, Paulo Alexandre},
  title     = {Mass transfer correlation for evaporation-condensation thermal process in the range of 70 °C-95 °C},
  series = {Renewable energy},
  volume    = {Vol. 53},
  journal   = {Renewable energy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1879-0682 (E-Journal); 0960-1481 (Print)},
  pages     = {174 -- 179},
  year      = {2013},
  language  = {en}
}
@incollection{Alexopoulos2013,
  author    = {Alexopoulos, Spiros},
  title     = {Biomass technology and bio-fuels: Heating/cooling and power},
  series = {Renewable energy systems : theory, innovations, and intelligent applications / eds.: Socrates Kaplanis and Eleni Kaplani},
  booktitle = {Renewable energy systems : theory, innovations, and intelligent applications / eds.: Socrates Kaplanis and Eleni Kaplani},
  publisher = {Nova Science Publ.},
  address   = {Hauppauge, NY},
  isbn      = {9781624177415},
  pages     = {501 -- 523},
  year      = {2013},
  language  = {en}
}
@inproceedings{AchenbachBoschBreitbachetal.2013,
  author    = {Achenbach, Timm and Bosch, Timo and Breitbach, Gerd and G{\"o}ttsche, Joachim and Sauerborn, Markus},
  title     = {Theoretical and experimental investigations regarding open volumetric receivers of CRS},
  series = {Energy procedia : proceedings of the SolarPACES 2013 International Conference},
  volume    = {Vol. 49},
  booktitle = {Energy procedia : proceedings of the SolarPACES 2013 International Conference},
  issn      = {1876-6102},
  pages     = {1259 -- 1268},
  year      = {2013},
  language  = {en}
}
@article{KronhardtAlexopoulosReisseletal.2014,
  author    = {Kronhardt, Valentina and Alexopoulos, Spiros and Reißel, Martin and Sattler, Johannes Christoph and Hoffschmidt, Bernhard and H{\"a}nel, Matthias and Doerbeck, Till},
  title     = {High-temperature thermal storage system for solar tower power plants with open-volumetric air receiver simulation and energy balancing of a discretized model},
  series = {Energy procedia},
  volume    = {49},
  journal   = {Energy procedia},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1876-6102 (E-Journal) ; 1876-6102 (Print)},
  doi       = {10.1016/j.egypro.2014.03.094},
  pages     = {870 -- 877},
  year      = {2014},
  abstract  = {This paper describes the modeling of a high-temperature storage system for an existing solar tower power plant with open volumetric receiver technology, which uses air as heat transfer medium (HTF). The storage system model has been developed in the simulation environment Matlab/Simulink®. The storage type under investigation is a packed bed thermal energy storage system which has the characteristics of a regenerator. Thermal energy can be stored and discharged as required via the HTF air. The air mass flow distribution is controlled by valves, and the mass flow by two blowers. The thermal storage operation strategy has a direct and significant impact on the energetic and economic efficiency of the solar tower power plants.},
  language  = {en}
}
@article{KluczkaEcksteinAlexopoulosetal.2014,
  author    = {Kluczka, Sven and Eckstein, Julian and Alexopoulos, Spiros and Vaeßen, Christiane and Roeb, Martin},
  title     = {Process simulation for solar steam and dry reforming},
  series = {Energy procedia : Proceedings of the SolarPACES 2013 International Conference},
  volume    = {49},
  journal   = {Energy procedia : Proceedings of the SolarPACES 2013 International Conference},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1876-6102 (E-Journal)},
  doi       = {10.1016/j.egypro.2014.03.092},
  pages     = {850 -- 859},
  year      = {2014},
  abstract  = {In co-operation with the German Aerospace Center, the Solar-Institut J{\"u}lich has been analyzing the different technologies that are available for methanol production from CO2 using solar energy. The aim of the project is to extract CO2 from industrial exhaust gases or directly from the atmosphere to recycle it by use of solar energy. Part of the study was the modeling and simulating of a methane reformer for the production of synthesis gas, which can be operated by solar or hybrid heat sources. The reformer has been simplified in such a way that the model is accurate and enables fast calculations. The developed pseudo-homogeneous one- dimensional model can be regarded as a kind of counter-current heat exchanger and is able to incorporate a steam reforming reaction as well as a dry reforming reaction.},
  language  = {en}
}
@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}
}
@article{RauAlexopoulosBreitbachetal.2014,
  author    = {Rau, Christoph and Alexopoulos, Spiros and Breitbach, Gerd and Hoffschmidt, Bernhard and Latzke, Markus and Sattler, Johannes Christoph},
  title     = {Transient simulation of a solar-hybrid tower power plant with open volumetric receiver at the location Barstow},
  series = {Energy procedia : proceedings of the SolarPACES 2013 International Conference},
  volume    = {49},
  journal   = {Energy procedia : proceedings of the SolarPACES 2013 International Conference},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1876-6102},
  doi       = {10.1016/j.egypro.2014.03.157},
  pages     = {1481 -- 1490},
  year      = {2014},
  abstract  = {In this work the transient simulations of four hybrid solar tower power plant concepts with open-volumetric receiver technology for a location in Barstow-Daggett, USA, are presented. The open-volumetric receiver uses ambient air as heat transfer fluid and the hybridization is realized with a gas turbine. The Rankine cycle is heated by solar-heated air and/or by the gas turbine's flue gases. The plant can be operated in solar-only, hybrid parallel or combined cycle-only mode as well as in any intermediate load levels where the solar portion can vary between 0 to 100\%. The simulated plant is based on the configuration of a solar-hybrid power tower project, which is in planning for a site in Northern Algeria. The meteorological data for Barstow-Daggett was taken from the software meteonorm. The solar power tower simulation tool has been developed in the simulation environment MATLAB/Simulink and is validated.},
  language  = {en}
}
@inproceedings{LatzkeAlexopoulosKronhardtetal.2015,
  author    = {Latzke, Markus and Alexopoulos, Spiros and Kronhardt, Valentina and Rend{\´o}n, Carlos and Sattler, Johannes Christoph},
  title     = {Comparison of Potential Sites in China for Erecting a Hybrid Solar Tower Power Plant with Air Receiver},
  series = {Energy Procedia},
  booktitle = {Energy Procedia},
  issn      = {1876-6102},
  doi       = {10.1016/j.egypro.2015.03.142},
  pages     = {1327 -- 1334},
  year      = {2015},
  language  = {en}
}
@article{Alexopoulos2015,
  author    = {Alexopoulos, Spiros},
  title     = {Simulation model for the transient process behaviour of solar aluminium recycling in a rotary kiln},
  series = {Applied Thermal Engineering},
  volume    = {78},
  journal   = {Applied Thermal Engineering},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1359-4311},
  doi       = {10.1016/j.applthermaleng.2015.01.007},
  pages     = {387 -- 396},
  year      = {2015},
  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{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}
}
@article{WoliszSchuetzBlankeetal.2017,
  author    = {Wolisz, Henryk and Sch{\"u}tz, Thomas and Blanke, Tobias and Hagenkamp, Markus and Kohrn, Markus and Wesseling, Mark and M{\"u}ller, Dirk},
  title     = {Cost optimal sizing of smart buildings' energy system components considering changing end-consumer electricity markets},
  series = {Energy},
  volume    = {137},
  journal   = {Energy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.energy.2017.06.025},
  pages     = {715 -- 728},
  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}
}
@article{AlexopoulosHoffschmidt2017,
  author    = {Alexopoulos, Spiros and Hoffschmidt, Bernhard},
  title     = {Advances in solar tower technology},
  series = {Wiley interdisciplinary reviews : Energy and Environment : WIREs},
  volume    = {6},
  journal   = {Wiley interdisciplinary reviews : Energy and Environment : WIREs},
  number    = {1},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {2041-840X},
  doi       = {10.1002/wene.217},
  pages     = {1 -- 19},
  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}
}
@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{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}
}
@article{PuppeGiulianoFrantzetal.2018,
  author    = {Puppe, Michael and Giuliano, Stefano and Frantz, Cathy and Uhlig, Ralf and Schumacher, Ralph and Ibraheem, Wagdi and Schmalz, Stefan and Waldmann, Barbara and Guder, Christoph and Peter, Dennis and Schwager, Christian and Teixeira Boura, Cristiano Jos{\´e} and Alexopoulos, Spiros and Spiegel, Michael and Wortmann, J{\"u}rgen and Hinrichs, Matthias and Engelhard, Manfred and Aust, Michael},
  title     = {Techno-economic optimization of molten salt solar tower plants},
  series = {AIP Conference Proceedings art.no. 040033},
  volume    = {2033},
  journal   = {AIP Conference Proceedings art.no. 040033},
  number    = {Issue 1},
  publisher = {AIP Publishing},
  address   = {Melville, NY},
  doi       = {10.1063/1.5067069},
  year      = {2018},
  abstract  = {In this paper the results of a techno-economic analysis of improved and optimized molten salt solar tower plants (MSSTP plants) are presented. The potential improvements that were analyzed include different receiver designs, different designs of the HTF-system and plant control, increased molten salt temperatures (up to 640°C) and multi-tower systems. Detailed technological and economic models of the solar field, solar receiver and high temperature fluid system (HTF-system) were developed and used to find potential improvements compared to a reference plant based on Solar Two technology and up-to-date cost estimations. The annual yield model calculates the annual outputs and the LCOE of all variants. An improved external tubular receiver and improved HTF-system achieves a significant decrease of LCOE compared to the reference. This is caused by lower receiver cost as well as improvements of the HTF-system and plant operation strategy, significantly reducing the plant own consumption. A novel star receiver shows potential for further cost decrease. The cavity receiver concepts result in higher LCOE due to their high investment cost, despite achieving higher efficiencies. Increased molten salt temperatures seem possible with an adapted, closed loop HTF-system and achieve comparable results to the original improved system (with 565°C) under the given boundary conditions. In this analysis all multi tower systems show lower economic viability compared to single tower systems, caused by high additional cost for piping connections and higher cost of the receivers. REFERENCES},
  language  = {en}
}
@inproceedings{BlankeDringVonteinetal.2018,
  author    = {Blanke, Tobias and Dring, Bernd and Vontein, Marius and Kuhnhenne, Markus},
  title     = {Climate Change Mitigation Potentials of Vertical Building Integrated Photovoltaic},
  series = {8th International Workshop on Integration of Solar Power into Power Systems : 16-17 October 2018, Stockholm, Sweden},
  booktitle = {8th International Workshop on Integration of Solar Power into Power Systems : 16-17 October 2018, Stockholm, Sweden},
  pages     = {1 -- 7},
  year      = {2018},
  language  = {en}
}
@inproceedings{GorzalkaDahlkeGoettscheetal.2018,
  author    = {Gorzalka, Philip and Dahlke, Dennis and G{\"o}ttsche, Joachim and Israel, Martin and Patel, Dhruvkumar and Prahl, Christoph and Schmiedt, Jacob Estevam and Frommholz, Dirk and Hoffschmidt, Bernhard and Linkiewicz, Magdalena},
  title     = {Building Tomograph-From Remote Sensing Data of Existing Buildings to Building Energy Simulation Input},
  series = {EBC, Annex 71, Fifth expert meeting, October 17-19, 2018, Innsbruck, Austria},
  booktitle = {EBC, Annex 71, Fifth expert meeting, October 17-19, 2018, Innsbruck, Austria},
  pages     = {17 Seiten},
  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}
}
@article{GoettscheAlexopoulosDuemmleretal.2019,
  author    = {G{\"o}ttsche, Joachim and Alexopoulos, Spiros and D{\"u}mmler, Andreas and Maddineni, S. K.},
  title     = {Multi-Mirror Array Calculations With Optical Error},
  pages     = {1 -- 6},
  year      = {2019},
  abstract  = {The optical performance of a 2-axis solar concentrator was simulated with the COMSOL Multiphysics® software. The concentrator consists of a mirror array, which was created using the application builder. The mirror facets are preconfigured to form a focal point. During tracking all mirrors are moved simultaneously in a coupled mode by 2 motors in two axes, in order to keep the system in focus with the moving sun. Optical errors on each reflecting surface were implemented in combination with the solar angular cone of ± 4.65 mrad. As a result, the intercept factor of solar radiation that is available to the receiver was calculated as a function of the transversal and longitudinal angles of incidence. In addition, the intensity distribution on the receiver plane was calculated as a function of the incidence angles.},
  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{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{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}
}
@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{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{RendonSchwagerGhiasietal.2020,
  author    = {Rendon, Carlos and Schwager, Christian and Ghiasi, Mona and Schmitz, Pascal and Bohang, Fakhri and Chico Caminos, Ricardo Alexander 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},
  abstract  = {A 16.77 kW thermal power bayonet-tube reactor for the mixed reforming of methane using solar energy has been designed and modeled. A test bench for the experimental tests has been installed at the Synlight facility in Juelich, Germany and has just been commissioned. This paper presents the solar-heated reactor design for a combined steam and dry reforming as well as a scaled-up process simulation of a solar reforming plant for methanol production. Solar power towers are capable of providing large amounts of heat to drive high-endothermic reactions, and their integration with thermochemical processes shows a promising future. In the designed bayonet-tube reactor, the conventional burner arrangement for the combustion of natural gas has been substituted by a continuous 930 °C hot air stream, provided by means of a solar heated air receiver, a ceramic thermal storage and an auxiliary firing system. Inside the solar-heated reactor, the heat is transferred by means of convective mechanism mainly; instead of radiation mechanism as typically prevailing in fossil-based industrial reforming processes. A scaled-up solar reforming plant of 50.5 MWth was designed and simulated in Dymola® and AspenPlus®. In comparison to a fossil-based industrial reforming process of the same thermal capacity, a solar reforming plant with thermal storage promises a reduction up to 57 \% of annual natural gas consumption in regions with annual DNI-value of 2349 kWh/m2. The benchmark solar reforming plant contributes to a CO2 avoidance of approx. 79 kilotons per year. This facility can produce a nominal output of 734.4 t of synthesis gas and out of this 530 t of methanol a day.},
  language  = {en}
}