@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}
}
@incollection{HoffschmidtAlexopoulosRauetal.2022,
  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, B. and Chico Caminos, R.A. and Rend{\´o}n, C. and Hilger, P.},
  title     = {Concentrating solar power},
  series = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications},
  booktitle = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-0-12-819734-9},
  pages     = {670 -- 724},
  year      = {2022},
  abstract  = {The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems. The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours. Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage. Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described. Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail. The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world.},
  language  = {en}
}
@incollection{HoffschmidtAlexopoulosRauetal.2021,
  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, B. and Caminos, R.A. Chico and Rend{\´o}n, C. and Hilger, P.},
  title     = {Concentrating Solar Power},
  series = {Earth systems and environmental sciences},
  booktitle = {Earth systems and environmental sciences},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-0-12-409548-9},
  doi       = {10.1016/B978-0-12-819727-1.00089-3},
  year      = {2021},
  abstract  = {The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems. The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours. Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage. Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described. Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail. The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world.},
  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}
}
@incollection{HoffschmidtAlexopoulosGoettscheetal.2022,
  author    = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and G{\"o}ttsche, Joachim and Sauerborn, Markus and Kaufhold, O.},
  title     = {High Concentration Solar Collectors},
  series = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications},
  booktitle = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-0-12-819734-9},
  doi       = {10.1016/B978-0-12-819727-1.00058-3},
  pages     = {198 -- 245},
  year      = {2022},
  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 article, different criteria for the choice of technology are analyzed in detail.},
  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{GoettscheHoffschmidtAlexopoulosetal.2008,
  author    = {G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Alexopoulos, Spiros and Funke, J. and Schwarzb{\"o}zl, P.},
  title     = {First Simulation Results for the Hybridization of Small Solar Power Tower Plants},
  series = {EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings, 2008-10-07 - 2008-10-10, Lissabon (Portugal). Vol. 1},
  journal   = {EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings, 2008-10-07 - 2008-10-10, Lissabon (Portugal). Vol. 1},
  publisher = {Sociedade Portuguesa De Energia Solar (SPES)},
  address   = {Lisbon},
  isbn      = {978-1-61782-228-5},
  pages     = {1299 -- 1306},
  year      = {2008},
  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{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{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{ElMoussaouiKassmiAlexopoulosetal.2021,
  author    = {El Moussaoui, Noureddine and Kassmi, Khalil and Alexopoulos, Spiros and Schwarzer, Klemens and Chayeb, Hamid and Bachiri, Najib},
  title     = {Simulation studies on a new innovative design of a hybrid solar distiller MSDH alimented with a thermal and photovoltaic energy},
  series = {Materialstoday: Proceedings},
  booktitle = {Materialstoday: Proceedings},
  issn      = {2214-7853},
  doi       = {10.1016/j.matpr.2021.03.115},
  year      = {2021},
  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{BreitbachAlexopoulosHoffschmidt2007,
  author    = {Breitbach, Gerd and Alexopoulos, Spiros and Hoffschmidt, Bernhard},
  title     = {Fluid flow in porous ceramic multichannel crossflower filter modules},
  publisher = {COMSOL Inc.},
  address   = {Burlington, Mass.},
  pages     = {5 S.},
  year      = {2007},
  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}
}
@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{AlexopoulosHoffschmidtRauetal.2009,
  author    = {Alexopoulos, Spiros and Hoffschmidt, Bernhard and Rau, Christoph and Schwarzb{\"o}zl, Peter},
  title     = {Simulation results for a hybridization concept of a small solar tower power plant},
  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. Luft- u. Raumfahrt},
  address   = {Stuttgart},
  isbn      = {9783000287558},
  pages     = {1 CD-ROM},
  year      = {2009},
  language  = {en}
}
@inproceedings{AlexopoulosHoffschmidtRauetal.2010,
  author    = {Alexopoulos, Spiros and Hoffschmidt, Bernhard and Rau, Christoph and Schmitz, M. and Schwarzb{\"o}zl, P. and Pomp, Stefan},
  title     = {Simulation results for a hybridized operation of a gas turbine or a burner for a small solar tower power plant},
  series = {SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France},
  booktitle = {SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France},
  publisher = {Soc. OSC},
  address   = {Saint Maur},
  pages     = {82 -- 83},
  year      = {2010},
  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}
}
@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{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}
}
@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}
}
@inproceedings{AlexopoulosBreitbachHoffschmidt2009,
  author    = {Alexopoulos, Spiros and Breitbach, Gerd and Hoffschmidt, Bernhard},
  title     = {Optimization of the channel form geometry of porous ReSiC ceramic membrane modules},
  series = {Proceedings / International Conference \& Exhibition for Filtration and Separation Technology, FILTECH 2009 : October 13 - 15, 2009, Wiesbaden, Germany. Vol. 2},
  booktitle = {Proceedings / International Conference \& Exhibition for Filtration and Separation Technology, FILTECH 2009 : October 13 - 15, 2009, Wiesbaden, Germany. Vol. 2},
  publisher = {Filtech Exhibitions Germany},
  address   = {Meerbusch},
  isbn      = {978-3-941655-36-2},
  pages     = {686 -- 693},
  year      = {2009},
  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}
}
@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}
}
@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{AhlbrinkAlexopoulosAnderssonetal.2009,
  author    = {Ahlbrink, N. and Alexopoulos, Spiros and Andersson, J. and Belhomme, B. and Teixeira Boura, Cristiano Jos{\´e} and Gall, J. and Hirsch, T.},
  title     = {viCERP - the Virtual Institute of Central Receiver Power Plant},
  series = {MATHMOD 2009 - 6th Vienna International Conference on Mathematical Modelling : February 11 - 13, 2009, Vienna, Austria. ARGESIM Report. No. 35},
  booktitle = {MATHMOD 2009 - 6th Vienna International Conference on Mathematical Modelling : February 11 - 13, 2009, Vienna, Austria. ARGESIM Report. No. 35},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-3-901608-35-3},
  year      = {2009},
  language  = {en}
}