@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{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{HoffschmidtAlexopoulos2012,
  author    = {Hoffschmidt, Bernhard and Alexopoulos, Spiros},
  title     = {Perspektiven f{\"u}r Solarthermische Kraftwerke im Sonneng{\"u}rtel},
  series = {Energiewende : Aspekte, Optionen, Herausforderungen : Vortr{\"a}ge auf der DPG-Fr{\"u}hjahrstagung Arbeitskreis Energie in der Deutschen Physikalischen Gesellschaft Berlin, 26. bis 28. M{\"a}rz 2012 / hrsg. von Hardo Bruhns},
  booktitle = {Energiewende : Aspekte, Optionen, Herausforderungen : Vortr{\"a}ge auf der DPG-Fr{\"u}hjahrstagung Arbeitskreis Energie in der Deutschen Physikalischen Gesellschaft Berlin, 26. bis 28. M{\"a}rz 2012 / hrsg. von Hardo Bruhns},
  publisher = {DPG},
  address   = {Baf Honnef},
  pages     = {81 -- 93},
  year      = {2012},
  language  = {de}
}
@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}
}
@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}
}
@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}
}
@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.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{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}
}
@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{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{AlexopoulosRauSattleretal.2011,
  author    = {Alexopoulos, Spiros and Rau, Christoph and Sattler, Johannes, Christoph and Kronhardt, Valentina and Hoffschmidt, Bernhard},
  title     = {Simulation von Solarturmkraftwerken mit offenem volumetrischen Receiver am Standort Italien},
  series = {Forschung und Entwicklung f{\"u}r solarthermische Kraftwerke : 14. K{\"o}lner Sonnenkolloquium Mittwoch, 13. Juli 2011, im Auditorium des Campus J{\"u}lich der FH Aachen : Kurzfassungen der Vortr{\"a}ge und Poster},
  booktitle = {Forschung und Entwicklung f{\"u}r solarthermische Kraftwerke : 14. K{\"o}lner Sonnenkolloquium Mittwoch, 13. Juli 2011, im Auditorium des Campus J{\"u}lich der FH Aachen : Kurzfassungen der Vortr{\"a}ge und Poster},
  publisher = {DLR},
  address   = {K{\"o}ln},
  pages     = {4 S.},
  year      = {2011},
  language  = {de}
}
@inproceedings{VaessenAlexopoulosKluczkaetal.2011,
  author    = {Vaeßen, Christiane and Alexopoulos, Spiros and Kluczka, Sven and Sattler, Johannes Christoph and Roeb, M. and Neises, M. and Abdellatif, T.},
  title     = {Analyse der Verfahren zur solaren Methanolproduktion aus CO2},
  series = {Forschung und Entwicklung f{\"u}r solarthermische Kraftwerke : 14. K{\"o}lner Sonnenkolloquium Mittwoch, 13. Juli 2011, im Auditorium des Campus J{\"u}lich der FH Aachen : Kurzfassungen der Vortr{\"a}ge und Poster},
  booktitle = {Forschung und Entwicklung f{\"u}r solarthermische Kraftwerke : 14. K{\"o}lner Sonnenkolloquium Mittwoch, 13. Juli 2011, im Auditorium des Campus J{\"u}lich der FH Aachen : Kurzfassungen der Vortr{\"a}ge und Poster},
  publisher = {DLR},
  address   = {K{\"o}ln},
  pages     = {2 S.},
  year      = {2011},
  language  = {de}
}
@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{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{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{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{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}
}
@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}
}