TY - JOUR A1 - Alexopoulos, Spiros A1 - Hoffschmidt, Bernhard T1 - Advances in solar tower technology JF - Wiley interdisciplinary reviews : Energy and Environment : WIREs Y1 - 2017 U6 - http://dx.doi.org/10.1002/wene.217 SN - 2041-840X VL - 6 IS - 1 SP - 1 EP - 19 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Vaeßen, Christiane A1 - Alexopoulos, Spiros A1 - Kluczka, Sven A1 - Sattler, Johannes Christoph A1 - Roeb, M. A1 - Neises, M. A1 - Abdellatif, T. T1 - Analyse der Verfahren zur solaren Methanolproduktion aus CO2 T2 - Forschung und Entwicklung für solarthermische Kraftwerke : 14. Kölner Sonnenkolloquium Mittwoch, 13. Juli 2011, im Auditorium des Campus Jülich der FH Aachen : Kurzfassungen der Vorträge und Poster Y1 - 2011 SP - 2 S. PB - DLR CY - Köln ER - TY - CHAP A1 - Breitbach, Gerd A1 - Alexopoulos, Spiros A1 - May, Martin A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Analysis of volumetric solar radiation absorbers made of wire meshes T2 - AIP Conference Proceedings Y1 - 2019 U6 - http://dx.doi.org/10.1063/1.5117521 SN - 0094243X VL - 2126 SP - 030009-1 EP - 030009-6 ER - TY - JOUR A1 - Alexopoulos, Spiros T1 - Biogas systems: basics, biogas multifunction, principle of fermentation and hybrid application with a solar tower for the treatment of waste animal manure JF - Journal of Engineering Science and Technology Review N2 - 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 Y1 - 2012 SN - 1791-2377 N1 - Special Issue on Renewable Energy Systems VL - 5 IS - 4 SP - 48 EP - 55 ER - TY - CHAP A1 - Alexopoulos, Spiros T1 - Biomass technology and bio-fuels: Heating/cooling and power T2 - Renewable energy systems : theory, innovations, and intelligent applications / eds.: Socrates Kaplanis and Eleni Kaplani Y1 - 2013 SN - 9781624177415 SP - 501 EP - 523 PB - Nova Science Publ. CY - Hauppauge, NY ER - TY - CHAP A1 - Alexopoulos, Spiros A1 - Hoffschmidt, Bernhard A1 - Rau, Christoph A1 - Sattler, Johannes, Christoph T1 - Choice of solar share of a hybrid power plant of a central receiver system and a biogas plant in dependency of the geographical latitude T2 - World Renewable Energy Congress-Sweden : 8 -13 May, 2011, Linköping, Sweden / ed.: Bahram Moshfegh Y1 - 2011 SN - 9789173930703 SP - 3710 EP - 3717 PB - Univ. Electronic Pr. CY - Linköping ER - TY - CHAP A1 - Latzke, Markus A1 - Alexopoulos, Spiros A1 - Kronhardt, Valentina A1 - Rendón, Carlos A1 - Sattler, Johannes, Christoph T1 - Comparison of Potential Sites in China for Erecting a Hybrid Solar Tower Power Plant with Air Receiver T2 - Energy Procedia Y1 - 2015 U6 - http://dx.doi.org/10.1016/j.egypro.2015.03.142 SN - 1876-6102 N1 - International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2014, Beijing, China SP - 1327 EP - 1334 ER - TY - CHAP A1 - Alexopoulos, Spiros A1 - Hoffschmidt, Bernhard A1 - Rau, Christoph T1 - Comparison of steady-state and transient simulations for solar tower power plants with open-volumetric receiver T2 - SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain Y1 - 2011 CY - Granada ER - TY - JOUR A1 - Alexopoulos, Spiros A1 - Breitbach, Gerd A1 - Hoffschmidt, Bernhard A1 - Stobbe, P. T1 - Computational fluid flow of porous resic ceramic filtering modules and optimization of the channel edge form geometry JF - Proceedings : April 14 - 18, 2008, Leipzig, Germany / hosted by VDI, Society for Chemical and Process Engineering . Vol 2 Y1 - 2008 N1 - Verein Deutscher Ingenieure ; World Filtration Congress ; (10 : ; 2008.04.14-18 : ; Leipzig) ; WFC ; (10 : ; 2008.04.14-18 : ; Leipzig) SP - 300 EP - 304 PB - Filtech Exhibitions CY - Meerbusch ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Rau, Christoph A1 - Sattler, Johannes, Christoph A1 - Anthrakidis, Anette A1 - Teixeira Boura, Cristiano José A1 - O'Connor, P. A1 - Hilger, Patrick T1 - Concentrating solar power T2 - Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications Y1 - 2012 SN - 978-0-08-087872-0 U6 - http://dx.doi.org/10.1016/B978-0-08-087872-0.00319-X VL - 3 SP - 595 EP - 636 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Rau, Christoph A1 - Sattler, Johannes, Christoph A1 - Anthrakidis, Anette A1 - Teixeira Boura, Cristiano José A1 - O’Connor, B. A1 - Caminos, R.A. Chico A1 - Rendón, C. A1 - Hilger, P. T1 - Concentrating Solar Power T2 - Earth systems and environmental sciences N2 - 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. KW - Central receiver power plant KW - Concentrated systems KW - Concentrating solar power KW - Fresnel power plant KW - Gas turbine Y1 - 2021 SN - 978-0-12-409548-9 U6 - http://dx.doi.org/10.1016/B978-0-12-819727-1.00089-3 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Rau, Christoph A1 - Sattler, Johannes, Christoph A1 - Anthrakidis, Anette A1 - Teixeira Boura, Cristiano José A1 - O’Connor, B. A1 - Chico Caminos, R.A. A1 - Rendón, C. A1 - Hilger, P. T1 - Concentrating solar power T2 - Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications N2 - 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. KW - Central receiver power plant KW - Concentrated systems KW - Gas turbine KW - Hybridization KW - Power conversion systems Y1 - 2022 SN - 978-0-12-819734-9 SP - 670 EP - 724 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Sattler, Johannes Christoph A1 - Atti, Vikrama A1 - Alexopoulos, Spiros A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf A1 - Dutta, Siddharth A1 - Kioutsioukis, Ioannis T1 - DNI forecast tool for the smart operation of a parabolic trough collector system with concrete thermal energy storage: Theory, results and outlook T2 - SolarPACES conference proceedings N2 - This work presents a basic forecast tool for predicting direct normal irradiance (DNI) in hourly resolution, which the Solar-Institut Jülich (SIJ) is developing within a research project. The DNI forecast data shall be used for a parabolic trough collector (PTC) system with a concrete thermal energy storage (C-TES) located at the company KEAN Soft Drinks Ltd in Limassol, Cyprus. On a daily basis, 24-hour DNI prediction data in hourly resolution shall be automatically produced using free or very low-cost weather forecast data as input. The purpose of the DNI forecast tool is to automatically transfer the DNI forecast data on a daily basis to a main control unit (MCU). The MCU automatically makes a smart decision on the operation mode of the PTC system such as steam production mode and/or C-TES charging mode. The DNI forecast tool was evaluated using historical data of measured DNI from an on-site weather station, which was compared to the DNI forecast data. The DNI forecast tool was tested using data from 56 days between January and March 2022, which included days with a strong variation in DNI due to cloud passages. For the evaluation of the DNI forecast reliability, three categories were created and the forecast data was sorted accordingly. The result was that the DNI forecast tool has a reliability of 71.4 % based on the tested days. The result fulfils SIJ’s aim to achieve a reliability of around 70 %, but SIJ aims to still improve the DNI forecast quality. KW - Direct normal irradiance forecast KW - DNI forecast KW - Parabolic trough collector KW - PTC KW - Thermal Energy Storage Y1 - 2024 U6 - http://dx.doi.org/10.52825/solarpaces.v1i.731 SN - 2751-9899 (online) N1 - 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA IS - VOL. 1 PB - TIB Open Publishing CY - Hannover ER - TY - CHAP A1 - Sattler, Johannes, Christoph A1 - Alexopoulos, Spiros A1 - Caminos, Ricardo Alexander Chico A1 - Mitchell, John C. A1 - Ruiz, Victor C. A1 - Kalogirou, Soteris A1 - Ktistis, Panayiotis K. A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Dynamic simulation model of a parabolic trough collector system with concrete thermal energy storage for process steam generation T2 - AIP Conference Proceedings Y1 - 2019 U6 - http://dx.doi.org/10.1063/1.5117663 SN - 0094243X VL - 2126 SP - 150007-1 EP - 150007-8 ER - TY - CHAP A1 - Sattler, Johannes Christoph A1 - Chico Caminos, Ricardo Alexander A1 - Atti, Vikrama Nagababu A1 - Ürlings, Nicolas A1 - Dutta, Siddharth A1 - Ruiz, Victor A1 - Kalogirou, Soteris A1 - Ktistis, Panayiotis A1 - Agathokleous, Rafaela A1 - Alexopoulos, Spiros A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Dynamic simulation tool for a performance evaluation and sensitivity study of a parabolic trough collector system with concrete thermal energy storage T2 - AIP Conference Proceedings 2303 Y1 - 2020 U6 - http://dx.doi.org/10.1063/5.0029277 SN - 0094-243X SP - 160004 PB - American Institute of Physics CY - Melville, NY ER - TY - RPRT A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros T1 - Entwicklung der Designvoraussetzungen für ein hybrides Solarthermisches Kraftwerk : Kurztitel: HybSol ; Abschlussbericht ; Berichtszeitraum: 01.03.2007 - 31.10.2010 ; [Förderprogramm: FHprofUnt] Y1 - 2011 PB - Solar-Inst. CY - Jülich ER - TY - CHAP A1 - May, Martin A1 - Breitbach, Gerd A1 - Alexopoulos, Spiros A1 - Latzke, Markus A1 - Bäumer, Klaus A1 - Uhlig, Ralf A1 - Söhn, Matthias A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Experimental facility for investigations of wire mesh absorbers for pressurized gases T2 - AIP Conference Proceedings Y1 - 2019 U6 - http://dx.doi.org/10.1063/1.5117547 SN - 0094243X VL - 2126 SP - 030035-1 EP - 030035-9 ER - TY - JOUR A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Funke, J. A1 - Schwarzbözl, P. T1 - First Simulation Results for the Hybridization of Small Solar Power Tower Plants JF - EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings, 2008-10-07 - 2008-10-10, Lissabon (Portugal). Vol. 1 Y1 - 2008 SN - 978-1-61782-228-5 N1 - Kurzfassung unter http://elib.dlr.de/56357/ SP - 1299 EP - 1306 PB - Sociedade Portuguesa De Energia Solar (SPES) CY - Lisbon ER - TY - CHAP A1 - Breitbach, Gerd A1 - Alexopoulos, Spiros A1 - Hoffschmidt, Bernhard T1 - Fluid flow in porous ceramic multichannel crossflower filter modules Y1 - 2007 PB - COMSOL Inc. CY - Burlington, Mass. ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Göttsche, Joachim A1 - Sauerborn, Markus T1 - High concentration solar collectors T2 - Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications N2 - 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. KW - Central receiver system KW - Concentrated solar collector KW - Fresnel collector KW - Optical and thermal analysis KW - Solar concentration Y1 - 2012 SN - 978-0-08-087873-7 U6 - http://dx.doi.org/10.1016/B978-0-08-087872-0.00306-1 VL - 3 SP - 165 EP - 209 PB - Elsevier CY - Amsterdam ER -