@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} } @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} } @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{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{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{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} } @incollection{AtmaneHirechKassmietal.2020, author = {Atmane, Ilias and Hirech, Kamal and Kassmi, K. and Mahdi, Zahra and Alexopoulos, Spiros and Schwarzer, Klemens and Chayeb, H. and Bachiri, N.}, title = {Design and realization of a pilot solar desalination plant in Douar El Hamri in the province of Berkane (Morocco)}, series = {Sustainable entrepreneurship, renewable energy-based projects, and digitalization}, booktitle = {Sustainable entrepreneurship, renewable energy-based projects, and digitalization}, editor = {Omrane, Amina and Kassmi, Khalil and Akram, Muhammad Wasim and Khanna, Ashish and Mostafiz, Imtiaz}, publisher = {CRC Press}, address = {Boca Raton, Fa.}, isbn = {9781000292541 (E-Book)}, pages = {18 Seiten}, year = {2020}, abstract = {Producing fresh water from saline water has become one of the most difficult challenges to overcome especially with the high demand and shortage of fresh water. In this context, as part of a collaboration with Germany, the authors propose a design and implementation of a pilot multi-stage solar desalination system (MSD), remotely controlled, at Douar Al Hamri in the rural town of Boughriba in the province of Berkane, Morocco. More specifically, they present their contribution on the remote control and supervision system, which makes the functioning of the MSD system reliable and guarantees the production of drinking water for the population of Douar. The results obtained show that the electronic cards and computer communication software implemented allow the acquisition of all electrical (currents, voltages, powers, yields), thermal (temperatures of each stage), and meteorological (irradiance and ambient temperature), remote control and maintenance (switching on, off, data transfer). By comparing with the literature carried out in the field of solar energy, the authors conclude that the MSD and electronic desalination systems realized during this work represent a contribution in terms of the reliability and durability of providing drinking water in rural and urban areas.}, language = {en} } @inproceedings{SattlerChicoCaminosUerlingsetal.2020, author = {Sattler, Johannes Christoph and Chico Caminos, Ricardo Alexander and {\"U}rlings, Nicolas and Dutta, Siddharth and Ruiz, Victor and Kalogirou, Soteris and Ktistis, Panayiotis and Agathokleous, Rafaela and Jung, Christian and Alexopoulos, Spiros and Atti, Vikrama Naga Babu and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Operational experience and behaviour of a parabolic trough collector system with concrete thermal energy storage for process steam generation in Cyprus}, series = {AIP Conference Proceedings}, booktitle = {AIP Conference Proceedings}, number = {2303}, doi = {10.1063/5.0029278}, pages = {140004-1 -- 140004-10}, year = {2020}, abstract = {As part of the transnational research project EDITOR, a parabolic trough collector system (PTC) with concrete thermal energy storage (C-TES) was installed and commissioned in Limassol, Cyprus. The system is located on the premises of the beverage manufacturer KEAN Soft Drinks Ltd. and its function is to supply process steam for the factory's pasteurisation process [1]. Depending on the factory's seasonally varying capacity for beverage production, the solar system delivers between 5 and 25 \% of the total steam demand. In combination with the C-TES, the solar plant can supply process steam on demand before sunrise or after sunset. Furthermore, the C-TES compensates the PTC during the day in fluctuating weather conditions. The parabolic trough collector as well as the control and oil handling unit is designed and manufactured by Protarget AG, Germany. The C-TES is designed and produced by CADE Soluciones de Ingenier{\´i}a, S.L., Spain. In the focus of this paper is the description of the operational experience with the PTC, C-TES and boiler during the commissioning and operation phase. Additionally, innovative optimisation measures are presented.}, language = {en} }