@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{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} } @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} } @article{GoettscheRuss2005, author = {G{\"o}ttsche, Joachim and Russ, Christel}, title = {Energieversorgung in Niedrigstenergie-Neubauwohnungen / Christel Russ ; Joachim G{\"o}ttsche}, series = {W{\"a}rme und K{\"a}lte - Energie aus Sonne und Erde : Jahrestagung des Forschungsverbunds Sonnenenergie in Kooperation mit der Landesinitiative Zukunftsenergie NRW / Stadermann, Gerd, Hrsg.}, journal = {W{\"a}rme und K{\"a}lte - Energie aus Sonne und Erde : Jahrestagung des Forschungsverbunds Sonnenenergie in Kooperation mit der Landesinitiative Zukunftsenergie NRW / Stadermann, Gerd, Hrsg.}, publisher = {Forschungsverbund Sonnenenergie}, address = {Berlin}, pages = {93 -- 98}, year = {2005}, language = {de} } @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} } @article{GoettscheHinschWittwer1993, author = {G{\"o}ttsche, Joachim and Hinsch, Andreas and Wittwer, Volker}, title = {Electrochromic mixed WO3-TiO2 thin films produced by sputtering and the sol-gel technique : a comparison / J. G{\"o}ttsche ; A. Hinsch ; V. Wittwer}, series = {Solar Energy Materials and Solar Cells. 31 (1993), H. 3}, journal = {Solar Energy Materials and Solar Cells. 31 (1993), H. 3}, isbn = {0927-0248}, pages = {415 -- 428}, year = {1993}, language = {en} } @article{GoettscheTammeNunez2005, author = {G{\"o}ttsche, Joachim and Tamme, Rainer and Nunez, Thomas}, title = {Speicherung f{\"u}r Hochtemperaturw{\"a}rme / Rainer Tamme ; Joachim G{\"o}ttsche ; Thomas Nunez}, series = {W{\"a}rme und K{\"a}lte - Energie aus Sonne und Erde : Jahrestagung des Forschungsverbunds Sonnenenergie in Kooperation mit der Landesinitiative Zukunftsenergie NRW / Stadermann, Gerd, Hrsg.}, journal = {W{\"a}rme und K{\"a}lte - Energie aus Sonne und Erde : Jahrestagung des Forschungsverbunds Sonnenenergie in Kooperation mit der Landesinitiative Zukunftsenergie NRW / Stadermann, Gerd, Hrsg.}, publisher = {Forschungsverbund Sonnenenergie}, address = {Berlin}, pages = {126 -- 131}, year = {2005}, language = {de} } @article{HerrmannKellyPrice2002, author = {Herrmann, Ulf and Kelly, Bruce and Price, Henry}, title = {Two Tank Molten Salt Storage for Parabolic Trough Solar Power Plants}, series = {Energy : the international journal}, volume = {29}, journal = {Energy : the international journal}, number = {5-6 (Special Issue SolarPaces)}, issn = {0360-5442}, doi = {10.1016/S0360-5442(03)00193-2}, pages = {883 -- 893}, year = {2002}, language = {en} } @article{HerrmannSchwarzenbartDittmannGabrieletal.2019, author = {Herrmann, Ulf and Schwarzenbart, Marc and Dittmann-Gabriel, S{\"o}ren and May, Martin}, title = {Hochtemperatur-W{\"a}rmespeicher f{\"u}r die Strom- und W{\"a}rmewende}, series = {Solarzeitalter : Politik, Kultur und {\"O}konomie erneuerbarer Energien}, volume = {31}, journal = {Solarzeitalter : Politik, Kultur und {\"O}konomie erneuerbarer Energien}, number = {2}, issn = {0937-3802}, pages = {18 -- 23}, year = {2019}, language = {de} } @article{DerschGeyerHerrmannetal.2004, author = {Dersch, J{\"u}rgen and Geyer, Michael and Herrmann, Ulf and Jones, Scott A. and Kelly, Bruce and Kistner, Rainer and Ortmanns, Winfried and Pitz-Paal, Robert and Price, Henry}, title = {Trough integration into power plants—a study on the performance and economy of integrated solar combined cycle systems}, series = {Energy : the international journal}, volume = {29}, journal = {Energy : the international journal}, number = {5-6 (Special Issue SolarPaces)}, issn = {0360-5442}, doi = {10.1016/S0360-5442(03)00199-3}, pages = {947 -- 959}, year = {2004}, 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} } @article{GorzalkaSchmiedtSchorn2021, author = {Gorzalka, Philip and Schmiedt, Jacob Estevam and Schorn, Christian}, title = {Automated Generation of an Energy Simulation Model for an Existing Building from UAV Imagery}, series = {Buildings}, volume = {11}, journal = {Buildings}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2075-5309}, doi = {10.3390/buildings11090380}, pages = {15 Seiten}, year = {2021}, abstract = {An approach to automatically generate a dynamic energy simulation model in Modelica for a single existing building is presented. It aims at collecting data about the status quo in the preparation of energy retrofits with low effort and costs. The proposed method starts from a polygon model of the outer building envelope obtained from photogrammetrically generated point clouds. The open-source tools TEASER and AixLib are used for data enrichment and model generation. A case study was conducted on a single-family house. The resulting model can accurately reproduce the internal air temperatures during synthetical heating up and cooling down. Modelled and measured whole building heat transfer coefficients (HTC) agree within a 12\% range. A sensitivity analysis emphasises the importance of accurate window characterisations and justifies the use of a very simplified interior geometry. Uncertainties arising from the use of archetype U-values are estimated by comparing different typologies, with best- and worst-case estimates showing differences in pre-retrofit heat demand of about ±20\% to the average; however, as the assumptions made are permitted by some national standards, the method is already close to practical applicability and opens up a path to quickly estimate possible financial and energy savings after refurbishment.}, language = {en} } @article{SattlerRoegerSchwarzboezletal.2020, author = {Sattler, Johannes Christoph and R{\"o}ger, Marc and Schwarzb{\"o}zl, Peter and Buck, Reiner and Macke, Ansgar and Raeder, Christian and G{\"o}ttsche, Joachim}, title = {Review of heliostat calibration and tracking control methods}, series = {Solar Energy}, volume = {207}, journal = {Solar Energy}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.solener.2020.06.030}, pages = {110 -- 132}, year = {2020}, abstract = {Large scale central receiver systems typically deploy between thousands to more than a hundred thousand heliostats. During solar operation, each heliostat is aligned individually in such a way that the overall surface normal bisects the angle between the sun's position and the aim point coordinate on the receiver. Due to various tracking error sources, achieving accurate alignment ≤1 mrad for all the heliostats with respect to the aim points on the receiver without a calibration system can be regarded as unrealistic. Therefore, a calibration system is necessary not only to improve the aiming accuracy for achieving desired flux distributions but also to reduce or eliminate spillage. An overview of current larger-scale central receiver systems (CRS), tracking error sources and the basic requirements of an ideal calibration system is presented. Leading up to the main topic, a description of general and specific terms on the topics heliostat calibration and tracking control clarifies the terminology used in this work. Various figures illustrate the signal flows along various typical components as well as the corresponding monitoring or measuring devices that indicate or measure along the signal (or effect) chain. The numerous calibration systems are described in detail and classified in groups. Two tables allow the juxtaposition of the calibration methods for a better comparison. In an assessment, the advantages and disadvantages of individual calibration methods are presented.}, language = {en} } @article{GoettscheHoffschmidtSchmitzetal.2009, author = {G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Sauerborn, Markus}, title = {Solar Concentrating Systems Using Small Mirror Arrays / G{\"o}ttsche, Joachim ; Hoffschmidt, Bernhard ; Schmitz, Stefan ; Sauerborn, Markus ; Buck, Reiner ; Teufel, Edgar ; Badst{\"u}bner, Karin ; Ifland, David ; Rebholz, Christian}, series = {Proceedings of the 2nd International Conference on Energy Sustainability - 2008 : : presented ... August 10 - 14, 2008, Jacksonville, Florida, USA / sponsored by Advanced Energy Systems Division, ASME; Solar Energy Division, ASME}, journal = {Proceedings of the 2nd International Conference on Energy Sustainability - 2008 : : presented ... August 10 - 14, 2008, Jacksonville, Florida, USA / sponsored by Advanced Energy Systems Division, ASME; Solar Energy Division, ASME}, publisher = {ASME}, address = {New York, NY}, isbn = {9780791843208}, pages = {1 -- 5}, year = {2009}, language = {en} } @article{GoettscheHoffschmidtSchmitzetal.2010, author = {G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Sauerborn, Markus}, title = {Solar Concentrating Systems Using Small Mirror Arrays}, series = {Journal of solar energy engineering}, volume = {Vol. 132}, journal = {Journal of solar energy engineering}, number = {Iss. 1}, isbn = {0199-6231}, pages = {4 S.}, year = {2010}, 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{GoettscheGabryschSchilleretal.2006, author = {G{\"o}ttsche, Joachim and Gabrysch, K. and Schiller, H. and Schwarzer, Klemens}, title = {Energetische Sanierung eines biochemischen Laborgeb{\"a}udes : Auswirkung bedarfsabh{\"a}ngiger L{\"u}ftung mit W{\"a}rmer{\"u}ckgewinnung auf den Prim{\"a}renergieverbrauch}, series = {Heizungs- und Raumlufttechnik : 1. Fachtagung Leonberg, 31. Januar bis 1. Februar 2006 / VDI-Tage der Geb{\"a}udetechnik. VDI-Gesellschaft Technische Geb{\"a}udeausr{\"u}stung}, journal = {Heizungs- und Raumlufttechnik : 1. Fachtagung Leonberg, 31. Januar bis 1. Februar 2006 / VDI-Tage der Geb{\"a}udetechnik. VDI-Gesellschaft Technische Geb{\"a}udeausr{\"u}stung}, publisher = {VDI-Verl.}, address = {D{\"u}sseldorf}, isbn = {3-18-091921-3}, pages = {221 -- 230}, year = {2006}, language = {de} } @article{HerrmannSchwarzenbartDittmannGabriel2019, author = {Herrmann, Ulf and Schwarzenbart, Marc and Dittmann-Gabriel, S{\"o}ren}, title = {Speicher statt Kohle. Integration thermischer Stromspeicher in vorhandene Kraftwerksstandorte}, series = {BWK : Das Energie-Fachmagazin}, volume = {71}, journal = {BWK : Das Energie-Fachmagazin}, number = {4}, publisher = {Springer-VDI-Verl.}, address = {D{\"u}sseldorf}, issn = {1436-4883}, pages = {42 -- 45}, year = {2019}, language = {de} } @article{HenneckeSchwarzboezlHoffschmidtetal.2007, author = {Hennecke, Klaus and Schwarzb{\"o}zl, Peter and Hoffschmidt, Bernhard and G{\"o}ttsche, Joachim and Koll, G. and Beuter, M. and Hartz, T.}, title = {The solar power tower J{\"u}lich - a solar thermal power plant for test and demonstration of air receiver}, series = {Solar energy and human settlement : Elektronische Ressource : proceedings of ISES world congress 2007 ; (Vol. I - Vol. V) / [ISES Solar World Congress. ISES, International Solar Energy Society]. D. Yogi Goswami ; Yuwen Zhao}, journal = {Solar energy and human settlement : Elektronische Ressource : proceedings of ISES world congress 2007 ; (Vol. I - Vol. V) / [ISES Solar World Congress. ISES, International Solar Energy Society]. D. Yogi Goswami ; Yuwen Zhao}, publisher = {Tsinghua Univ. Press}, address = {Beijing}, isbn = {978-7-302-16146-2}, pages = {1749 -- 1753}, year = {2007}, language = {en} } @article{KearneyHerrmannNavaetal.2003, author = {Kearney, D. and Herrmann, Ulf and Nava, P. and Kelly, B. and Mahoney, R. and Pacheco, J. and Cable, R. and Potrovitza, N. and Blake, D. and Price, H.}, title = {Assessment of a Molten Salt Heat Transfer Fluid in a Parabolic Trough Solar Field}, series = {Journal of Solar Energy Engineering}, volume = {125}, journal = {Journal of Solar Energy Engineering}, number = {2}, issn = {1528-8986}, doi = {10.1115/1.1565087}, pages = {170 -- 176}, year = {2003}, language = {en} }