TY - JOUR A1 - Göttsche, Joachim A1 - Goetzberger, Adolf A1 - Dengler, J. A1 - Rommel, M. (u.a.) T1 - A new transparently insulated, bifacially irradiated solar flat-plate collector / A. Goetzberger ; J. Dengler ; M. Rommel ; J. Göttsche ; V. Wittwer JF - Solar energy. 49 (1992), H. 5 Y1 - 1992 SN - 0038-092X SP - 403 EP - 411 ER - TY - JOUR A1 - Schwager, Christian A1 - Flesch, Robert A1 - Schwarzbözl, Peter A1 - Herrmann, Ulf A1 - Teixeira Boura, Cristiano José T1 - Advanced two phase flow model for transient molten salt receiver system simulation JF - Solar Energy N2 - In order to realistically predict and optimize the actual performance of a concentrating solar power (CSP) plant sophisticated simulation models and methods are required. This paper presents a detailed dynamic simulation model for a Molten Salt Solar Tower (MST) system, which is capable of simulating transient operation including detailed startup and shutdown procedures including drainage and refill. For appropriate representation of the transient behavior of the receiver as well as replication of local bulk and surface temperatures a discretized receiver model based on a novel homogeneous two-phase (2P) flow modelling approach is implemented in Modelica Dymola®. This allows for reasonable representation of the very different hydraulic and thermal properties of molten salt versus air as well as the transition between both. This dynamic 2P receiver model is embedded in a comprehensive one-dimensional model of a commercial scale MST system and coupled with a transient receiver flux density distribution from raytracing based heliostat field simulation. This enables for detailed process prediction with reasonable computational effort, while providing data such as local salt film and wall temperatures, realistic control behavior as well as net performance of the overall system. Besides a model description, this paper presents some results of a validation as well as the simulation of a complete startup procedure. Finally, a study on numerical simulation performance and grid dependencies is presented and discussed. KW - Molten salt solar tower KW - Molten salt receiver system KW - Dynamic simulation KW - Two-phase modelling KW - Transient flux distribution Y1 - 2022 U6 - http://dx.doi.org/10.1016/j.solener.2021.12.065 SN - 0038-092X (print) SN - 1471-1257 (online) VL - 232 SP - 362 EP - 375 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Göttsche, Joachim A1 - Reilly, S. A1 - Wittwer, Volker T1 - Advanced window systems and building energy performance / S. Reilly ; J. Göttsche ; V. Wittwer JF - Solar World Congress, 1991 : proceedings of the biennial congress of the International Solar Energy Society, Denver, Colorado, USA, 19-23 August 1991 / ed. by M. E. Arden ... Y1 - 1991 SN - 0-08-041690-X SP - 3211 EP - 3216 PB - Pergamon Press CY - Oxford [u.a.] ER - 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 - JOUR A1 - Kearney, D. A1 - Herrmann, Ulf A1 - Nava, P. A1 - Kelly, B. A1 - Mahoney, R. A1 - Pacheco, J. A1 - Cable, R. A1 - Potrovitza, N. A1 - Blake, D. A1 - Price, H. T1 - Assessment of a Molten Salt Heat Transfer Fluid in a Parabolic Trough Solar Field JF - Journal of Solar Energy Engineering Y1 - 2003 U6 - http://dx.doi.org/10.1115/1.1565087 SN - 1528-8986 VL - 125 IS - 2 SP - 170 EP - 176 ER - TY - JOUR A1 - Gorzalka, Philip A1 - Schmiedt, Jacob Estevam A1 - Schorn, Christian T1 - Automated Generation of an Energy Simulation Model for an Existing Building from UAV Imagery JF - Buildings N2 - 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. KW - Modelica KW - heat transfer coefficient KW - heat demand KW - building energy modelling KW - building energy simulation Y1 - 2021 U6 - http://dx.doi.org/10.3390/buildings11090380 SN - 2075-5309 N1 - This article belongs to the Special Issue "Application of Computer Technology in Buildings" VL - 11 IS - 9 PB - MDPI CY - Basel 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 - JOUR A1 - Wolisz, Henryk A1 - Schütz, Thomas A1 - Blanke, Tobias A1 - Hagenkamp, Markus A1 - Kohrn, Markus A1 - Wesseling, Mark A1 - Müller, Dirk T1 - Cost optimal sizing of smart buildings' energy system components considering changing end-consumer electricity markets JF - Energy Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.energy.2017.06.025 VL - 137 SP - 715 EP - 728 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Göttsche, Joachim A1 - Schwarzer, Klemens A1 - Röther, S. A1 - Jellinghaus, Sabine T1 - Efficient daylighting, heating and shading with rooflight heliostats JF - Conference Internationale Energie Solaire et Batiment Y1 - 2009 SP - 243 EP - 248 PB - EPFL CY - Lausanne ER - TY - JOUR A1 - Göttsche, Joachim T1 - Eldorado summer schools JF - Progress in solar energy education. 3 (1994) Y1 - 1994 SN - 1018-5607 SP - 31 EP - 33 ER - TY - JOUR A1 - Göttsche, Joachim A1 - Hinsch, Andreas A1 - Wittwer, Volker T1 - Electrochromic mixed WO3-TiO2 thin films produced by sputtering and the sol-gel technique : a comparison / J. Göttsche ; A. Hinsch ; V. Wittwer JF - Solar Energy Materials and Solar Cells. 31 (1993), H. 3 Y1 - 1993 SN - 0927-0248 SP - 415 EP - 428 ER - TY - JOUR A1 - Göttsche, Joachim A1 - Gabrysch, K. A1 - Schiller, H. A1 - Kauert, B. A1 - Schwarzer, Klemens T1 - Energetic Effects of demand – controlled ventilation retrofitting in a biochemical laboratory building JF - AIVC publications [Elektronische Ressource] / Air Infiltration and Ventilation Centre Y1 - 2004 N1 - AIVC Conference <25, Prague, 2004> SP - 50 PB - INIVE EEIG CY - Brussels ER - TY - JOUR A1 - Kearney, David W. A1 - Kelly, Bruce A1 - Herrmann, Ulf A1 - Cable, R. A1 - Pacheco, J. A1 - Mahoney, R. A1 - Price, Henry A1 - Blake, D. A1 - Nava, P. A1 - Potrovitza, N. T1 - Engineering Aspects of a Molten Salt Heat Transfer Fluid in a Trough Solar Field JF - Energy : the international journal Y1 - 2002 U6 - http://dx.doi.org/10.1016/S0360-5442(03)00191-9 SN - 0360-5442 N1 - SolarPACES 2002, Zürich, Switzerland, 4–6 September 2002 VL - 29 IS - 5-6 (Special Issue SolarPaces) SP - 861 EP - 870 ER - TY - JOUR A1 - Agrafiotis, Christos C. A1 - Mavroidis, Ilias A1 - Konstandopoulos, Athansios G. A1 - Hoffschmidt, Bernhard A1 - Stobbe, Per A1 - Romero, Manuel A1 - Fernandez-Quero, Valerio T1 - Evaluation of porous silicon carbide monolithic honeycombs as volumetric receivers/collectors of concentrated solar radiation JF - Solar energy materials and solar cells Y1 - 2007 SN - 1879-3398 (E-Journal); 0927-0248 (Print) VL - Vol. 91 IS - Iss. 6 SP - 474 EP - 488 ER - TY - JOUR A1 - El Moussaoui, Noureddine A1 - Talbi, Sofian A1 - Atmane, Ilyas A1 - Kassmi, Khalil A1 - Schwarzer, Klemens A1 - Chayeb, Hamid A1 - Bachiri, Najib T1 - Feasibility of a new design of a Parabolic Trough Solar Thermal Cooker (PSTC) JF - Solar Energy N2 - In this article, we describe the structure, the functioning, and the tests of parabolic trough solar thermal cooker (PSTC). This oven is designed to meet the needs of rural residents, including Urban, which requires stable cooking temperatures above 200 °C. The cooking by this cooker is based on the concentration of the sun's rays on a glass vacuum tube and heating of the oil circulate in a big tube, located inside the glass tube. Through two small tubes, associated with large tube, the heated oil, rise and heats the pot of cooking pot containing the food to be cooked (capacity of 5 kg). This cooker is designed in Germany and extensively tested in Morocco for use by the inhabitants who use wood from forests. During a sunny day, having a maximum solar radiation around 720 W/m2 and temperature ambient around 26 °C, maximum temperatures recorded of the small tube, the large tube and the center of the pot are respectively: 370 °C, 270 °C and 260 °C. The cooking process with food at high (fries, ..), we show that the cooking oil temperature rises to 200 °C, after 1 h of heating, the cooking is done at a temperature of 120 °C for 20 min. These temperatures are practically stable following variations and decreases in the intensity of irradiance during the day. The comparison of these results with those of the literature shows an improvement of 30–50 % on the maximum value of the temperature with a heat storage that could reach 60 min of autonomy. All the results obtained show the good functioning of the PSTC and the feasibility of cooking food at high temperature (>200 °C). Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.solener.2020.03.079 SN - 0038-092X VL - 201 IS - Vol. 201 (May 2020) SP - 866 EP - 871 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Vieira da Silva, Maria Eugenia A1 - Schwarzer, Tarik T1 - Field results in Namibia and Brazil of the new solar desalination system for decentralised drinking water production JF - Desalination and water treatment. Vol. 31 (2011), iss. 1-3: selected papers presented at EuroMed 2010 — Desalination for Clean Water and Energy: Cooperation among Mediterranean Countries of Europe and MENA Region, 3–7 October 2010, Tel Aviv, Israel Y1 - 2011 SP - 379 EP - 386 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 - JOUR A1 - Peere, Wouter A1 - Blanke, Tobias ED - Vernon, Chris T1 - GHEtool: An open-source tool for borefield sizing in Python JF - Journal of Open Source Software N2 - GHEtool is a Python package that contains all the functionalities needed to deal with borefield design. It is developed for both researchers and practitioners. The core of this package is the automated sizing of borefield under different conditions. The sizing of a borefield is typically slow due to the high complexity of the mathematical background. Because this tool has a lot of precalculated data, GHEtool can size a borefield in the order of tenths of milliseconds. This sizing typically takes the order of minutes. Therefore, this tool is suited for being implemented in typical workflows where iterations are required. GHEtool also comes with a graphical user interface (GUI). This GUI is prebuilt as an exe-file because this provides access to all the functionalities without coding. A setup to install the GUI at the user-defined place is also implemented and available at: https://www.mech.kuleuven.be/en/tme/research/thermal_systems/tools/ghetool. KW - geothermal KW - energy KW - borefields KW - sizing Y1 - 2022 U6 - http://dx.doi.org/10.21105/joss.04406 SN - 2475-9066 VL - 7 IS - 76 SP - 1 EP - 4, 4406 ER - TY - JOUR A1 - Velraj, R. A1 - Seeniraj, R. V. A1 - Hafner, B. A1 - Faber, Christian A1 - Schwarzer, Klemens T1 - Heat transfer enhancement in a latent heat storage system JF - Solar energy. Vol. 65, iss. 3 Y1 - 1999 SN - 0038-092X SP - 171 EP - 180 ER - TY - JOUR A1 - Kronhardt, Valentina A1 - Alexopoulos, Spiros A1 - Reißel, Martin A1 - Sattler, Johannes, Christoph A1 - Hoffschmidt, Bernhard A1 - Hänel, Matthias A1 - Doerbeck, Till T1 - High-temperature thermal storage system for solar tower power plants with open-volumetric air receiver simulation and energy balancing of a discretized model JF - Energy procedia N2 - 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. Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.egypro.2014.03.094 SN - 1876-6102 (E-Journal) ; 1876-6102 (Print) VL - 49 SP - 870 EP - 877 PB - Elsevier CY - Amsterdam ER -