TY - CHAP A1 - Blanke, Tobias A1 - Schmidt, Katharina S. A1 - Göttsche, Joachim A1 - Döring, Bernd A1 - Frisch, Jérôme A1 - van Treeck, Christoph ED - Weidlich, Anke ED - Neumann, Dirk ED - Gust, Gunther ED - Staudt, Philipp ED - Schäfer, Mirko T1 - Time series aggregation for energy system design: review and extension of modelling seasonal storages T2 - Energy Informatics N2 - Using optimization to design a renewable energy system has become a computationally demanding task as the high temporal fluctuations of demand and supply arise within the considered time series. The aggregation of typical operation periods has become a popular method to reduce effort. These operation periods are modelled independently and cannot interact in most cases. Consequently, seasonal storage is not reproducible. This inability can lead to a significant error, especially for energy systems with a high share of fluctuating renewable energy. The previous paper, “Time series aggregation for energy system design: Modeling seasonal storage”, has developed a seasonal storage model to address this issue. Simultaneously, the paper “Optimal design of multi-energy systems with seasonal storage” has developed a different approach. This paper aims to review these models and extend the first model. The extension is a mathematical reformulation to decrease the number of variables and constraints. Furthermore, it aims to reduce the calculation time while achieving the same results. KW - Energy system KW - Renewable energy KW - Mixed integer linear programming (MILP) KW - Typical periods KW - Time-series aggregation Y1 - 2022 U6 - https://doi.org/10.1186/s42162-022-00208-5 SN - 2520-8942 N1 - 11th DACH+ Conference on Energy Informatics, 15-16 September 2022, Freiburg, Germany VL - 5 IS - 1, Article number: 17 PB - Springer Nature ER - TY - CHAP A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Schmitz, S. A1 - Sauerborn, Markus A1 - Rebholz, C. A1 - Iffland, D. A1 - Badstübner, R. A1 - Buck, R. A1 - Teufel, E. T1 - Test of a mini-mirror array for solar concentrating systems T2 - EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings ; 7th - 10th October 2008, Lisbon, Portugal : key lectures / ISES, International Solar Energy Society. Vol. 1 Y1 - 2008 SN - 978-1-61782-228-5 SP - 1242 EP - 1250 PB - Sociedade Portuguesa De Energia Solar (SPES) CY - Lissabon ER - TY - CHAP A1 - Herrmann, Ulf A1 - Kelly, Bruce A1 - Price, Henry ED - Steinfeld, Aldo T1 - Two Tank Molten Salt Storage for Parabolic Trough Solar Power Plants T2 - Proceedings of the 11th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies : September 4 - 6, 2002, Zurich, Switzerland / Paul Scherrer Institut, PSI; ETH, Eidgenössische Technische Hochschule Zürich Y1 - 2002 SN - 3-9521409-3-7 SP - 517 EP - 524 PB - Paul Scherrer Inst. CY - Villingen ER - TY - CHAP A1 - Neumann, Hannah A1 - Adam, Mario A1 - Backes, Klaus A1 - Börner, Martin A1 - Clees, Tanja A1 - Doetsch, Christian A1 - Glaeser, Susanne A1 - Herrmann, Ulf A1 - May, Johanna A1 - Rosenthal, Florian A1 - Sauer, Dirk Uwe A1 - Stadler, Ingo T1 - Development of open educational resources for renewable energy and the energy transition process T2 - ISES SWC 2021 N2 - The dissemination of knowledge about renewable energies is understood as a social task with the highest topicality. The transfer of teaching content on renewable energies into digital open educational resources offers the opportunity to significantly accelerate the implementation of the energy transition. Thus, in the here presented project six German universities create open educational resources for the energy transition. These materials are available to the public on the internet under a free license. So far there has been no publicly accessible, editable media that cover entire learning units about renewable energies extensively and in high technical quality. Thus, in this project, the content that remains up-to-date for a longer period is appropriately prepared in terms of media didactics. The materials enable lecturers to provide students with in-depth training about technologies for the energy transition. In a particular way, the created material is also suitable for making the general public knowledgeable about the energy transition with scientifically based material. KW - energy transition KW - renewable energies KW - open educational resources KW - dissemination KW - digitalization Y1 - 2021 U6 - https://doi.org/10.18086/swc.2021.47.03 N1 - ISES Solar World Congress, virtual conference 25-29 October 2021 PB - International Solar Energy Society CY - Freiburg ER - TY - CHAP A1 - Schwager, Christian A1 - Angele, Florian A1 - Schwarzbözl, Peter A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Model predictive assistance for operational decision making in molten salt receiver systems T2 - SolarPACES: Solar Power & Chemical Energy Systems N2 - Despite the challenges of pioneering molten salt towers (MST), it remains the leading technology in central receiver power plants today, thanks to cost effective storage integration and high cost reduction potential. The limited controllability in volatile solar conditions can cause significant losses, which are difficult to estimate without comprehensive modeling [1]. This paper presents a Methodology to generate predictions of the dynamic behavior of the receiver system as part of an operating assistance system (OAS). Based on this, it delivers proposals if and when to drain and refill the receiver during a cloudy period in order maximize the net yield and quantifies the amount of net electricity gained by this. After prior analysis with a detailed dynamic two-phase model of the entire receiver system, two different reduced modeling approaches where developed and implemented in the OAS. A tailored decision algorithm utilizes both models to deliver the desired predictions efficiently and with appropriate accuracy. KW - Power plants KW - Associated liquids KW - Decision theory KW - Electrochemistry Y1 - 2023 SN - 978-0-7354-4623-6 U6 - https://doi.org/10.1063/5.0151514 SN - 1551-7616 (online) SN - 0094-243X (print) N1 - SolarPACES: SOLAR POWER & CHEMICAL ENERGY SYSTEMS: 27th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27 September–1 October 2021, Online IS - 2815 / 1 PB - AIP conference proceedings / American Institute of Physics CY - Melville, NY 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 - https://doi.org/10.21105/joss.04406 SN - 2475-9066 VL - 7 IS - 76 SP - 1 EP - 4, 4406 ER - TY - CHAP A1 - Schwager, Christian A1 - Angele, Florian A1 - Nouri, Bijan A1 - Schwarzbözl, Peter A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Impact of DNI forecast quality on performance prediction for a commercial scale solar tower: Application of nowcasting DNI maps to dynamic solar tower simulation T2 - SolarPACES 2022 conference proceedings N2 - Concerning current efforts to improve operational efficiency and to lower overall costs of concentrating solar power (CSP) plants with prediction-based algorithms, this study investigates the quality and uncertainty of nowcasting data regarding the implications for process predictions. DNI (direct normal irradiation) maps from an all-sky imager-based nowcasting system are applied to a dynamic prediction model coupled with ray tracing. The results underline the need for high-resolution DNI maps in order to predict net yield and receiver outlet temperature realistically. Furthermore, based on a statistical uncertainty analysis, a correlation is developed, which allows for predicting the uncertainty of the net power prediction based on the corresponding DNI forecast uncertainty. However, the study reveals significant prediction errors and the demand for further improvement in the accuracy at which local shadings are forecasted. KW - Process prediction KW - DNI forecasting KW - Nowcasting KW - Uncertainty analysis KW - Molten salt receiver system, Y1 - 2024 U6 - https://doi.org/10.52825/solarpaces.v1i.675 SN - 2751-9899 (online) N1 - SolarPACES 2022, 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA IS - 1 PB - TIB Open Publishing CY - Hannover ER - TY - CHAP A1 - Schulte, Jonas A1 - Schwager, Christian A1 - Frantz, Cathy A1 - Schloms, Felix A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Control concept for a molten salt receiver in star design: Development, optimization and testing with cloud passage scenarios T2 - SolarPACES 2022 conference proceedings N2 - A promising approach to reduce the system costs of molten salt solar receivers is to enable the irradiation of the absorber tubes on both sides. The star design is an innovative receiver design, pursuing this approach. The unconventional design leads to new challenges in controlling the system. This paper presents a control concept for a molten salt receiver system in star design. The control parameters are optimized in a defined test cycle by minimizing a cost function. The control concept is tested in realistic cloud passage scenarios based on real weather data. During these tests, the control system showed no sign of unstable behavior, but to perform sufficiently in every scenario further research and development like integrating Model Predictive Controls (MPCs) need to be done. The presented concept is a starting point to do so. KW - Molten salt receiver KW - Star design KW - Control optimization KW - Cloud passages Y1 - 2023 U6 - https://doi.org/10.52825/solarpaces.v1i.693 SN - 2751-9899 (online) N1 - SolarPACES 2022, 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA IS - 1 PB - TIB Open Publishing CY - Hannover 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 - https://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 - Baumann, Torsten A1 - Teixeira Boura, Cristiano José A1 - Eckstein, Julian A1 - Felinks, Jan A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Schmitz, Stefan A1 - Zunft, Stefan T1 - Air-sand heat exchanger T2 - 6th International Renewable Energy Storage Conference (IRES 2011) : November 28 - 30, 2011, bcc Berlin Congress Center, Berlin, Germany / EUROSOLAR ... Y1 - 2011 PB - Eurosolar CY - Bonn ER -