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 - 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 - 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 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 - Hove, T. T1 - Mapping global, diffuse and beam solar radiation over Zimbabwe / T. Hove ; J. Göttsche JF - Renewable energy. 18 (1999), H. 4 Y1 - 1999 SN - 1879-0682 SP - 535 EP - 556 ER - TY - JOUR A1 - Göttsche, Joachim A1 - Gabrysch, K. A1 - Delahaye, A. A1 - Schwarzer, Klemens T1 - Solar-Campus Juelich - Energy performance and indoor climate JF - AIVC 23rd conference - EPIC 2002 AIVC (in conjunction with 3rd European Conference on Energy Performance and Indoor Climate in Buildings) - 23-26 October 2002 - Lyon - France - vol 2 Y1 - 2002 SP - 381 EP - 386 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 - Hennecke, Klaus A1 - Schwarzbözl, Peter A1 - Hoffschmidt, Bernhard A1 - Göttsche, Joachim A1 - Koll, G. A1 - Beuter, M. A1 - Hartz, T. T1 - The solar power tower Jülich – a solar thermal power plant for test and demonstration of air receiver JF - 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 Y1 - 2007 SN - 978-7-302-16146-2 N1 - Solar World Congress <2007, Beijing> ; International Solar Energy Society SP - 1749 EP - 1753 PB - Tsinghua Univ. Press CY - Beijing 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 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Schmitz, Stefan A1 - Sauerborn, Markus T1 - Solar Concentrating Systems Using Small Mirror Arrays / Göttsche, Joachim ; Hoffschmidt, Bernhard ; Schmitz, Stefan ; Sauerborn, Markus ; Buck, Reiner ; Teufel, Edgar ; Badstübner, Karin ; Ifland, David ; Rebholz, Christian JF - 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 Y1 - 2009 SN - 9780791843208 N1 - International Conference on Energy Sustainability ; (2 : ; 2008.08.10-14 : ; Jacksonville, Fla.) ; ES ; (2 : ; 2008.08.10-14 : ; Jacksonville, Fla.) SP - 1 EP - 5 PB - ASME CY - New York, NY 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 A1 - Hoffschmidt, Bernhard A1 - Schmitz, Stefan A1 - Sauerborn, Markus T1 - Solar Concentrating Systems Using Small Mirror Arrays JF - Journal of solar energy engineering Y1 - 2010 SN - 0199-6231 VL - Vol. 132 IS - Iss. 1 SP - 4 S. ER - TY - JOUR A1 - Göttsche, Joachim A1 - Alexopoulos, Spiros A1 - Dümmler, Andreas A1 - Maddineni, S. K. T1 - Multi-Mirror Array Calculations With Optical Error N2 - 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. KW - solar process heat KW - concentrating collector KW - raytracing KW - point-focussing system Y1 - 2019 SP - 1 EP - 6 ER - TY - JOUR A1 - Sattler, Johannes, Christoph A1 - Röger, Marc A1 - Schwarzbözl, Peter A1 - Buck, Reiner A1 - Macke, Ansgar A1 - Raeder, Christian A1 - Göttsche, Joachim T1 - Review of heliostat calibration and tracking control methods JF - Solar Energy N2 - 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. Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.solener.2020.06.030 VL - 207 SP - 110 EP - 132 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Blanke, Tobias A1 - Hagenkamp, Markus A1 - Döring, Bernd A1 - Göttsche, Joachim A1 - Reger, Vitali A1 - Kuhnhenne, Markus T1 - Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates JF - Geothermal Energy N2 - Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellström’s borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54% of the outer pipe radius for laminar fow and 60% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth’s thermal properties and the fow type. Conclusively, coaxial geothermal probes’ design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics. Y1 - 2021 U6 - http://dx.doi.org/10.1186/s40517-021-00201-3 SN - 2195-9706 N1 - Corresponding author: Tobias Blanke VL - 9 IS - Article number: 19 PB - Springer CY - Berlin ER -