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  - https://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  - 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
N2  - The cost of solar tower power plants is dominated by the heliostat field making up roughly 50% of investment costs. Classical heliostat design is dominated by mirrors brought into position by steel structures and drives that guarantee high accuracies under wind loads and thermal stress situations. A large fraction of costs is caused by the stiffness requirements of the steel structure, typically resulting in ~ 20 kg/m² steel per mirror area. The typical cost figure of heliostats (figure mentioned by Solucar at Solar Paces Conference, Seville, 2006) is currently in the area of 150 €/m² caused by the increasing price of the necessary raw materials. An interesting option to reduce costs lies in a heliostat design where all moving parts are protected from wind loads. In this way, drives and mechanical layout may be kept less robust, thereby reducing material input and costs. In order to keep the heliostat at an appropriate size, small mirrors (around 10x10 cm²) have to be used, which are placed in a box with a transparent cover. Innovative drive systems are developed in order to obtain a cost-effective design. A 0,5x0,5 m² demonstration unit will be constructed. Tests of the unit are carried out with a high-precision artificial sun unit that imitates the sun’s path with an accuracy of less than 0.5 mrad and creates a beam of parallel light with a divergence of less than 4 mrad.
Y1  - 2010
U6  - https://doi.org/10.1115/1.4000332
SN  - 0199-6231
SN  - 1528-8986 (eISSN)
VL  - 132
IS  - 1
PB  - ASME
CY  - New York
ER  - 
TY  - CHAP
A1  - Baumann, Torsten
A1  - Teixeira Boura, Cristiano José
A1  - Göttsche, Joachim
A1  - Hoffschmidt, Bernhard
A1  - O'Connell, Bryan
A1  - Schmitz, Stefan
A1  - Zunft, Stefan
T1  - Air/Sand heat exchanger design and materials for solar thermal power plant applications
T2  - SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France
Y1  - 2010
SP  - 146
EP  - 147
PB  - Soc. OSC
CY  - Saint Maur
ER  - 
TY  - JOUR
A1  - Hennecke, Klaus
A1  - Schwarzbözl, Peter
A1  - Hoffschmidt, Bernhard
A1  - Göttsche, Joachim
A1  - Koll, Gerrit
A1  - Beuter, Matthias
A1  - Hartz, Thomas
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  - CHAP
A1  - Hirsch, Tobias
A1  - Abel, Dirk
A1  - Bohn, Dieter E.
A1  - Diehl, Moritz
A1  - Hoffschmidt, Bernhard
A1  - Pitz-Paal, Robert
T1  - The Virtual Institute for Central Receiver Power Plants - vICERP
T2  - SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings
Y1  - 2009
SN  - 9783000287558
PB  - Deutsches Zentrum f. Luft- u. Raumfahrt
CY  - Stuttgart
ER  -