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  - Rau, Christoph
A1  - Alexopoulos, Spiros
A1  - Breitbach, Gerd
A1  - Hoffschmidt, Bernhard
A1  - Latzke, Markus
A1  - Sattler, Johannes, Christoph
T1  - Transient simulation of a solar-hybrid tower power plant with open volumetric receiver at the location Barstow
JF  - Energy procedia : proceedings of the SolarPACES 2013 International Conference
N2  - In this work the transient simulations of four hybrid solar tower power plant concepts with open-volumetric receiver technology for a location in Barstow-Daggett, USA, are presented. The open-volumetric receiver uses ambient air as heat transfer fluid and the hybridization is realized with a gas turbine. The Rankine cycle is heated by solar-heated air and/or by the gas turbine's flue gases. The plant can be operated in solar-only, hybrid parallel or combined cycle-only mode as well as in any intermediate load levels where the solar portion can vary between 0 to 100%.

The simulated plant is based on the configuration of a solar-hybrid power tower project, which is in planning for a site in Northern Algeria. The meteorological data for Barstow-Daggett was taken from the software meteonorm. The solar power tower simulation tool has been developed in the simulation environment MATLAB/Simulink and is validated.
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.egypro.2014.03.157
SN  - 1876-6102
VL  - 49
SP  - 1481
EP  - 1490
PB  - Elsevier
CY  - Amsterdam
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  -