We present the HelioPoint method - a fast airborne method for calibrating entire heliostat fields

Algner, Niels

Broda, Rafal

Happich, Christoph

Krauth, Julian

Kämpgen, Andreas

Röger, Marc

Schnerring, Alexander

Ulmer, Steffen

Institute of Transport Research:Publications

Julian Krauth26th Cologne Solar ColloquiumJune 22, 2023FAST CALIBRATION OF HELIOSTATSMotivation2▪ High number of heliostats ▪ High pointing accuracy required▪ Faster calibration ➜ shorter commissioning time!Julian Krauth, DLR, June 22, 2023AshalimPlot B by MegalimSolar PowerAshalim121 MWe~50.000 heliostatsMany different methods3Julian Krauth, DLR, June 22, 2023Sattler et al. – Solar Energy 207, 110 (2020)Many different methods4Julian Krauth, DLR, June 22, 2023Sattler et al. – Solar Energy 207, 110 (2020)Solar tower CESA1 from CIEMATHeliostat field CESA1 from CIEMATAlternative technique from NREL5Julian Krauth, DLR, June 22, 2023Mitchell and Zhu, Solar Energy 209, 431 (2020)Guangdong Zhu, NREL6METHOD & DATA ACQUISITIONJulian Krauth, DLR, June 22, 2023The measurement principle (HelioPoint method)▪ LED and camera fitted to a drone▪ Normal vector is bisector of LED and camera7Julian Krauth, DLR, June 22, 2023The setup▪ Commercially available drone equipped with ▪ RTK▪ calibrated camera▪ strong LED8Julian Krauth, DLR, June 22, 2023                                             Tested at the solar tower in Jülich9Julian Krauth, DLR, June 22, 2023Solar tower Jülich, DLRIlluminated surfaceField of viewThe Image Data10Julian Krauth, DLR, June 22, 2023                                Flight Route PlanningSteps:1. Definition parameter set11Julian Krauth, DLR, June 22, 2023Calibration points by time and date                                                                                                                                  Flight Route PlanningSteps:1. Definition parameter set2. Building clusters of heliostats 12Julian Krauth, DLR, June 22, 2023Divide field into subgroupsFlight Route PlanningSteps:1. Definition parameter set2. Building clusters of heliostats 3. Creating the flight pattern13Julian Krauth, DLR, June 22, 2023                                Flight pattern to find surface normals                                heliostatUncertainty margin                                Flight Route PlanningSteps:1. Definition parameter set2. Building clusters of heliostats 3. Creating the flight pattern4. Deriving flight routes➔ Applicable to industry-sized heliostat fields➔ Effort for 50 MW reference-scenario is feasible14Julian Krauth, DLR, June 22, 20233 flights for one calibration pointof entire heliostat field15DATA ANALYSIS & RESULTSJulian Krauth, DLR, June 22, 2023Image analysis 16Julian Krauth, DLR, June 22, 2023Image analysis 17Julian Krauth, DLR, June 22, 2023Merge different imagesExemplary sampling distribution for one heliostat                                      from one imageExtract heliostat normal vectors▪ Calculate normal vectors using drone position and heliostat position18Julian Krauth, DLR, June 22, 2023Heliostat surface with local normal vectorsAveragefor each heliostat                                                                    Measured heliostat orientationsResults and ConclusionDLR and CSP Services have developed a fast method for heliostat calibration▪ Projected calibration time of a few weeks for a common 50 MW plant▪ No further infrastructure required (but the heliostats)▪ Arbitrary calibration points can be measured at any time▪ Validation tests conducted in early 2023:▪ 5 heliostats were measured with HelioPoint method and compared against precise data obtained with local QDec-H system ▪ Average deviation was <0.5 mrad (with 0.2 mrad STD).▪ Industrial application readiness within common research project HelioPoint-II until end of 202319Julian Krauth, DLR, June 22, 2023Outlook▪ Development and optimization is ongoing20Julian Krauth, DLR, June 22, 2023Treatment of overlapping LED reflections Detect reflections using Deep LearningMeasure heliostats during trackingFully automated flight system (push a button)Calculate slope deviation mapsImprintTopic: Fast calibration of HeliostatsDevelopment of a fast airborne method for efficient and accurate calibration of entire fields of heliostats. Date: 2023-06-22Author: Julian J. Krauth, Christoph Happich, Niels Algner, Rafal Broda, Andreas Kämpgen, Alexander Schnerring, Steffen Ulmer, and Marc RögerInstitute: Institute of Solar Research, DLR, in collab. with CSP ServicesImage credits: All i ages “DLR (CC B -NC-ND    )” or fro  CSP Services GmbH unless otherwise statedThe presentation has been designed using icons from Flaticon.comAcknowledgements: Felix Göhring (DLR), Oliver Kaufhold (DLR), BMWK21Julian Krauth, DLR, June 22, 2023

Fast calibration of heliostats

https://elib.dlr.de/199127/1/KRAUTH_fast_calibration_of_heliostats.pdf

Fast calibration of heliostats

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