Jumbotrough – Development of a Robust Large-Format Parabolic Trough Reflector

Duration: 12/2019 - 05/2022
Contracting Authority/ Sponsors:
Bundesministerium für Wirtschaft und Energie (BMWi)
Project Partners: Fraunhofer-Institut für Solare Energiesysteme ISE; Fraunhofer-Institut für Werkstoffmechanik IWM; TS ELINO GmbH; HEGLA GmbH & Co. KG; Von Ardenne GmbH
Project Focus:
Presentation of the JUMBOTROUGH solution (right) in comparison to the state of the art production (left)
© Fraunhofer IWM
Presentation of the JUMBOTROUGH solution (right) in comparison to the state of the art production (left).

The project objective is to develop a new manufacturing process for large-format laminated glass mirrors. The feasibility shall be demonstrated by producing prototype parabolic trough mirrors. A prototype measuring 1.5m x 3m will be developed, representing all essential requirements for the final product. The functionality of a full format mirror can thus be proven.

The Jumbotrough project pursues a novel mirror concept in which the mirror is constructed from a precisely bent carrier glass using an innovative bending process. A thin flat glass coated with a mirror layer using PVD is cold-bent by laminating it onto this curved carrier glass.

The parabolic trough mirror to be developed in Jumbotrough reflector will have a higher reflectivity compared to commercial parabolic trough mirrors. On the one hand, the novel glass bending process shall improve shape accuracy, and on the other hand, the PVD coating shall increase solar reflection by up to 1% due to the lower absorption in the glass. At the same time, the mirror has a high mechanical and long-term stability due to the thick, curved glass substrate.

Upon development of the mirror, a made-to-measure jumbo parabolic trough collector on the innovative mirror is to be developed in a follow-up project.

The innovative approach for a highly reflective parabolic trough mirror is possible due to the development of an industrial manufacturing process consisting of an industrial glass bending furnace, a PVD sputtering system, lamination, and glass handling machines.


Digitalization and integration of the value chain are considered in the development of production processes and quality control. The research work is carried out with modern and computer-assisted methods and is based on procedures with digital data processing based on Industry 4.0. Sensors and actuators in the equipment provide data that is processed digitally. The acquired data are used for the intelligent control, documentation and transfer of process and material histories along the value chain, inline quality control, and structural and process optimization by simulation and machine learning methods.

The manufacturing processes can be scaled and commercialized following the project. This puts German companies in the position to remain leaders in CSP technology and provides them with the opportunity to sell the newly developed plant technology to CSP companies worldwide.