HP-BIG: Reduction of the heat price of large-scale solar thermal systems with heat pipe vacuum tube collectors

Bert Schiebler, Dipl.-Ing. (FH)
Tel.: +49 (0)5151-999 524
E-Mail: schiebler@isfh.de

Schematic drawing of the heat pipes cross section in the operating range and in stagnation periods as well as several collector rows of a large-scale solar thermal system for assisting a heat network or a industrial process.

Large-scale solar thermal plants for assisting heating networks as well as commercial and industrial applications can make a significant contribution to the decarbonisation of the heating sector and become increasingly important. The main goal of the project is therefore to increase the attractiveness of such systems and to significantly reduce the price of heat compared to the state of the art. In order to achieve this cost reduction, systems with heat pipe-based (HP) evacuated tube collectors are being further developed in the project. Due to their simple hydraulics and inherent ability to selectively limit system temperatures, these collectors offer an untapped potential for use in the targeted application areas, especially in process heat generation and in the support of district heating networks with high solar fractions. The basis for the further development is the MEGA collector from AKOTEC as well as the results achieved by the partners from previous research activities with HP collectors.

The project is structured in three main phases: In the 1st phase, feasibility studies as well as data on large-scale plants are researched and representative installations are investigated by measurement in order to define technical and non-technical requirements for the development of the large-scale plants in a concrete and practical way. In the 2nd phase, different approaches will be investigated, initially based on adapting the manufacturing processes for using new material combinations. Both cost-effective and at the same time high performance vacuum tubes are being developed. Furthermore, reflectors attached to the back should increase the solar yield. This will be investigated simulatively using optical models and later verified by measurements on suitable prototypes. In the 3rd phase a demonstration plant (Live-Lab) is to be built and fully investigated over a long time for the evaluation of the new developments under real environmental and operating conditions. Finally, an energetic, economic and ecological evaluation will be carried out, whereby overall a significant reduction in the heat price is expected for large-scale solar thermal plants.


AKOTEC Produktionsgesellschaft mbH, Grundmühlenweg 3, 16278 Angermünde, Germany

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NARVA Lichtquellen GmbH + Co. KG, Erzstraße 22, 09618 Brand-Erbisdorf, Germany



01.11.2021 – 31.10.2024


The project “Reduction of the heat price of large-scale solar thermal systems with heat pipe vacuum tube collectors” underlying this publication is funded by the German Federal Ministry for Economic Affairs and Climate Action (reference number 03EN6011A-C) based on a decision of the German Parliament. The authors alone are responsible for the content of this publication.

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