Task 39
Task 39
SHC Task 39

Polymeric Materials for Solar Thermal Applications


The objectives shall be achieved in the following Subtasks:

Subtask A:      Information         (Norway, Michaela Meir)
Subtask B:      Collectors           (Germany, Stephan Fischer)
Subtask C:      Materials             (Austria, Gernot Wallner)

The Task started at October 1, 2010 and will be terminated at September 30, 2011.


Subtask A: Information


The objective of Subtask A is to collect, create and disseminate information about the application of polymeric materials in solar thermal systems and their figures or merits, especially in terms of cost/performance ratios for an acceptable lifetime, in order to increase the penetration of good applications into the market.

The production of a yearly newsletter, targeted at the solar- and polymer industry, a coloured flyer for promotion of the present Task and the preparation of an electronic or printed handbook on polymeric materials in solar thermal applications are main results of this Subtask.


  • Updating of the state-of-the-art overview of existing applications of polymeric materials in solar thermal systems and other relevant industry sectors.
  • Performance of two case studies, where a total cost accounting approach is adopted, for assessment of suitability of using polymeric materials in solar thermal applications.
  • Investigation of standards, regulations and guidelines with regard to the applications of polymeric materials in solar thermal systems and building integration.
  • Extension of  the database consisting of showcases where solar collectors using mostly polymeric materials have been successfully integrated into the architecture.
  • Dissemination of information of the work and results in all Subtasks to a wide audience.

These activities will be carried out within five different projects:

Project A1:  State of the art: Polymeric materials in solar thermal applications
Project A2:  Taskforce on Total cost accounting approach
Project A3:  Taskforce on Standards, regulations and guidelines
Project A4:  Database of successful architectural integration
Project A5:  Dissemination of information

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Subtask B: Collectors


Based on the results of the first phase of this subtask, the objectives for the extension phase are focused on the development of:

  • new collectors, made completely or partly with polymeric materials, with a profitable cost of ownerships,
  • innovative concepts based on polymeric materials (integrated collector storage, thermo-syphon systems) or adapted to specific requirements of polymeric collectors (overheating protection, pressure)
  • other components of a solar thermal system (piping, fitting, storage, drain back vessel) that could benefit of polymeric materials or processes.


Based on the updated state of the art from Subtask A, studies and development of new collectors, systems and components will be produced in order to show the feasibility, performance, durability and cost savings.

To achieve the objectives, the activities will be carried out within 3 different projects:

B1: Collector
B2: System
B3: Others components

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Subtask C: Materials

As shown in Phase I of IEA SHC Task 39 polymer engineering and science offer great potential for new products in solar thermal systems, which simultaneously fulfil technological and environmental objectives as well as social needs. The major achievements within Phase I of Task 39 concerned the significant improvement in the long-term stability of an extruded polymer collector as well as the realization of a polypropylene based modular storage tank. Furthermore, a variety of novel polymeric material grades and components for solar-thermal systems (e.g., spectrally selective coatings with improved performance and commercial availability, injection-molded installation board, extruded spacers for the fixing of an absorber in the collector frame, thermoformed casings for collectors based on polycarbonate blends, polymeric foams with enhanced service temperature) were realized.

The final product performance, functionality, durability and costs not only depend on the type of the polymeric material used, but also on many other factors related to product design, processing and production. As evidenced in Phase I of Task 39 the different components in solar thermal systems have to fulfill a complex material property profile which can be provided only by multi-functional polymer compounds. The classical differentiation between structural (load-carrying) and functional polymeric materials is therefore not suitable in context with the application of plastics in solar thermal systems.

For the extension of Task 39 (Phase II) the following main objectives of Subtask C are defined:

  • Further development and investigation of multi-functional polymeric materials for various components in solar thermal systems considering different plant types and climate zones.
  • Evaluation of polymer processing methods for the production of specimen and components with special focus up to the sub-component level (e.g., multi-layer films and sheets). Full components will be developed in Subtask B.
  • Development of testing and characterization methods and modeling tools for the application-oriented assessment of the performance and durability.

Activities within this Subtask include:

  • Formulation of multi-functional polymeric materials for various components of solar thermal systems (e.g., absorber, insulation and frame of a collector, storage tank components). The considered polymeric material classes will include thermoplastics (i.e., melt processable materials), elastomers (i.e., chemically cross-linked soft materials) and thermosets (i.e., chemically cross-linked stiff materials).
  • Compounding of polymeric materials considering a variety of functional fillers and additives allowing for improved processability and enhanced performance.
  • Production of specimen and sub-components by applying various mass production processing technologies (e.g., injection moulding, compression moulding, extrusion, coating technologies, lamination and joining technologies).
  • Establishment of a tool box for the quality testing of polymeric materials for specific applications in ST systems considering the various material states along the value creation chain.
  • Implementation and application of analytical and technical methods for the characterization of properties, long-term behaviour and relevant aging and degradation phenomena.
  • Establishment of micro-structure/property/processing/performance relationships.

Subtask C requires input from Subtasks A and B in terms of components to be developed and requirements to be fulfilled. Vice versa input to Subtasks A and B will be given to the specific properties and processing routes of plastics which are due to the macromolecular structure of polymers very different to inorganic materials, such as metal, ceramic or glass (e.g., time/temperature dependent behaviour; functional properties; plastics processing).

According to the objectives the work will be carried out in the following three projects:

C1: Multi-Functional Polymeric Materials
C2: Processing and Evaluation of Components
C3: Methods for Testing and Characterization of Polymeric Materials