Hochschule Karlsruhe Hochschule Karlsruhe - University of Applied Sciences
Hochschule Karlsruhe Hochschule Karlsruhe - University of Applied Sciences

Institute for Digital Materials Research

BMWi: AIF - Textile-based collector with integrated latent heat storage for solar thermal energy use (Textile Solar Thermal)

Contact: Prof. Dr. rer. nat. Britta Nestler
Funding: Federal Ministry for Economic Affairs and Energy (BMWi)
Start date: 2015
End date: 2017

Within the framework of the proposed research project, a textile collector is to be developed using hybrid technology, i.e. the solar collector and heat storage medium are housed in one unit: the absorber layer made of a black spacer textile is designed so that air can flow through it. The storage medium for the thermal energy is located below or at the end of the collector. Due to the high storage density, a latent heat storage medium is provided, which consists of knitted monofilaments and thus offers enormous advantages in terms of fast and efficient heat exchange. The storage medium can thus be directly charged with solar energy.

At the same time, air can flow through and is also heated by the sun. When the stored thermal energy is called up, air also flows through the system, but the heating of the air is not realised by the solar radiation but by the heat accumulator. The layers for the thermal insulation and air conduction are to be cleverly arranged and dimensioned by means of advance calculations in order to avoid overheating of a possible underlying building wall and to keep the heat losses to a minimum in the case of heating.
The textile collector to be developed should have the following features:

  • a flexible material composition for the production of a textile collector composite,
  • an integrated heat accumulator as a day-night accumulator,
  • industrial production of the composite and the collector systems,
  • easy integration into buildings, for example on façades and roofs,
  • added value in use,
  • good economic efficiency.

Another goal of the project is the integration of the hybrid solar collector system into the heat management concept of buildings.