Deutsche Version  ACT
Thermal Storage
Latent heat storage with super insulation 1.8.2016

Example for pipes
© Solvis/Hochschule Mannheim

How to store heat for weeks

Scientists are developed solar cylinders, which can store solar heat for

weeks. For this purpose they combineed a patented latent heat storage

material with super insulation. Compared to equally sized conventional

water storages, the solar cylinders have three times the storage

capacity and have only one tenth of the heat losses.

Project status Project completed
Type of storage Latent heat storage (salt)
Temperature type low temperature
Storage/Charging direct
Storage time short (hours to days)
Number of cycles 3.000
Charging temperature 35 up to 95 °C
Discharging temperature 35 up to 95 °C
Storage capacity 140.000 kJ
Energy storage density 300 MJ/m³
Project duration January 2013 until June 2016

As PCM a patented low cost eutektikum will be used. The necessary increased heat distribution will be achieved with included elements such as new developped plastic shielded graphite elements to evoid inflences by damages elements. The heat losses will be reduced by an active vakuum system. Infrared radiation will be reduced by middle infrared reflectors. The new concept should be mountable as an after sales service.

  • Half mould at Solvis Max © Solvis/Hochschule Mannheim
  • Security vessel PCM © Solvis/Hochschule Mannheim
  • Bolster with PCM © Solvis/Hochschule Mannheim
  • Whole storage © Solvis/Hochschule Mannheim
  • Melting behaviour © Solvis/Hochschule Mannheim
  • Design testing module © Solvis/Hochschule Mannheim
  • Example for pipes © Solvis/Hochschule Mannheim

The practicable use of PCM can - due to own developments - be successfully realized by including heat transfer lines integrated in the tank design. The additional Volume at the outside of the tank can increase the capacity by a factor 4. Additional elements can be in the inner part of the tank. The later on marketing is done by Solvis in combination with the well-established product line Solvis Max. The used new PCM-Material is tested in a >3000 cycles test. The price is below 500€/to, which is  20 times cheaper than paraffin used in similar applications. The costs for a later product a expected that a 10 000 tank market per year can be achieved.


  • Realization of a simulation model for heat flux in the PCM
  • Calculation model for vacuum isolator
  • Laboratory stands for testing compound materials
  • Producing half tubes for installation at Solvis tanks
  • Basic development superinsulation
  • Development vacuum sensor
  • Development PCM-VIP-combination module
Supported by: The Federal Government on the basis of a decision by the German Bundestag


no news in this list.


Research funding

The information system EnArgus provides information on research funding, including on this project (German only).