When a material melts or freezes, a certain amount of energy is absorbed or released at a nearly constant temperature. Melting 1 kg of ice, for instance, sets free as much energy (heating) as is needed to heat the same amount of water with 80°C (cooling). This latent heat of a material's phase change can be employed to store and release heat when needed. In this case we f.e. apply excess heat from solar collectors during the day to freeze a certain compact material. When the heat is required at night, we allow the material to melt and to let go of its energy, in the form of heat. Since different materials have different chemical and physical properties, Phase Change Materials (PCM) technology can address many different heating and cooling requirements.


Phase Change Materials:

  • release thermal heat at a nearly constant temperature near the specific material’s phase change temperature.
  • have a high energy storage density within a limited operational temperature range, compared to traditional water buffers. This makes PCMs a compact storage option that can reduce the buffer volume by a factor 2 to 3.
  • allows for the efficient storage and optimal usage of thermal energy from intermittent (renewable) sources on a daily time scale.
  • reduce energy losses. They are very suitable for daily usage as well as on longer time scales.
  • can deliver high peak power outputs.
  • are commercially available in a large variety, giving access to a vast range of phase transition temperatures with applications for both heating and cooling purposes (s.a. floor heating or domestic hot water)
  • offer different size scale possibilities, ranging from compact solutions to very large storage units.

EnergyVille offers fully-equipped test facilities, up to temperatures of 90 °C (domestic and tertiary applications) and an experienced team of experts.

Phase Changing Materials


micro-CHP systemenThe daily mismatch between heat demand on a domestic level and supply from renewable sources (such as solar collectors, PV coupled heat pumps and heat from micro-CHP units) implies the need for efficient and compact storage methods of thermal energy. PCMs offer a compact solution, as compared to the more conventional water storage tanks that store perceptible heat.

PCM heating & cooling can be applied for all storage purposes, but its compact size offers advantages especially to integrated and/or transportable energy storage.


  • Manufacturers of thermal energy buffers and solar boilers aiming at the incorporation of PCMs in their energy systems.
  • Producers of heat pumps considering compact storage units for heating and/or cooling purposes.
  • Mobile & transportable storage units, like truck-mounted containers.