Phase Change Materials for Heat Batteries


Sunamp has developed new heat-storage technology using Phase-Change Materials (PCMs).

Sunamp heat batteries store heat and release it on demand to provide space heating and hot water. The technology makes innovative use of PCMs that can store and release heat as they change phase – in much the same way as hand warmers. However, the company faced problems with the poor performance of commercially available PCMs. This reduced the ability of the batteries to store and release heat after multiple charge-discharge cycles.

Interface introduced Sunamp to Professor Colin Pulham and his team at the University of Edinburgh. The team worked with the company to develop additives that extend the battery’s lifetime. Sunamp now markets one of the world’s most efficient heat batteries. The development of these products has underpinned significant company growth. A trial in over 600 households has demonstrated a 20% reduction in the cost of heat.

Sunamp and The University of Edinburgh.


  • Access to expertise to support the development of a commercially viable product.
  • A strong and ongoing collaboration that has delivered substantial benefits to both partners, society, and the wider economy.
  • Exchange of highly trained research staff, including those taking permanent posts with Sunamp.


The partnership has accessed support and funding from Interface, the Energy Technology Partnership, UKRI, DECC, InnovateUK, Diamond Light Source, and the EPSRC Impact Acceleration Account.


 etp-logo  interface240