Innovation provider



Ulf Andersson
Phone: +46 8 965773


Phase Change Materials
A material undergoing a phase change, like melting and evaporating, take up a lot of heat which later can be recovered at the particular phase change temperature. Storing thermal energy (heat or cold) using such phase change processes is called PCM technology (Phase ChangeMaterials). Here, utilizing the melting/freezing is often more practical as compared to the evaporation/condensation since the volume change associated with the change of phase is large during evaporation and thus creates some practical problems.
A well-known example of PCM-technology is utilizing ice for storing cold — approximately 90 kWh cold per cubic meter of ice. This is the same amount of energy that would be stored in liquid water when utilizing a temperature change from say 0 ºC to 80 ºC. Other materials, like salt blends, paraffin and sugar alcohols provide PCM storage at other temperatures — the application decides which material is best.
Thermal Energy Storage using PCM Technology
Storage of thermal energy should be a natural part of any energy system. One reason for this is that it enables the use of sources like solar energy and free-cooling. Another reason is that short term (hourly/daily) storage provides an effective solution for managing peak power demand such that the utilization of equipment and distribution networks (e.g., district energy lines) is optimized.
With PCM technology, a large amount of thermal energy can be stored close to the melting/freezing temperature of the PCM. In heating applications, about 100 kWh/m3 can be stored, that is twice the amount in most conventional hot water storage concepts. For cooling applications 4-5 times the amount of cold stored in a chilled water storage is possible when using PCM technology.


Ecostorage Sweden AB has three primary products and services: thermal energy transportation, free-cooling of buildings, and a compact (solar) hot water heater. In addition to these areas, more conventional consultancy type projects are accepted, and we also conduct R&D funded by e.g. the Swedish Energy Agency, the Swedish District Heating Association and EU.

Innovative aspects (ecologic, social and economic)

Application examples

Below, some of our present projects are described.

Transport of Surplus Heat from SSAB Oxelösund Steel Works

In this project the transportation of thermal energy using advanced storage technologies, like PCM, is further examined. Here, the focus is on the providing knowledge on the characteristics of potential receiving heat by way of truck, train and boat. Several cases are examined like a district energy heating plant receiving industrial waste heat, or a small municipality receiving heat from a larger utility combined heat and power plant. This project is financed by the Swedish District Heating Association and the Energy Agency via the R&D program Fjärrsyn.

Transport of Industrial Surplus Heat — Fjärrsyn

This project is a collaborative effort between Ecostorage Sweden AB, SSAB Oxelösund, and Climatewell AB. The aim is to develop systems for effective transportation of thermal energy over distances, and between places where district heating is not cost-effective. When utilizing advanced thermal energy storage technology and transporting energy by way of truck, train, or boat, there is a large potential to increase the use of industrial surplus heat for heating and cooling in the built environment. Today, industries are often too far away from large heating and cooling demands which means that several TWh/year of good quality surplus heat remains unused and is wasted. The project is co-financed by the industrial partners and the Swedish Energy Agency.

COST Action on Phase Change Materials for the Built Environment

Matching energy supply with to the energy demand can be overcome by the incorporation of proper energy storage systems. PCMs are interesting because of the large amount of heat absorbed at a constant temperature. Ecostorage Sweden AB participate in a European Cooperation in the field of Scientific and Technical Research — COST— with the aim of accelerating the long-term development of PCM storage systems by way of characterization and simulation of the next generation modified hybrid PCMs.



Current stage of development

Development phase – laboratory tested

Intellectual Property Rights

Patent granted

Country of origin


Country of application



National Contact Point

Uwe Fortkamp
IVL Svenska Miljöinstitutet AB
Valhallavägen 81
P.O. Box 210 60
114 27 Stockholm

Tel: +46 8 598 56300
Tel: +46 8 598 56390