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Phase Change Materials boosts buildings' energy storage potential

(Photo copyright RMJM and ENU) (Photo copyright SARL
Busipolis de Metz)

Eco innovation sits at the centre of the EU’s quest for a resource-efficient Europe and an excellent example of LIFE’s role in bringing new environmental technologies to the market can be shown by a Luxembourg LIFE project that developed a novel passive energy saving panel for use in new and renovated buildings.

Eco innovators at Luxembourg’s base of the private sector company DuPont have joined forces with ecologically-minded business partners in Europe’s SME sector to invent a new energy saving technology. The technology targets a growing concern about the environmental legacy of prefabricated building techniques. These use lightweight modular materials like metal or wood and are increasingly common, especially in the housing market, because they can be built faster and cheaper than construction methods using conventional concrete or stone materials. Such prefabricated systems may exhibit lower construction costs but they often remain resource-inefficient due to their limited ‘thermal mass’.

Thermal mass is the ability of a building to absorb and store heat. Buildings that contain a lot of dense material, like concrete or stone, are able to soak up heat or sun radiation and store this within the walls, floors and ceilings. Buildings made of materials like wood and metal cannot soak up and store as much energy and have a lower thermal mass. Rooms in low thermal mass buildings therefore heat up quicker during hot weather and become colder faster in winter. They are less energy efficient because they have to consume new energy each time the room needs to be heated to a comfortable temperature, or cooled down using air conditioning units. Heating and air conditioning appliances are the largest users of energy in Europe’s buildings.

Buildings with higher thermal mass are able to better absorb heat energy from solar or indoor sources. They store the heat and release it when the room temperature drops, as part of a natural passive energy cycle. These types of buildings provide more stable internal temperatures and they tend to have lower heating or cooling costs. Market trends for lightweight buildings with low thermal mass have hence created an escalating environmental problem that conflicts with practical and policy requirements for increased energy efficiency and improved energy balances.  

Phase Change Material

(Photo copyright RMJM and ENU) (Photo copyright RMJM and ENU)

LIFE’s EFFERNERGY project has created an eco-innovation solution for this problem by designing a new type of lightweight building material that exhibits a high thermal mass. A special type of Phase Change Material’ (PCM) has been integrated within a standard plaster-board type structure and this PCM provides the high thermal mass. The thin and user-friendly PCM panels works like a natural energy storage system and can be easily fitted to the walls, floors or ceiling of a building. Panels contain a suspended wax that starts to soak up solar energy during the day once a room temperature rises above 21 degrees centigrade. The melting wax is held in position in the high-tech panel and this ‘phase change’ process provides a simple but effective passive solution for reducing energy demands from air-conditioning.

After the sun goes down and the room temperature starts to cool below 21 degrees centigrade, the panels’ suspended wax begins to solidify again and in doing so it releases its latent heat energy back into the room. This opposite part of the panels’ phase change process can help to reduce heating energy costs.


EFFERNERGY received a LIFE grant of €1.51 million to co-finance the work involved in developing its Energain® Panel. Much of the money was used by the SMEs partners during the project’s three year term (2005-2008) to determine the panels’ optimal performance parameters. EFFERNERGY continues to build on its initial LIFE-funded project and plans are underway for a new higher performance Energain® Panel that will be even more commercially competitive.

LIFE’s support for this eco-innovation has shown that energy storage is a core part of energy efficiency, and that PCM is an excellent solution for energy storage in modern building methodologies. EFFERNERGY’s successful resource efficiency results helped it to win the award as one of this year’s Best LIFE Environment projects, and more information about the Energain® Panel is available from the project website. A selection of case studies is also hosted on the website which show how panels are being used commercially in different energy saving situations.

For yet more examples of projects funded by the programme, visit the LIFE project database.

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