Task 42, a joint Task with the IEA Energy Conservation through Energy Storage (ECES) Programme Task 24, was approved at the June 2008 IEA SHC Executive Committee Meeting in Graz, Austria.

From January 2009 to December 2012, Wim van Helden, SHC (ECN Energy Research Centre of the Netherlands) and Andreas Hauer, ECES (ZAE Bavarian Center for Applied Energy Research, Germany) will be the operating agents in charge of finding a way to bring the ongoing work on materials and applications together. This follows the conclusions of several IEA Annexes that materials are the main bottleneck for finding effective solutions for compact thermal energy storage, and that there is a need for new storage materials with a higher specific energy storage density and lower material cost. The point being that, although there are several groups around the world working on either thermal energy storage materials or applications, these activities are not sufficiently linked.

Particularly for solar thermal systems, thermal energy storage is essential. To reach high solar fractions, it is necessary to store heat (or cold) efficiently for longer periods of time. Until now, no cost-effective compact storage technologies are available to do this. For high solar fraction systems, hot water stores are expensive and require very large volumes of space. According to the iniciative’s press release, alternative storage technologies, such as phase change materials (PCMs) and thermochemical materials (TCMs) are available on a laboratory scale. However, more research and development is needed before these technologies can be developed into commercial solutions.