1. Thermal energy storage (TES) technologies like phase change materials (PCMs), sorption, and thermochemical materials can store solar and renewable heat for use when needed. 2. PCMs use the heat of phase change during melting and freezing to efficiently store and release thermal energy. Organic PCMs like paraffin wax are promising due to their high storage density and melting temperatures around human comfort levels. 3. Sorption technologies use physical or chemical bonding to store heat in materials like silica gels, zeolites, or chemical reactions. A demonstration used zeolite to store nighttime heat from district heating for use during the day.

1. Compact Thermal Energy Storage Wim van Helden Webinar Leonardo-Energy 23 Jan. 2009

3. PRIMARY ENERGY USE FOR HEATING PURPOSES EU energy consumption

6. Stage of development of TES technologies TCM (chemical) Research Sorption (latent) Development PCM (latent) Demonstration Water (sensible) Mature market

8. Classification of Thermal Energy Storage

12. PCM Energy stored as function of temperature

13. Latent heat storage in PCMs PCM interesting at small temperature difference (around melting temperature) Left: volume of water and of TH29 needed for storage of 1 MJ heat. Right: mass of water and of TH29 needed for storage of 1 MJ heat. Volume water and TH29 for 1 MJ storage 0 5 10 15 20 25 0 - 100 10 - 60 15 - 40 20 - 30 temperature difference (°C) litres water TH29 Mass of water and TH29 for 1 MJ storage 0 5 10 15 20 25 0 - 100 10 - 60 15 - 40 20 - 30 temperature difference (°C) kilograms water TH29

15. Latent heat storage in ice Storage tanks for water filled polyethene balls, 2 projects in United States

17. Organic PCMs Left to right: - powder: 60% paraffine and silica material - granulate: 35% paraffine and diatomee earth - boards: 65% paraffine and wood fibre board New development. Compound: 80% paraffine, for direct contact with water, for instance in reservoir

19. Phase change Materials in walls development project with the partners BASF, caparol, maxit and Sto with Fraunhofer ISE 1/1999 - 9/2004 funded by BMWi FKZ 0329840A-D

20. measurements two identical rooms measured without and with two PCM products monitored one year each result: - 4 K difference reached - night ventilation essential

21. Since 2004 several products: Different products with microcapsules: plaster, plasterbords, porous concrete… ….. Different macrocapsules: Dörken, Rubitherm, SGL, Climator and others BASF: micronal SmartBoard™ Other systems: Energain, Rubitherm granules Foto: BASF

22. Latent heat storage: inorganic PCMs PCM can of Climator: typically applied in transformer rooms and telecom installations Nodule of Cristopia: HDPE ball filled with eutectic salt

42. IEA Task/Annex 42/24 Matrix approach