SAM.SSA aims at developing new phase change materials for thermal energy seasonal storage applications in the range of medium temperatures. The generated materials are expected to provide:

  • Low cost, environmentally sound and safe solutions for seasonal storage applications
  • Easy adjustment of the melting point for optimal "tuning" to the required applications
  • Energy densities greater than 200 kWh/m3 and, consequently, compact storage
  • Long-term storage with significant reduction of thermal losses
  • Storage heat release at "high" temperature with, consequently, reduction of discharge power requirements.

The most significant application is space heating (i.e. for commercial or residential buildings) in winter using the energy collected during summer by thermal solar collectors.

The central idea of the project derives from recent research the project partner CNRS-I2M has carried out on sugar alcohols. They show that molecular alloys based on sugar alcohols are very promising for reaching compact seasonal storage with low thermal losses.

Science and Technology (S/T) Objectives

Based on the central idea and concept of the project the main S/T objectives are:

  1. To develop stable Molecular Alloys based on Sugar Alcohols (MASA) melting at medium temperatures (70-150°C, with emphasis on MASA melting at temperatures <100°C), providing high energy density (> 200 kWh/m3), showing significant and stable undercooling, and with high crystallization kinetics.
  2. To develop Carbon/MASA hybrid materials with increased thermal conductivity, high energy density and significant and stable undercooling. Solutions based on both graphitic foils and carbon foams will be investigated. Tailor-made, low-cost host porous materials as well as different inexpensive techniques for reaching super hydrophobic carbon surfaces will be developed.
  3. To develop appropriate MASA encapsulation for seasonal storage applications. Macro- and micro-encapsulation using organic, organic-inorganic hybrid polymer and inorganic shells will be investigated and optimum solutions for seasonal storage applications will be proposed.
  4. To propose efficient methods for meta-stability break off and materials' discharge. Simple solutions based on either thermal shocks or ultrasound will be investigated and proposed.
  5. To obtain a deep understanding of meta-stability, nucleation and crystallization phenomena, and to develop theoretical, numerical and experimental tools to guide materials synthesis, to identify key parameters for successful meta-stability break off, and to evaluate materials' performances.
  6. To provide verification of the stability and complete characterization of the developed materials (MASA, Carbon/MASA, Encapsulated MASA) as well as performance evaluations for significant seasonal storage applications and cost and environmental issues analysis.
  7. To identify further R&D required for materials improvement and to define a strategy for industrialisation of most promising ones.