The SWS HEATING ambitions at different levels are summarises as follows:


  • Reach compact solutions that can be integrated in new or existing buildings .

  • Potential to reduce system cost by up to 20-30% compared to other solar seasonal storage units .

  • Optimised system design and sizing for achieving very high solar fraction - i.e. the amount of energy provided by the solar technology divided by the total energy required for domestic heating and hot water throughout the year -  of over 60% in south, central and north Europe.

  • Validation of SWS-heating system in an intended environment (TRL5) and preparation of its further development stages

From idea conception to commercialisation
SWS-Heating: From idea conception to commercialisation

At material level

  • Develop a family of advanced SWS-materials with tailored sorption capacity adapted to typical working conditions of the sorption module .

  • Achieve very high heat storage density, in the range of 1.1-1.3 GJ/m3 (over 30% higher than the best SWS sorbent material and 40-60% than state of the art for the same temperature range) that would allow reaching compact seasonal storage solutions .

  • Validate the stability of the new sorbent material against hydrothermal cycling under severe working conditions, up to 1,000 cycles that correspond to more than 50 years of operation, with at least 10 charging/discharging cycles per year .

  • Evaluate enhanced STES capacity of the developed SWS, and prove the low production cost potential to less than 5 €/kg at commercial level, according to estimated cost of raw materials (currently it is about 10 €/kg for the delivery of few quantities).

At component level

  • Optimisation of dedicated HEX based on plate technology, embedding optimised SWS grain size to enhance the durability, the heat storage density and the heat transfer characteristics.

  • Experimentally & numerically analyse main parameters affecting evaporation & condensation under low pressure water vapour conditions, and develop optimised HEX components.

  • Develop new glass tubes with vacuum and a fluid absorber to be included in a solar thermal collector to reach high efficiency and low cost.

  • Develop a small vacuum combi-storage that minimises thermal losses and has the potential to reach a competitive cost compared to standard hot water tanks.

  • Design a PCM-based thermal buffer tank and adjust the operational aspects of the backup heater, focussing on their dynamic response, when combined with the vacuum tank.

At control level

  • Development of control unit to manage the system modes according to supply/demand balance.

  • Optimisation of system operation during charging/discharging phases by automatic switching of heat supply between the SWS-heating system and the backup heater.

  • Adopting EE strategies to achieve maximum solar energy exploitation and reach the targeted SF.

  • Option for integration to BEMS for overall facility management & heating demand optimisation.

  • Enable services for: (1) preventive and restoring maintenance, (2) user-friendliness operation, (3) adjusting operation according to weather forecasts, and (4) remote operation and reporting.