The EU building stock has large potential to increase its energy efficiency with solutions that can be integrated to existing dwellings and through different measures. One of them is optimizing the use and management of thermal energy by allowing it to be stored, levelling demand peaks and increasing use of renewables affected by intermittency such as solar-based heating. This will help decarbonize the generation of heat and help achieve overall national targets to offset climate change.
The MiniStor project aims at designing and producing a novel compact integrated thermal storage based on thermochemical materials to achieve sustainable heating, cooling and electricity storage that can be adapted to existing systems in residential buildings. It is based on a reaction of calcium chloride and ammonia, combined with parallel hot and cold phase-change materials for flexibility and usage year-round. It also stores electrical energy in a lithium-ion battery that responds to grid signals and can sell to the electrical grid. The system is managed by a Smart Home Energy Management System (SHEMS) that connects to the Internet of Things (IoT).
The system can have as input energy obtained from a variety of renewable energy sources such as hybrid photovoltaic thermal panels that collect both electricity and heat from the sun. This arrangement is demonstrated and validated in four demonstration sites (Ireland, Spain, Greece and Hungary), testing its effectiveness at different local climatic conditions and facilitating market replication.
As a conclusion for the action, it was found that thermochemical energy storage has great potential for application in residential applications. New technologies can provide much smaller footprint than previous propositions and provide large storage densities. However, regulatory developments must inform on new technical and manufacture practices, which mandate industry levels of safety which can be onerous for large-scale residential use. At the same time, one of the caveats of the system is that it needs an extended area for the solar resource. Possible commercialization pathways include its application in large-scale residential or residential-type uses, such as apartments, hotels, etc. This can also optimize maintenance costs. Another proposition is to commercialize the unit through a startup, or as part of the offer from utility companies, where the units are leased. This can also reduce maintenance costs for the user.