Periodic Reporting for period 5 - MiniStor (Minimal Size Thermal and Electrical Energy Storage System for In-Situ Residential Installation)
Reporting period: 2024-11-01 to 2025-06-30
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.
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.
As an overview, the Consortium has manufactured and installed the five prototypes at the different demonstration sites. The fifth prototype was delayed due to difficulties in finding a suitable sized ammonia compressor as the original supplier went bankrupt, and its delivery that needed a sea crossing. However, in all demo sites the system has been installed and commissioned, and is currently performing according to the expected behaviour. The specific photovoltaic thermal (PVT) panels for Santiago de Compostela were installed, which is an unglazed model, and that also included an additional heat pump to upgrade heat from the start of the process.
Control systems have been based on feedback from potential users are being used as a SCADA system. Information from the prototypes is being collected in a data cloud solution. Problems were experienced with the compressor (sourced from third parties) which necessitated changes and repairs in most demonstration sites. Level gauges were also recalibrated as they were providing wrong measurements. These were corrected.
A methodology for exploitation and commercialization studies was developed, with key exploitable products detailed. Market studies in seven key European markets has been done. A proposition for the business model is to set up a "NewCo", as a startup that would bring the system to TRL 9 and commercialize it throughout Europe. The most promising markets were identified. Due to the high initial cost, the system can be commercialized as part of a lease agreement, with maintenance provided by the NewCo or a utility company as part of agreements with clients. The use of the system in larger-scale residential and residential-type settings was also explored. The market advantage of MiniStor is offering innovative thermal energy storage in a package that includes several technologies that would be difficult or more costly to integrate and optimize separately. Similar competitors have either much lower capacity (e.g. water storage tanks) or are still under development.
The dissemination strategies were carried out through the project website and professional social media channels, with several KPIs met or exceeded. The project was also presented at the CTN-100 committee on HVAC systems of the Spanish Standardization Association (UNE), which provided a milestone for demonstrating the cross-sectionality of different standards, as there is no single one that covers thermal energy storage.
A final conference was also held in Brussels coinciding with Sustainable Energy Week 2025, with a stand in the same event. Project members participated in different conferences (online and in person) and various open access peer-reviewed papers were published. Newspaper articles in both Ireland and Spain mentioning the project were also published. The project had approximations with sister projects of similar subject theme and has been included in the European Construction Technology Platform (ECTP) catalogue.
Control systems have been based on feedback from potential users are being used as a SCADA system. Information from the prototypes is being collected in a data cloud solution. Problems were experienced with the compressor (sourced from third parties) which necessitated changes and repairs in most demonstration sites. Level gauges were also recalibrated as they were providing wrong measurements. These were corrected.
A methodology for exploitation and commercialization studies was developed, with key exploitable products detailed. Market studies in seven key European markets has been done. A proposition for the business model is to set up a "NewCo", as a startup that would bring the system to TRL 9 and commercialize it throughout Europe. The most promising markets were identified. Due to the high initial cost, the system can be commercialized as part of a lease agreement, with maintenance provided by the NewCo or a utility company as part of agreements with clients. The use of the system in larger-scale residential and residential-type settings was also explored. The market advantage of MiniStor is offering innovative thermal energy storage in a package that includes several technologies that would be difficult or more costly to integrate and optimize separately. Similar competitors have either much lower capacity (e.g. water storage tanks) or are still under development.
The dissemination strategies were carried out through the project website and professional social media channels, with several KPIs met or exceeded. The project was also presented at the CTN-100 committee on HVAC systems of the Spanish Standardization Association (UNE), which provided a milestone for demonstrating the cross-sectionality of different standards, as there is no single one that covers thermal energy storage.
A final conference was also held in Brussels coinciding with Sustainable Energy Week 2025, with a stand in the same event. Project members participated in different conferences (online and in person) and various open access peer-reviewed papers were published. Newspaper articles in both Ireland and Spain mentioning the project were also published. The project had approximations with sister projects of similar subject theme and has been included in the European Construction Technology Platform (ECTP) catalogue.
The project achieved progress beyond the state of the art through development of an integrated and self-powered thermochemical energy storage system (TCM) assisted by phase-change materials (PCMs) and being able to store surplus electrical energy in a conventional lithium-ion battery (EESS) when using photovoltaic-thermal panels (PVT). The system is managed by a smart Home Energy Management System (HEMS). The offer of these systems as an integrated package makes it have a market advantage other technologies.
This was done through a complete set of calculations, the manufacture of the prototypes according to these calculations, and the demonstration in five residential sites across Europe with different climatic and economic conditions.
The main legacy of the project consists in demonstrating thermal energy storage has high potential for replication and leveraging the intermittency of renewable energy sources. This will impact positively our environment through reduced energy consumption for both thermal and electrical energy, lower dependency on imported fossil fuels, reduce energy poverty through allowing more households to integrate renewables, and improved control of residential built environment energy use and indoor air quality.
This was done through a complete set of calculations, the manufacture of the prototypes according to these calculations, and the demonstration in five residential sites across Europe with different climatic and economic conditions.
The main legacy of the project consists in demonstrating thermal energy storage has high potential for replication and leveraging the intermittency of renewable energy sources. This will impact positively our environment through reduced energy consumption for both thermal and electrical energy, lower dependency on imported fossil fuels, reduce energy poverty through allowing more households to integrate renewables, and improved control of residential built environment energy use and indoor air quality.