MiniStor: MiniStor-MINImal Size Thermal and Electrical Energy STORage System for In-Situ Residential Installation

The MiniStor thermal storage system is based on a high-performing thermochemical material (TCM) reaction, combined with a hot and a cold phase-change materials (PCM). The PCM’s use their latent heat during phase change to storage the heat and the cold produce from the TCM. The electrical storage is a conventional system based on a Li-ion battery for flexibility and usage year-round. The storage system allows for compact storing of RES-based energy using hybrid photovoltaic thermal panels (PVT).

This system includes a home energy management system (HEMS) that connects to the Internet of Things (IoT) to synchronise and efficiently manage the overall supply and demand at household level, responding for grid constraints and price signals.

The MiniStor system provides stability, performance and usage of at least 20 years with a minimal-size. The estimated storage material volume (TCM+PCM(hot)+PCM(cold) will be 0.72 m3. The overall system storage density is extremely high, up to 10.6 times higher than water-based storage systems for an operating heating temperature difference in the range of 15oC (around 182 kWh/m3). This system reduces the net energy consumption of a building by at least 44%, and will have an expected return-on-investment period of 6.7 years.


Buildings in the European cities need to improve their energy efficiency to contribute to the EU energy goals. One way is to store thermal energy through innovative solutions integrated into the existing structures. The EU-funded MiniStor project is developing an advanced compact integrated system that stores heat. The solution is adapted to existing building stock in EU cities and supplies sustainable heating, cooling and electricity storage. This system is fully innovative using solar-based renewable energy sources. Its management is secured by a building energy management system connected to the IoT. The project aims to significantly reduce energy consumption in residential buildings offering stability and high performance.

Link to the Project Website