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Multifunctional renewable energy

European researchers are developing a device that stores and uses solar energy to provide both hot water and mechanical ventilation for multifamily houses. Moreover, an app linked to the machine monitors the users’ energy consumption.


Nowadays households wanting to switch to solar energy have to deal with variability over time. In addition, if they are part of a condominium, the ability to store solar energy in an apartment without taking up significant living space is a big issue. A solution may come from a device developed by the EU project BuildHeat, which is testing new technologies for the energy retrofit of multifamily houses. It is a “storage tank with a mechanical ventilation unit integrated on top.” Engineer Roberto Fedrizzi, who coordinates the international research team, explains how it works. Can you describe this multifunctional device? The middle part of the structure stores thermal solar energy. It contains enough hot water to cover a family of four in their daily use. The bottom part of the unit is equipped with a computerised system that decides autonomously when it is the best time to store solar energy and distributes clean hot water in the apartment. The upper part of the device uses the same solar energy to operate the fans of a mechanical ventilation system, which introduces fresh filtered outdoor air into the apartment. It is a double flow ventilation. Depending on the season, these units can preheat or refresh the external air before blowing it inside. Is the installation of this device user-friendly? The hot water tank and the ventilation system are mounted on the same metallic frame. Since the unit is assembled in the factory, installation is simple: it is fast and does require minor masonry work. Moreover, industrialisation means that devices are produced with a very limited thickness – around 25 centimetres – that can be fixed on a wall in a closet or on a balcony in mild climates. And what about the monitoring system? The device allows the user to instantly count the thermal consumption of the apartment and make it available on an app on your smartphone, which constantly communicates with the system. This tool, developed by the BuildHeat researchers, allows tenants to be aware of their energy consumption habits. The goal is to improve people’s energy consumption behaviours. When will this technology enter the market? The researchers of the project, who are not pure scientists but work for companies engaged in product development, are trying to build collaborative agreements to put a unique product on the market. Nowadays numerous technologies for energy efficiency are available, but each of them thinks for itself. One of the objectives of the project is to integrate, to bring together different technologies, optimised and with single devices from different companies working together. In my opinion, the market will evolve from a single unit logic to a system logic. This will produce very significant and quantifiable energy savings in the future. By Claudio Rocco


renewable energy, solar energy, buildings, boiler