Hikari: the first energy-positive block in Europe
The necessary energy transition of our society is prompting the search for innovating technological solutions. Public-sector development company SPLA Lyon-Confluence launched a competition to build an energy-positive building: a challenge taken up by setec bâtiment, Kengo Kuma & associates and Bouygues Immobilier with the Hikari project.
Consisting of three buildings on 12,000 square metres, this futuristic block is the first energy-positive development in Europe and the only eco-neighbourhood in France supported by the World Wildlife Fund (WWF). Once the energy needs had been reduced, the aim above all, for setec bâtiment and its team, was to maximise the renewable energy resources.
The bioclimatic architectural design, centred around light, provides control of energy needs. Pooling of the energy systems of the offices, apartments and shops, along with energy storage, compensates the intermittent character of the renewable resource. Large-scale storage of the cold produced night and day by an absorption chiller is accomplished, in a world first, using a specific phase change material. Melting of this material, which freezes at 5 degrees, restores a reserve of cold on demand used for summer cooling of the premises. The other storage systems (heat, electricity) coupled with sophisticated recovery systems, a heat pump, solar energy and plant-oil-fired trigeneration enable the required energy balance to be achieved.
Control energy consumption
Although the Hikari project gives priority to renewable energies, it is also part of the Smart Grid movement, using information technologies to optimise energy production, distribution and consumption. Installation of the latest sensors throughout the buildings gives the occupants access to all the data on their environment and enables them to interact with it. Their comfort is a priority, so thermal comfort is controlled according to the perceived temperature.