AGC Glass equips 570 m2 of photovoltaic facade of the first positive energy urban island in Europe

The new Hikari complex was designed by the Japanese architect Kengo Kuma for Bouygues Immobilier SLC Pitance and is the first positive energy urban island in Europe.

The first positive energy mixed island in Europe, Hikari displays exemplary environmental performance. A first made possible, among other things, by the integration of 570 m2 of AGC SunEwat XL photovoltaic glazing, which produces some 15 Mwh annually (total installed power = 25 kwp).

To achieve this high level of performance, the Hikari designers used the best of bioclimatic architecture techniques, but also skillfully mixed offices, housing and shops on the ground floor, in order to optimally manage the various uses and cycles of energy use. "Hikari's main innovation is based on the pooling of the energy produced," explains Ana Vidal-Andujar, Director of Real Estate South-East of the Bouygues group, who worked in partnership with NEDO, the Japanese public agency for the promotion of new energies and industrial and environmental technologies (equivalent to Ademe).

Mixing energies perfectly for high energy efficiency, the 3 buildings integrate 3 sources of renewable energy production. Thus, in addition to the 570 m2 of photovoltaic panels integrated into the facades of the dwellings, Hikari is equipped with a photovoltaic plant on the roof, a geothermal system and a cogeneration plant.

It is also planned to pool the energy consumption and production of the 3 buildings through an energy communication network. Offices and housing do not have the same energy cycles, the excess energy produced is stored and returned during hours of high demand thanks to a fuel cell.

It should also be noted that an ingenious battery storage system also makes it possible to respond to power outages or consumption peaks. In addition, the cooling needs of offices and shops are covered by an “absorption machine”, which produces chilled water from the heat of cogeneration and the cold of the groundwater.

Finally, a geothermal system contributes to cooling by drawing freshness from the waters of the Saône. Result: Hikari consumes 50% to 60% less than the standards of current thermal regulations and produces an amount of energy greater than its own consumption, around 0,2%.

Hikari, glazing side

Eager to be fully integrated into the line of the urban plan of the Herzog & de Meuron cabinet, the architect Kengo Kuma created parallelepipedic constructions with large notches which sculpt the facades of glass, wood, aluminum and stone: the guarantee of an optimal supply of natural light in the heart of interior spaces and a comfort of life. It should be noted that these buildings indeed display exceptional luminosity, in particular thanks to their large glazed areas.

Outside, the envelope of the buildings, treated on a stapled facade, adapts to the course of the sun, while absorbing and controlling light radiation and their energy contributions. The glazing thus ensures the double function of railing and energy production by integrating photovoltaic cells.

These intelligent glazings must also make it possible to reduce the solar intake in the adjacent living spaces while providing great visual comfort for the occupants. "The location of the photovoltaic cells has been adapted to meet this double demand from the architect," said Frédéric Bonnefoy Product Manager Active Glass. And to continue "According to the projects, the solutions differ in particular in thicknesses and types of glass, in dimensions, in the choice and the positioning of the cells", adds Frédéric Bonnefoy. And to conclude: "Tailor-made, allowing AGC to offer the flexibility that architects need today ..." The innovative character is present, at the same time, in the implementation of stapled glazing photovoltaic panels of large dimensions and in the unique location of photovoltaic cells thus meeting the aesthetic and functional requirements of the architect Kengo Kuma.

Financed by Bouygues Immobilier and NEDO, Hikari represents a higher cost than that of traditional buildings. The whole of the design and construction amounts to 60 million euros with a price per square meter of housing equivalent to that of the beautiful districts of Lyon.

AGC SunEwat XL

Equipped with photovoltaic cells incorporated between two sheets of glass, this AGC range of laminated safety glass optimizes a building's capacity to produce as much energy as it consumes. The interior glass offers many possibilities of finishes (clear, highly transparent, colored glass ...) while the exterior glass generally remains in low iron content glass to optimize the production of electricity. SunEwat XL can be integrated into any type of product (canopy, facade, balustrade) and adapts perfectly to all the sizing needs of the modules, leaving great freedom to creativity. The modules can be designed by combining an infinite number of aesthetic possibilities in order to obtain the most efficient energy production possible while adjusting the light transmission (by modifying the distance between the cells). Finally, note that SunEwat XL claims effective performance even at high temperatures and integrated in non-ventilated sills.

Hikari: identity card

a 5.500 m² office building, named “Higashi” (“East” in Japanese)
36 apartments on 3.400 m² of surface, in the “Minami” building (“South” in Japanese)
a mixed-use building named “Nishi” (“West” in Japanese), comprising offices (2.600 m²) and 4 roof villas (700 m²)
1.000 m² of shops on the ground floor of the 3 buildings.