Author(s)

MATTHIEU HORGNIES, FABIENNE LEGRAND, EMMANUEL BONNET, ISABELLE DUBOIS-BRUGGER

Abstract

The last generations of solar cells are known to promote the use of renewable energies thanks to their higher efficiency and better aesthetics. However, the recent developments of the Building-Integrated Photovoltaic cells (BIPV) requires the installation of photovoltaic panels on the vertical façade of residential and office buildings (and not only on their roofs) in order to produce more electricity and to reduce the seasonal mismatch between the production and the consumption of electricity. In this case, researches were done to use concrete as a direct support of the solar cells and/or photovoltaic film (in the place of common structures based-on glass or metal). Experiments were performed to establish if the ultra-high-performance fibre-reinforced concrete (UHPFRC) could be a good candidate to manufacture aesthetical façade panels functionalized by photovoltaic cells. A technical process that can be described by pouring the fresh concrete directly on the backside of the photovoltaic cells, previously placed at the bottom of the formwork and coated by specific adhesives, was developed and patented. A broad range of methods and accelerated tests (observations by optical and scanning electron microscopy, adhesion and bending flexural tests, UV aging and water condensation tests, freeze-thaw cycling, etc.) was used to study the interface between photovoltaic components and concrete, and to establish if the adhesion could be durable. The results highlighted that the multi-layer technique, composed of flexible photovoltaic cells, structural adhesive and UHPFRC is a durable composite after hardening, which can resist to a broad range of environmental aggressions.

Keywords

adhesion, mechanical tests, durability, photovoltaic, concrete, interface