Robust Glass-Free Lightweight Photovoltaic Modules With Improved Resistance to Mechanical Loads and Impact

Abstract

In several countries, building-integrated photovoltaics (PV) solutions could contribute to the growth of total installed PV capacity. However, in some circumstances, the relative high weight (10-15 kg/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) and lack of aesthetics of PV may constitute a barrier to its diffusion. In this work, we propose a glass-free lightweight solution (≃6 kg/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) compliant with hail and mechanical load tests as prescribed by the IEC 61215-2:2016. The low weight is achieved by substituting the conventional glass cover with a polymer multi-layer resistant to hail impacts and the conventional polymer/glass backsheet by an innovative composite backsheet. A total of two module design contributions to impact resistance are highlighted: a global energy dissipation, mostly related to the backsheet properties; and a local energy dissipation, mainly related to the frontsheet properties. These results clearly show that a balance between frontsheet design and backsheet stiffness have to be found in order to maximize hail resistance and mechanical rigidity while minimizing the module's weight.