the use of multi-layer polymer photovoltaic modules resistant to impact and hail

In several countries, building-integrated photovoltaics (pv) solutions could contribute to the growth of total installed pv capacity. however, in some circumstances, the relatively high weight (10-15 kg/m2) 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/m2) 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 back sheet by an innovative composite back sheet. a total of two module design contributions to impact resistance are highlighted: a global energy dissipation, mostly related to the back sheet properties; and a local energy dissipation, mainly related to the front sheet properties. these results clearly show that a balance between front sheet design and back sheet stiffness have to be found in order to maximize hail resistance and mechanical rigidity while minimizing the module s weight.