No abstract

In several countries, building‐integrated photovoltaics solutions could prospectively contribute to the growth of total installed photovoltaic (PV) capacity as they enable electricity production with minimal impact on free land. However, in some circumstances, the relatively high weight (≥15 kg/m2) of existing glass/glass building‐integrated photovoltaics modules may constitute a barrier to the diffusion of PV in the built environment. With the aim of limiting the weight while preserving excellent mechanical stability and durability properties, we propose a new design for lightweight crystalline‐silicon (c‐Si) PV modules in which the conventional polymer backsheet (or glass) is replaced by a composite sandwich structure, and the frontsheet by a transparent polymer foil. Since sandwich structures are generally realized using epoxy as a gluing material, requiring long processing times, we further investigate (1) the possibility of using standard polymers used in the solar industry as alternative adhesives in the sandwich and (2) the possibility to considerably simplify manufacturing, using conventional lamination processes. Mini‐modules are produced, characterized, and submitted to accelerated aging tests (thermal cycling and damp‐heat) to assess the stability of the product against environmental degradation. We show that, by using the reference epoxy adhesive, it is possible to manufacture a lightweight (~5 kg/m2) mini‐module in a 2‐step process, which successfully passes a selection of industry qualification tests, including thermal cycling, damp‐heat, and hail test. We further show that, by replacing epoxy by a PV adhesive, we are able to considerably simplify the manufacturing process, while preserving excellent mechanical and durability properties.

No abstract

No abstract

A new in-situ moisture monitoring technique for PV modules is proposed using miniature digital humidity and temperature sensors. The sensors were embedded in three different ethylene-vinyl-acetate (EVA) stacks and proved to be resistant to lamination conditions. The fact that they are in direct contact to EVA does not affect their performance since their saturated relative humidity (RH) reading is proportional to the external RH in the air. By exposing the sensors to elevated temperature and RH conditions, water vapor transmission rate (WVTR) of the backsheet and diffusion coefficient of the EVA can be determined. Obtained coefficients agree with reference values within their measurement uncertainties. Besides determining material moisture ingress properties, this monitoring technique is also applicable for long-term outdoor PV module monitoring. It shall provide valuable location and installation specific information of RH and temperature stress conditions, especially as a feedback information to manufacturers of materials and PV modules.