Photovoltaic panel eaves edge sealing shape diagram

Why do photovoltaic devices have edge seals?

Because of the sensitivity of some photovoltaic devices to moisture-induced corrosion, they are packaged using impermeable front- and back-sheets along with an edge seal to prevent moisture ingress. Evaluation of edge seal materials can be difficult because of the low permeation rates involved and/or non-Fickian behavior.

Should you add a desiccated butyl edge sealant to a PV module?

Learn the benefit of adding a desiccated butyl edge sealant to the photovoltaic (PV) module package by examining the impact of desiccant on moisture breakthrough time and the test results demonstrating adhesion to qualify as a cemented joint. PV module packaging materials have a tough job.

What is D in PV encapsulant and edge seal?

where D is the diffusivity, elapsed time, and Csat saturation. Several PV encapsulant and edge seal materials were examined using Ca-film-based test specimens. Photographs of two examples are shown in Fig. 2 to demonstrate the extreme differences among encapsulant materials.

Are epoxies a good edge seal material?

Other edge seal materials (e.g. epoxies) can have very low diffusivities, but they are hard and brittle and could easily crack or delaminate in a large module. The mechanics and logistics of measuring moisture penetration through a free-standing film of an edge seal material can be very difficult.

How much permeate does an edge seal have?

The amount of permeate is very low. Ideally one will not reach steady state. An edge seal width of 1 cm can be capable of keeping moisture out for 20 years in almost any climate. Delamination is the main concern for edge seal performance. Edge Seals should be assembled without edge pinch to ensure good adhesion.

How durable is an edge seal?

To really evaluate the durability of an edge seal in a given application the nuances of the mechanical attributes of module construction must be accounted for. The edge seal is not providing mechanical strength but simply needs to maintain its position in the module after the application of thermal and mechanical stresses.