Adhesives for Solar Energy
Photovoltaic energy has evolved to be a very significant source of electrical power. It is now possible to manufacture large scale, durable, thin film silicon and/or germanium alloy materials with excellent electrical and optical properties, and in many instances superior to their single crystal counterparts. Despite the advances made in photovoltaic roofing materials, there is still a need for a photovoltaic building material which is light in weight, flexible enough to be installed over irregular surfaces without the use of significant numbers of fasteners and hardware. As an alternative to mechanical fasteners, properly chosen structural adhesives offer the benefits of environmental resistance, reduced stress points, leaks and corrosion along with enhanced sealant properties.
New technologies allow a low cost, flexible photovoltaic building material which is lightweight, self-adhesive, and which can be easily attached to a variety of building structures. The encapsulant material comprises a polymeric material like fluoropolymers, ethylenevinylacetate, and combinations thereof having glass fibers disposed therein.The material can also be shipped in a rolled form. In addition, the material has a low flammability and can also be configured to include firebreak structures which limit flame spread, thereby reducing the insurance rates.This material can also be used in vehicles, consumer products applications. The photovoltaic building material further includes contact adhesive, often covered by a sheet of release material, which is used to affix the module onto a building structure. The contact adhesive comprises a rubberized asphalt. The substrate may be any typical roofing material such as metallic foils, polymeric membranes, and polymer impregnated fiber mats.
There is a new way of manufacturing solar panels using a conductive, thermosetting heat-activated adhesive. Once the adhesive is cured by the heat, it permits electrical conductivity between the individual solar cells within the completed panel and provides mechanical coupling between cascaded strips.
The overall installed cost (e.g. system plus labor) of a solar system can be reduced with an adhesive, non-penetrating, non-racking light-weight crystalline silicon solar panel system that can be installed very quickly.
Acrylic based electrically conductive pressure sensitive adhesive tapes, in combination with tin-plated copper foil are used in thin film solar applications. Acrylic chemistry allows long-term outdoor durability against heat and UV. Unlike solvent based and other liquid adhesives, no curing is required and the tape can be applied at high speed and productivity with automation equipment.
References:
“New adhesive solar module makes case to eliminate racking”, by K. Pickerel October 4, 2016 – https://www.solarpowerworldonline.com/2016/10/new-adhesive-solar-module-makes-case-eliminate-racking/
“Self-adhesive photovoltaic module”, US6553729- https://patents.google.com/patent/US6553729
“Systems, method and apparatus for curing conductive paste”, US9748434- https://patents.google.com/patent/US9748434B1/en