Kuraray's PVB film makes PV modules lighter and cheaper
The joint development of a PVB film for photovoltaic module encapsulation with AIST has led to superior long-lasting durability and a frameless, thinner design
Kuraray Co., Ltd. through joint research with the National Institute of Advanced Industrial Science and Technology (AIST) have developed high-durability encapsulant polyvinyl butyral (PVB) films.
They help to make photovoltaic (PV) modules lighter and less expensive, and Kuraray has begun sampling the films in test markets.
Figure 1: The structure of CIGS thin-film PV modules.
Left: Structure using existing encapsulants, Right: Structure using the new PVB encapsulant
Background for Development:
With the recent rise in demand for renewable energy, there has been a sudden increase in the installation of PV panels on residences and the construction of large-scale solar power plants, causing demand for PV modules and their components to also expand.
For PV modules, demand is rising for improved reliability in harsh environments, lower installation burdens and better usability through lighter designs, as well as reductions in cost.
Amid these circumstances, we developed a high-strength, high-durability PV module encapsulant PVB film that can reduce costs and weight by simplifying PV module structure.
Encapsulants for PV modules are materials used to encase or cover electrodes, wires and other (interior) components as well as the PV cells that generate electricity. They play the important role of protecting the interior from water and shocks while helping to keep output from degrading due to breakage and age.
Figure 2: Damp heat test of a-Si thin film PV modules according to IEC61646 (tested in joint research with Research Centre for Photovoltaic Technologies, AIST by the "Consortium Study on Fabrication and Characterization of Solar Cell Modules with Long Life and High Reliability"). The module using this new PVB film had no degradation after 10,000 hours
High encapsulant performance eliminates the need for using edge seals on the PV module to help stop water from leaking inside. Also, because of PVB’s high modulus, the weight of the load is decreased, flexure in the glass is reduced, and the module’s strength is maintained.
Kuraray was able to forgo the use of module edge seals as well as the frames and supports previously used to augment the module’s strength due to the features mentioned above. This development reduced costs thanks to the simpler and lighter design.
What's more, Kuraray says its PVB superior long-lasting durability doesn’t degrade with age unlike current encapsulant materials. Also, the new PVB film is highly resistant to Potential Induced Degradation (PID) which has become a more prominent concern recently.
Kuraray is scheduled to present the aforementioned product with Kuraray Europe GmbH and AIST at the 28th European Photovoltaic Solar Energy Conference and Exhibition held in Paris, France, between September 30th and October 4th.
With this newly developed encapsulant, Kuraray will work to further expand and popularise PV panel usage.