A critical component often overlooked in the realm of solar panels is the backsheet – a protective layer situated on the rear side of the PV module. This layer plays a pivotal role in safeguarding the solar panel from an array of environmental factors that can potentially compromise its performance and lifespan.
When shopping for solar panels, it’s essential to be familiar with some common types of backsheets: white, black, transparent, aluminium, and copper.
In this blog post, we will delve into the details of copper backsheets.
Understanding copper backsheet
The copper backsheet incorporates a layer of copper foil as its topmost or innermost layer. This construction gives it a visual resemblance to traditional backsheets when attached to a PV module. However, hidden beneath this unassuming exterior is a copper foil, which serves as a conductive layer, facilitating the flow of electrons generated by the solar PV cells.
In other words, the copper backsheet provides a low-resistance path for electrons to flow from the cells to the electrical connections, which helps improve the efficiency of the solar panel.
When is a copper backsheet used?
To appreciate the significance of a copper backsheet, it's crucial to understand the different types of passivation in PV cells.
Passivation can occur on both the front and rear sides or only on the rear side of the PV cell. Commonly, we encounter two types of PV cells: monofacial and bifacial cells. Both of these cells undergo passivation on the front and rear sides.
The copper backsheet steps into the spotlight when dealing with a specific category of solar cells known as Metal Wrap Through (MWT) solar cells, which are rear-passivated. The inherent conductivity of copper makes it the ideal choice for MWT solar cells, allowing for the efficient transfer of electrons from the rear-passivated cells.
Data credits:
RenewSys R&D
Image credits:
RenewSys