What Is PERC Technology?

[Shoaib]

August 22, 2023 at 10:45 am

PERC technology to put pressure on traditional solar cells in supply chain
Strong global demand for higher-efficiency modules is driving the growth of PERC technology, like HJT and IBC that are expected to gain market share from 2017 onwards. PERC will become a mainstream technology by 2020, as it occupies the leading position among the competing new technologies. It is being increasingly adopted by top cell manufacturers upgrading part of their existing in-cell lines into PERC or booking orders for new PERC lines.

What are PERC solar cells?
PERC can stand for either Passivated Emitter and Rear Cell or Passivated Emitter and Rear Contact. At its core, a PERC solar cell is simply a more efficient solar cell, meaning that solar panels built with PERC cells can convert sunlight into usable electricity more easily. PERC solar cells typically perform better than traditional panels in both low-light conditions and high temperatures. PERC technology boosts efficiency through the addition of a layer to the back of a traditional solar cell, which provides several benefits to the cell’s production.

How are PERC solar cells different from standard solar cells?
A PERC solar cell is not much different in construction from a typical photovoltaic solar cell. Both types of solar technology use silicon wafers to generate a flow of electrons using incoming solar radiation, and the overall construction of the cell types is very similar. The main difference between PERC cells and typical monocrystalline photovoltaic cells is the integration of a back surface passivation layer, which is a layer of material on the back of the cells that provides three main benefits that boost cell efficiency.
How does a back surface passivation layer lead to gains in solar cell efficiency? Here are the three ways the passivation layer in a PERC solar cell increases overall efficiency:

1. Reflection of light back through the cell
A back surface passivation layer reflects light that passes through the silicon cell without being absorbed back into the silicon, giving the solar cell a second absorption attempt. This reflection of light means that more incoming solar radiation will end up being absorbed by the silicon cell, thus the cell becomes more efficient.

2. Reduced electron recombination
The addition of a back surface passivation layer reduces “electron recombination” in the solar cell. Simply put, electron recombination is the tendency of electrons to recombine, which causes a blockage in the free movement of electrons through the solar cell. This inhibition of free electron movement leads to less-than-optimal cell efficiencies. In a PERC solar cell, electron recombination is reduced in order to bump up efficiency.

3. Reduced heat absorption

The third benefit from a PERC solar cell is the reflection of certain wavelengths of light. A silicon wafer in a solar cell can only absorb light in wavelengths up to 1180 nanometers (nm), and higher-wavelength light waves pass through the silicon and are absorbed by the solar panel’s metal back sheet, creating heat. When solar cells are heated, they operate at lower efficiencies. The back surface passivation layer in PERC solar cells is specially designed to reflect light with a wavelength above 1180 nm, reducing the heat energy in the solar cell and consequently increasing efficiency.

PERC solar cell manufacturing
One of the biggest reasons why PERC technology can be so powerful is the minimal investment it takes to begin manufacturing PERC solar cells instead of standard monocrystalline solar cells. In order to produce a PERC cell,

Benefits of PERC technology for solar shoppers

Solar panels built with PERC technology allow for more energy-dense solar installations. This means that you can generate the same amount of energy using fewer PERC solar panels than they would with more standard solar panels. Consequently, by needing fewer solar panels for your installation, your costs can be reduced. Additionally, the fewer panels you need, the more flexibility you have on your roof to position your panels. If suitable roof space is limited, using PERC solar panels or any high-efficiency panel product can make a solar installation capable of the power you need a reality.
Reducing the number of solar panels you need has the added benefit of bringing down the balance-of-system (BOS) costs for your solar panel installation. BOS costs are generally any costs involved in solar installation components that are not the solar modules themselves. Inverters, racking and wiring all factor into your BOS costs, and the fewer panels you need, the fewer complementary components you’ll need as well.