For those exploring solar technologies and planning to install a solar power system, gaining a clear understanding of different panel technologies is important. PERC is one such technology worth knowing about before making an informed solar investment.
In this blog, Neal Solar a leading solar panel company in Kerala, explains everything you need to know about PERC solar panels, how they work, and their key benefits.
What is a PERC solar panel
A PERC solar panel is a photovoltaic (PV) panel that uses Passivated Emitter and Rear Cell (PERC) technology to improve the efficiency of converting sunlight into electricity. It is commonly manufactured using crystalline silicon solar cells, with an additional passivation layer on the rear side of each cell to improve light utilisation and reduce energy losses.
In conventional silicon solar cells, some light passes through the silicon wafer without being absorbed, while some of the electrical energy that could be generated is lost through a process called recombination, in which electrons and holes recombine before contributing to the electrical current. PERC technology addresses these limitations by incorporating a specially designed rear-surface passivation layer that reduces recombination and reflects certain unabsorbed light back into the silicon.
This additional layer allows the cell to capture more usable solar energy and achieve higher conversion efficiency than conventional aluminium back-surface-field (Al-BSF) cells. PERC technology has therefore been widely adopted in monocrystalline solar panels for residential, commercial and utility-scale solar installations.
How PERC Technology Works
PERC technology enhances the performance of a solar cell through improvements in light absorption and the management of electrical charges. Unlike conventional Al-BSF solar cells, which have a full-area aluminium rear contact, PERC cells incorporate a rear passivation layer with carefully designed local contact openings. This structure helps reduce recombination losses and improves internal light reflection, allowing more of the absorbed sunlight to contribute to electricity generation.
Standard Light Capture
When sunlight reaches a PERC solar cell, photons enter the silicon wafer. Photons with sufficient energy generate electron-hole pairs, which are separated by the cell’s internal electric field to produce an electrical current. However, not all incoming light is absorbed during its first pass through the silicon.
Unused Light Escape
In a conventional solar cell, some photons pass through the silicon wafer without being absorbed. This limits the amount of sunlight available for electricity generation. Similarly, some electrons and holes recombine before contributing to the electrical current, reducing the cell’s overall efficiency.
Rear Reflection
PERC solar cells feature a dielectric passivation layer on the rear surface, which reduces recombination and improves internal light reflection. This layer reflects certain unabsorbed photons into the silicon wafer, while carefully designed local contact openings allow electrical connections to the rear metal contact. By improving light trapping and reducing rear-surface recombination, this structure helps enhance the cell’s overall efficiency.
Second Chance for Absorption
The reflected photons travel back through the silicon wafer, giving the cell another opportunity to absorb them and generate electrical charge. This extended optical path, combined with reduced recombination, helps PERC cells convert more sunlight into electricity than conventional Al-BSF cells.
Key Benefits of PERC Panels
PERC solar panels offer several performance advantages over conventional Al-BSF solar panels. Their improved cell architecture can support higher energy generation per unit of panel area, making them a practical option for various solar installations. However, actual performance depends on the panel’s specifications, installation conditions and overall system design.
Higher Efficiency
One of the primary benefits of PERC technology is its improved solar cell conversion efficiency. The rear passivation layer reduces recombination losses and enhances internal light reflection, allowing more sunlight to contribute to electricity generation. This enables PERC cells to achieve higher efficiency than conventional Al-BSF cells, although the actual efficiency varies by module model and manufacturer.
Low-Light Performance
PERC technology can improve light utilisation by reflecting certain photons into the silicon wafer for another opportunity to be absorbed. This can contribute to energy generation under diffuse sunlight conditions, such as cloudy weather or periods of reduced sunlight. However, PERC panels do not necessarily outperform every other solar technology in low-light conditions, as performance also depends on the cell design and module specifications.
Lower Heat Absorption
Although PERC technology is primarily designed to improve light utilisation and reduce recombination, some studies have demonstrated lower operating temperatures in PERC modules compared with conventional Al-BSF modules under specific test conditions. This can be attributed partly to the PERC cell’s higher rear-side reflectivity, which can reduce heat generation within the module. However, this does not mean that all PERC panels operate at lower temperatures. Actual operating temperatures and temperature-related power losses depend on the module’s construction, temperature coefficient, ventilation and installation conditions. Therefore, buyers should compare the manufacturer’s temperature coefficient and module specifications rather than assume that PERC technology inherently results in lower operating temperatures. H3:Space Savings
PERC panels can generate more electricity per unit of area than conventional Al-BSF panels, depending on their respective module efficiencies. This makes them useful for rooftops with limited installation space, where maximising the power capacity within the available area is important. By choosing a suitably efficient PERC module, homeowners and businesses may be able to meet their energy requirements using fewer panels than they would need with lower-efficiency alternatives.
Conclusion
PERC solar panels represent an important advancement in crystalline silicon solar technology, offering improved light utilisation, reduced recombination losses and higher conversion efficiency than conventional Al-BSF cells. Their potential for greater electricity generation per unit of area makes them a useful option for residential and commercial solar installations, particularly where rooftop space is limited.
Understanding the technology behind solar panels is an important step towards choosing a suitable solar power system. As a leading solar company in Kerala, Neal Solar helps customers explore solar solutions based on their energy requirements, available rooftop space and installation conditions. By evaluating panel efficiency, temperature coefficients and overall system specifications, you can make a more informed decision about your solar investment.
