The Real Value of Edge Passivation—and How Five Extra Watts Could Generate Millions

•6 min read

Final calculation… How much does EPD add to actual capacity?

The question that concerns all cell and solar panel manufacturers is:

How much real yield does edge passivation technology add?

The results of academic research and commercial production data suggest that the true value of this technology lies not in the manufacturing step itself, but in an integrated series of electrical improvements starting at the edge and ending with an increase in the nominal capacity of the solar panel.

This series runs in the following sequence:

Fixing Edge Defects Extending Lifetime of Minority Charge Carriers Increasing Open Circuit Voltage (Voc) and Fill Factor (FF) Increasing Cell Efficiency Increasing Final Solar Panel Capacity.

Results of Fraunhofer Institute ISE

The Institute Fraunhofer ISE The German is one of the most important scientific references in this field, where he assessed the performance of TOPCon cells after the application of the edge passivation technique (called in the study Passivated Edge Technology – PET).

The results showed that, whether traditional cutting technique is used LSMC Or thermal cutting technology. TLSthe Application of a Layer of Aluminum Oxide 8 Nm Using Technology ALDFollowed by a birthing process at 250°C, led to:

  • Absolute increase in cell conversion efficiency reached 0.5% Compared to the undiluted cut cell.

Long-term stability tests were also carried out. 11 monthsproved to be a layer. Al₂O₃ It maintained its chemical and electrical properties without any noticeable deterioration.

Thanks to the combination TLS And…PETThe efficiency of the final cell is about 22%After being cut from an original cell, it’s efficient. 22.08%While the best pieces have achieved efficiencies, 21.92% And…21.88%.

The researchers also note that the amount of improvement varies slightly depending on the location of the piece within the original cell, as the pieces on the extremities benefit to a different degree than those in the center.

Results of RS-ALD

Studies conducted by Chinese research institutions and companies have shown that the passivation of edges using RS-ALD Improves the most important electrical indicators of TOPCON cells.

the Best Operating Conditions200°C) The following results were achieved compared to non-velvet cells:

  • The open circuit voltage (Voc) increases by 1.7 mV per cell.

This reflects a lower rate of re-union of charge carriers and increased separation of semi-stable Fermi levels.

  • Fill factor (FF) increased by 0.23%.

This demonstrates the success of the edge passivation process in reducing leakage currents and improving the cell’s ideal coefficient.

  • Increase the absolute efficiency of the cell by 0.123%.

Although this increase seems small, it becomes of great value after the assembly of hundreds of cells inside the tablet.

What happens after the cells are assembled inside the board?

When the velvet cells are connected within the solar panel, the benefit is multiplied at the full system level.

Measurements showed that the finished board achieves:

  • Increase in Voc Tirana 0.11 Volts.
  • Improvements in FF Up to 0.37%.
  • Increase in nominal capacity 3.78 Watts.

These are figures of great economic importance in an industry that relies on very limited profit margins.

Commercial data… more than 5 watts extra

The benefits of edge passivation are not limited to laboratories.

Announced a company. Laplace, which supplies a number of large manufacturers with EPD production lines, the average increase in the capacity of panels manufactured using its integrated system amounts to:

5.2 watts per board.

This increase is broken down as follows:

  • Height Voc By 0.088 Volts.
  • A slight increase in The Palace Stream (Isc) Tirana 0.008 Amp As a result of improved utilization of effective space and reduced reflection.
  • A significant improvement in Fill Factor (FF) Up to 0.41%.

Why is a 5 watt increase so important?

In the solar panel market, products are often classified by their power intervals. 5 Watt.

For example:

  • 650 Watt
  • 655 Watt
  • 660 Watt
  • 665 Watt

Each move to a higher category allows the plant to sell the tablet at a higher price.

Therefore, the increase exceeds 5 Watt You may move the entire product to a new marketing category without having to radically change the product line.

With intense competition and low profit margins, this increase may represent the difference between a profit or a loss.

The benefit that many don’t talk about… improving hotspot resistance

The most important benefit of quadrant technology may not be increased efficiency, but improved security.

When a part of the board is exposed to the shadow because of:

  • Bird droppings,
  • or papers,
  • or dust accumulation,

A shading cell transforms from an energy-producing element into an electrical load that consumes power.

In conventional panels, high current forces the rest of the cells to pass through the shaded cell, placing them under a reverse bias bias.

In this case, the electrical energy is converted to heat according to Joule’s law, and the temperature of the affected area may rise within seconds to more than 200°CThis is known as a phenomenon. Hot Spots (Hot Spots).

This phenomenon may lead to:

  • Combustion of packaging material,
  • damage to the back glass,
  • shorten the life of the board,
  • In severe cases, it can cause fires at solar power plants.

Why is this less of a quadrant design problem?

When the cell is divided into four parts, the current passing in each part decreases to about quarter of the original current..

Since the heat produced is proportional to Current Box:

P = I²R

Reducing the current to a quarter would theoretically reduce the thermal capacity generated to about 1/16 Just compared to the whole cell.

Hot spot temperatures are thus much lower, especially in desert environments or areas with dense dust or mountainous terrain.

That’s why insurers and investors are starting to see quarter design as a way to improve the reliability of solar power plants and reduce long-term operational risk.

Conclusion

By 2026, it’s no longer a technology. Split the TOPCon cells into four quadrants With Laser Thermal Cutting (TLS) And…Passivating Edges (EPD) Just a way to address the defects caused by the pieces.

It has become an integrated technology platform that combines:

  • Increase the efficiency of the cell.
  • Increase the nominal capacity of the panels.
  • Improve the filling factor and open circuit effort.
  • Reduce resistance losses.
  • Support Techniques 0BB and high-density packaging.
  • Improve the reliability of operation.
  • Enhance the resistance of the hotspot phenomenon.

Today, these technologies are one of the most important pillars of the new generation of cell manufacturing. TOPConIt is the basis for balancing high efficiency, high productivity, and long-term reliability in solar plants at the gigawatt and terawatt levels.