Differences Between Class A and Class B Solar Panels

Photovoltaic (PV) panels are commonly classified into Class A and Class B based on appearance quality, manufacturing tolerance, and power consistency. Both types can operate normally, but Class A panels follow stricter quality standards, especially for export markets and high-end installations.

1. Appearance and Visual Consistency

Color Consistency

Class A: The color of cells within the same module must be uniform and visually consistent.
Class B: Slight color differences between cells are allowed.

Notches (Cell Edge Defects)

V-shaped notches

Class A: Not allowed
Class B: Maximum 1 notch per panel, size < 1.5 × 1.5 mm

U-shaped notches

Class A: Maximum 1 notch per panel, size < 1.5 × 1.5 mm
Class B: Maximum 2 notches per panel, size < 2 × 2 mm

Perforations
Not allowed in both Class A and Class B.

2. Grid Line Quality

Broken Main Grid Lines
Not allowed in either Class A or Class B.
Broken Fine Grid Lines

Class A:

Length < 1 mm
No more than 2 per group
No 3 consecutive breaks

Class B:

Length < 2 mm
No more than 4 per group
No 3 consecutive breaks

Grid Line Oxidation

Not allowed for both grades.

3. Surface Defects

Front Surface Scratches

Class A:

Length < 2 mm
Width < 0.05 mm
Depth < 0.05 mm
Max 2 scratches per panel

Class B:

Length < 4 mm
Width < 0.05 mm
Depth < 0.05 mm
Max 2 scratches per panel
Back Aluminum Damage

Class A:
Size < 2 × 2 mm, max 1 damaged area

Class B:
Size < 3 × 3 mm, max 1 damaged area

4. Electrical Performance

Both grades must meet the agreed power rating, with a negative tolerance generally less than 0.1 W.

However:

Class A panels typically have better power consistency and tighter performance distribution.
Class B panels may have slightly larger power variation between cells.

Other electrical indicators such as reverse current limits and aluminum bead height are generally controlled within the same acceptable ranges.

5. Manufacturing Standards

Class A modules require stricter manufacturing control, including:

Consistent cell color and gloss
Precise alignment of solar cells
Strict spacing between cells
Higher material quality standards (e.g., thicker backsheet)

Class B panels usually use similar materials but allow slightly larger visual and manufacturing tolerances, making them more cost-effective.

6. Market Applications

Class A panels

Export markets
Commercial and utility-scale projects
High-quality residential installations

Class B panels

Cost-sensitive markets
Domestic installations
Budget-oriented solar projects

Conclusion

The main difference between Class A and Class B photovoltaic panels lies in appearance standards and manufacturing tolerance rather than basic functionality. While Class A panels offer better visual consistency and tighter quality control, Class B panels remain a reliable and economical option for many solar applications.