BC (Back Contact) Modules
All electrodes on the rear. No grid loss. 24-25%+ efficiency.

Back Contact (BC) is a solar cell architecture where all electrical contacts — positive, negative, and current-collection grid — are placed on the REAR side of the cell. Conventional cells (PERC, TOPCon, HJT) have front-side bus bars and grid lines that block sunlight (typically 3-5% shading loss). BC eliminates this shading entirely, enabling 24-25%+ module efficiency vs 22-23% for TOPCon/HJT. The manufacturing is more complex, which is why BC costs 15-20% more — but for premium applications, the extra efficiency + aesthetic often justifies the premium.

BC is a family of architectures; IBC (Interdigitated Back Contact) is the most common variant, where positive and negative contacts are interleaved (interdigitated) on the rear. Other BC variants include HBC (Heterojunction + Back Contact), which combines BC architecture with HJT's amorphous/crystalline silicon passivation for the highest combined performance. JUSTSOLAR BC 680W uses the latest HBC architecture — combining both technologies.

Depends on the project. Choose BC when: (1) aesthetics matter — premium residential, BIPV, architectural projects; (2) land or roof area is constrained — BC's higher power density directly reduces BOS cost per kW; (3) project is in a low-light / high-latitude market where BC's spectral response is advantageous; (4) lifetime yield matters more than upfront cost — BC's lower degradation compounds over 25 years. Choose TOPCon when: you're optimizing for $/W on ample-space utility projects where simple power output per dollar wins. For most utility-scale projects, TOPCon remains the cost-optimized choice.

Both BC and HJT have excellent temperature coefficients. HJT is the gold standard for hot climates with -0.24%/°C — the best in commercial production. BC is close at -0.26 to -0.28%/°C — still much better than TOPCon (-0.30%/°C) or PERC (-0.35%/°C). For Saudi Arabia, UAE, Egypt, Sahara projects: HJT may still have a slight edge on pure temperature performance. For premium-aesthetic + hot-climate applications, BC + dual-glass also works well. For most hot-climate utility projects, HJT 730W or 740W remains our recommendation.

Same 25-year product + 30-year linear performance warranty structure as our TOPCon and HJT lines. Annual degradation spec 0.25-0.35%/yr (vs 0.40% TOPCon, 0.35% HJT), which translates to ≥87.4% output at year 25 and ≥84.8% at year 30. TUV-certified. Warranty claims handled directly by JUSTSOLAR Director — no regional office runaround.

Yes. Both dual-glass and single-glass BC 680W are available for private-label and OEM arrangements. Distributor private-label starts at 2 containers minimum with standard BC spec + your label. Full custom BC OEM (specific sizing, custom frame, proprietary packaging) starts at 50 MW annual commitment. BC OEM under a Tier-1 wrap arrangement is also available — contact us for project-specific assessment.