Every module quote you receive in 2026 is either N-type or P-type silicon underneath, and the difference shows up in degradation rate, hot-climate yield and warranty length — not just the datasheet efficiency line. Here is what the two cell architectures actually mean for a procurement decision, without the wafer-physics lecture.
The one-paragraph physics
A solar cell is a silicon wafer doped to create an electric field. P-type wafers are doped with boron; the industry built two decades of PERC production on them because boron doping is cheap. N-type wafers are doped with phosphorus instead — more expensive to process, but the resulting cell suffers far less from the light-induced degradation (LID) that boron-oxygen defects cause, and it tolerates heat better.
TOPCon and HJT — the two dominant premium cell technologies — are both N-type. PERC is P-type. That is the practical takeaway: when a datasheet says TOPCon or HJT, you are buying N-type silicon.
Specification comparison
| Parameter | P-type PERC | N-type TOPCon | N-type HJT |
|---|---|---|---|
| Typical module efficiency (2026) | 20.5–21.5% | 22.0–23.0% | 22.5–23.5% |
| First-year degradation | ~2.0% | ~1.0% | ~1.0% |
| Annual degradation (year 2+) | ~0.45% | ~0.40% | ~0.25–0.30% |
| Temperature coefficient (Pmax) | −0.34%/°C | −0.29%/°C | −0.24%/°C |
| Bifaciality factor | ~70% | ~80–85% | ~90%+ |
| Typical performance warranty | 25 years / 84.8% | 30 years / 87.4% | 30 years / 88%+ |
What this means over 25 years
Take a 1 MWp array in a warm climate. The N-type advantages compound:
- Lower first-year LID — roughly 1% more energy retained from day one.
- Slower annual fade — by year 25, an N-type array typically delivers 3–5% more energy than PERC installed the same day.
- Better hot-weather output — at 65°C cell temperature, TOPCon loses ~2% less than PERC, HJT ~4% less. See our temperature coefficient guide for the full calculation.
- Higher bifacial gain — on ground mounts with decent albedo, N-type bifacial modules capture noticeably more rear-side energy.
The price question
In 2026 the TOPCon premium over PERC has collapsed to $0.005–0.01/W in most markets — N-type TOPCon is now the volume mainstream, and several manufacturers are phasing PERC lines out entirely. HJT still carries a $0.01–0.02/W premium due to lower production volumes and silver-heavy metallisation.
For most C&I and utility procurement, TOPCon is now the default rational choice: near-PERC pricing with N-type performance. HJT earns its premium in hot climates and space-constrained rooftops where its temperature coefficient and efficiency edge translate directly into revenue.
What to specify in your RFQ
- Cell technology (TOPCon / HJT) rather than just “N-type” — warranties and coefficients differ.
- First-year and linear annual degradation figures, written into the performance warranty.
- Temperature coefficient of Pmax if your site regularly exceeds 35°C ambient.
- Bifaciality factor for ground-mount or carport projects.
Econo Solar stocks N-type modules from LONGi, Jinko, Trina and JA Solar, with datasheets and FOB pricing available within 24 hours. Request a quote.