Types of solar panels: the 2026 technical comparison
In 2026, the PV module market consolidated around a few dominant technologies — TOPCon, HJT and a planned phase-out of PERC. Choosing the right module for a utility, agrivoltaic or industrial project is no longer a price-per-Wp question but a joint optimisation of efficiency, bifaciality, temperature coefficient and calendar degradation. This guide compares the four dominant families, gives 2026 efficiencies and explains VoltWatt's choices.
1. Why PERC is exiting
PERC dominated 2018–2023 at ~22% efficiency but suffers LID and LeTID and a 0.70 bifaciality cap. New n-type cells (TOPCon, HJT) eliminate these defects and reach 24–26%.
Tier-1 manufacturers (Trina, Jinko, LONGi, JA Solar) have announced PERC phase-out 2025–2027. PERC is now risky for new utility projects.
2. TOPCon: the 2026 standard
Tunnel Oxide Passivated Contact: 22.5–24.2% efficiency, –0.29%/°C temperature coefficient, 0.80 bifaciality, <1% first-year degradation. LCOE 4–7% lower than PERC. Majority technology in our utility and agrivoltaic projects.
3. HJT: high-temperature performance
Heterojunction: 24.5–25.8% efficiency, exceptional –0.24%/°C temperature coefficient, 0.90 bifaciality. Best for hot zones. 8–14% premium vs TOPCon; production less mature (Risen, Huasun, Meyer Burger).
4. IBC: rear-contact cells
Interdigitated Back Contact: 24.8–26.0% efficiency, no front shading, excellent low-light. Premium positioning (LG Neon R, SunPower Maxeon, Aiko); rare in utility.
5. Bifacial and ground role
Bifacial captures rear irradiance via ground albedo. Gain ranges 5% (dark ground) to 18% (white ground, snow). Optimum: HSAT, light ground, ≥1.5 m height. Agrivoltaics: 8–14% with lateral diffusion.
VoltWatt uses bifacial on all 2026 utility projects, except dark rooftops or polluted industrial sites.
6. Perovskite and silicon-perovskite tandem
Silicon-perovskite tandem is the expected 2027–2030 breakthrough. 33.7% lab efficiency (May 2025), 28.5% pilot module. Strong low-light response, broader spectrum. Limit: lifetime not yet proven, IEC 61215 accelerated testing in progress.
Frequently asked questions on panel types
- TOPCon or HJT?
- TOPCon for most temperate projects. HJT for hot zones (south Spain, Italy, southern France) where temperature coefficient matters.
- Is bifacial worth the premium?
- Almost always yes in 2026: €3–5/kWp premium repaid by 7–14% extra yield on light ground.
- Should we still buy PERC?
- No for new utility projects: risk on 30-year warranty and replacement module supply post-2027.
- Required warranties?
- Linear performance 30 years (98% year 1, ≥87% year 30), product 12–15 years. Tier-1 financial backstop and assignment to third party in case of default.
- Is perovskite reliable?
- Not yet in 2026 for utility-scale. Humidity and UV accelerated tests have not yet proven 25-year durability. Watch 2027–2028.
- How to verify module quality?
- Request IEC 61215 (electrical), IEC 61730 (safety), IEC 62804 (PID) reports, TÜV Rheinland or similar. Check positive power binning, wafer traceability, manufacturer financial strength.
Read next
Choosing the right module?
Our engineering team compares modules, simulates 25-year output and negotiates with Tier-1 manufacturers. Free techno-economic study within two weeks.
Talk to our technical team