PERC was the main solar cell technology for years. N-TOPCon is its successor in many new panels: it uses n-type silicon and a thin “tunnel oxide” passivated contact, which generally gives higher efficiency and lower long-term degradation.
What is PERC?
PERC (passivated emitter and rear cell) adds a passivation layer to the back of a usually p-type cell, so more light is turned into power.
What does N-TOPCon change?
- N-type silicon: generally less prone to light-induced degradation than p-type.
- Tunnel oxide passivated contact: reduces energy lost where current is collected.
- Better bifacial performance: N-TOPCon cells are well suited to two-sided panels.
What does that mean for buyers?
More power per panel, so fewer panels for the same system, and a slower decline in output over the years. Tenzor Pulsar and Stellar panels are N-TOPCon bifacial: Stellar reaches a maximum module efficiency of 23.51%, and both series guarantee no more than 1% loss in year one and 0.40% a year after, with at least 87.4% of rated power in year 30.
FAQs
Are N-TOPCon panels more expensive?
Prices change with the market. Compare cost per watt and the performance warranty, not the panel price alone.
Can I mix N-TOPCon and PERC panels?
It is best not to mix different panels in the same string. Ask your installer.