What is P-Type Silicon?
Silicon doped with boron, used in older PERC cells, now being replaced by higher-performing N-type.
Quick Answer
Many UK systems installed before about 2023 use P-type PERC cells and continue to perform well. New installs increasingly use N-type. P-type panels remain available and cost-effective, but if you are buying new and weighing long-term output, N-type is generally the better option.
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
P-Type Silicon Explained
P-type silicon is doped with boron, giving it a shortage of electrons (positive charge carriers, or holes). It was the standard for residential solar for years and is the basis of PERC cells. Its main drawback is boron-oxygen defects, which cause light-induced degradation (LID), a small permanent loss of output in the first hours of sun exposure and slightly higher degradation over time. The industry is shifting from P-type PERC to N-type technologies (TOPCon, HJT) for better efficiency and longevity.
How Does P-Type Silicon Work in the UK?
Many UK systems installed before about 2023 use P-type PERC cells and continue to perform well. New installs increasingly use N-type. P-type panels remain available and cost-effective, but if you are buying new and weighing long-term output, N-type is generally the better option.
Frequently Asked Questions
Is P-type or N-type better for solar panels?
N-type is generally better: it degrades less, performs better in low light, and reaches higher efficiency. P-type (PERC) is older and cheaper and still works well, but for a new UK install N-type usually offers better long-term value.
What is light-induced degradation in P-type panels?
Light-induced degradation (LID) is a small, permanent drop in output that P-type cells experience in their first hours of sun exposure, caused by boron-oxygen defects. It typically costs 1–3% of output. N-type cells largely avoid it.
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John Rooney is the founder of Solar Info and has been covering the UK solar energy market since 2023. He researches every battery and inverter brand against manufacturer datasheets, MCS and Ofgem data, and feedback from the MCS-certified installers in our directory before publishing.