Module efficiency, broken down
Efficiency is the share of sunlight landing on a module that leaves it as electricity, measured at standard test conditions - 1000 W/m², 25 °C cell temperature, AM1.5 spectrum.
It is a measure per square metre, not per panel. A more efficient module produces more from the same roof area; it does not automatically produce more than a physically larger panel, and it says nothing about how either behaves once the roof is hot. For that, read the temperature deep dive.
What the distribution shows
71.4% of everything tracked sits between 20 and 23%. Above that line the field drops to 2,286 panels, and the tail beyond 25% is thin enough that a record there describes one product line rather than a market.
Back Contact leads at 23.5% and CdTe trails at 18.5%, a spread of 5.0 points. The axis starts at zero on purpose - the gap between the best and worst architecture is real, but it is not the chasm a truncated axis makes it look. Every panel declaring an architecture is in here, 13,034 of them.
Power and efficiency rise together only because both track cell technology. Across the catalogue the correlation is weak: 180 Wp modules reach 23.0%, and there are 650 Wp modules below 21%. A panel's wattage tells you how much roof it needs, not how good it is.
The most efficient panels
By manufacturer
A catalogue average rewards a narrow, premium range and punishes breadth. AIKO leads on 144 panels; AE Solar's 654-panel catalogue spans everything from budget to flagship, so its average sits lower while its best module beats most of the names above it.
Manufacturers with fewer than 20 panels are marked in amber - one strong product line moves their average further than any amount of engineering moves a large one.
How these numbers are built
Every figure comes from a manufacturer datasheet ingested into the panel database. Nothing is modelled, estimated, or supplied by a brand outside its own published specification.
Aggregates recompute as new panels arrive. A panel that does not declare a value is left out of that average rather than filled in, so every figure here is backed by modules that actually publish it.
No paid placements, and no figure here reads which shops pay us a commission. Each power rating counts as the module it is. Bifacial datasheets that quote one module at several assumed rear-side gains are counted once, on their front-side rating.