Risen Energy RSM132 TOPCon

What the panel promises to still produce after 25 Australian summers. It compounds every year.

Rule: Worked out from the datasheet's first-year and annual degradation: 84% scores 0, 92% scores 10.

Covers defects in the panel itself. Twelve years is the floor; the best give 25 or more.

Rule: Years of product warranty: 10 scores 0, 30 scores 10.

Panels lose output as they heat up, and roof panels often pass 65°C in summer.

Rule: Temperature coefficient of Pmax: -0.38%/°C scores 0, -0.24%/°C scores 10.

More watts from each square metre, which matters most on small or broken-up roofs.

Rule: Highest module efficiency in the range: 20.5% scores 0, 25% scores 10.

How long the output guarantee runs.

Rule: Years: 25 scores 0, 30 scores 10.